Shooting Infrared with Digital Cameras

Near Hanksville, Utah, taken during one of my workshops. D1x, Nikkor 20mm f/2.8 with Hoya 72 infrared filter. 5 second exposure (which generated noise in the dark areas). Brought into Photoshop, curves applied, slightly sharpened, then a more patterned noise added using Texture.

Infrared is a spectrum of light beyond that which we normally see. Despite having an IR blocking filter installed between the lens and the CCD, most digital cameras still react to infrared energy, though at levels far lower than visible light. To take “infrared” pictures—i.e., photos primarily made up of near infrared energy—you need to filter out the visible light and only allow the infrared spectrum through to the lens. The easiest way to do this is to use a Wratten filter, which you can find at most professional camera shops (see sidebar at right).

The Wratten series (and other dedicated infrared filters) are very dense filters, nearly opaque. Because they block most of the light, you’ll need very long exposures, so you’ll want to use a tripod.

Generally you should set your camera to B&W mode, as infrared filters remove most of the usable color information (it is amusing to bring a color infrared image into Photoshop and run Auto Levels on it, however). Also, note that incandescent lamps don’t put out much infrared (heat is thermal energy, not infrared), so you’ll probably want to start your experiments with landscapes. One other problem you’ll discover is that once you filter all the visible light, exposure times will be quite long. On a Coolpix 950 I get 1/2 second exposures or longer, while on my D1x I find my exposures are often measured in seconds.

Here’s one set of steps to try:

1. Focus. Once the filter is on, you won't be seeing much of anything until after the exposure, so focus is your first priority. Infrared light focuses at a slightly different point than visible light, so make sure that you use an aperture in Step 6 that has a decent depth of field.
2. Place the infrared filter in front of the lens.
3. Set the camera to manual exposure mode. I've found that the meter in most Nikon cameras, at best, does only a fair job of infrared exposures. On a D1, I almost always have to set exposure manually to get the proper exposure.
4. Set the camera to shoot B&W only. Optional: you can perform this step later; but it's easier to evaluate exposure with the camera set to B&W if that's how you'll print the image.
5. Set the camera to a higher ISO rating than usual. I usually set ISO 400 on my D1x. You'll be balancing ISO-generated noise with long shutter speed generated noise. On a D1, try to keep your exposures under 5 seconds; on a Coolpix, try to keep them under 2 seconds.
6. Set the exposure. Take a test exposure and examine the histogram. Since you're usually printing the final image in black and white you'll need a wide histogram that ranges from nearly pure blacks to nearly pure whites. Be careful at the bright end, however--foliage has a tendency to go to white in infrared, and you must retain enough working room to keep detail (e.g., don't let the histogram extend off the right side!). Adjust your exposure until you've got the broadest, workable histogram.
7. Take your shot!

Once you’ve taken an infrared shot, you’ll probably want to manipulate it a bit to make it better emulate the look of infrared film, which has unusual "color" (white foliage, for example) and a bit of graininess and bloom to edges. With Photoshop, try the following:

1. Remove the color, if any. If you’re working with a color image, select Desaturate from the Adjust submenu on the Image menu. Alternatively, you can also choose Grayscale from the Mode submenu on the Image menu, but this doesn't generate the best results.
2. Balance the image levels. The picture directly from your camera may look strange, as, despite your exposure efforts, it may still have most of the image data all bunched up at one or both ends of brightness range. Novices: select Auto Levels from the Adjust submenu on the Image menu. If you’re an advanced Photoshop user and want to preserve image data and get finer control, select Curves instead of Auto Levels, and adjust manually.
3. Sharpen the edges. The results so far will probably be a bit soft, so select Unsharp Mask from the Filter menu. Try starting at values of 100 for Amount, 2 for Radius, and 1 for Threshold, and then tweak as desired. Better still: use the Smart-Edge technique I describe in my Sharpening article.
4. Make it look grainy. Traditional infrared film is sharp, but grainy. To add grain, choose Add Noise from the Noise submenu on the Filter menu. Start with values of 20% and Uniform and tweak as desired. Alternatively, select Grain from the Texture submenu on the Filter menu. Start with values of Soft, 15% Intensity, and 50% Contrast and tweak as desired.
5. Add edge glow. Traditional black and white film tends to have an unnatural glow around edges, especially bright ones. Select Diffuse Glow from the Distort submenu on the Filter menu. Start with values of 6 for Graininess, 5 for Glow Amount, and 20 for Clear Amount.

Tip: Try these Photoshop steps with a regular, non-infrared image. You might be surprised by the results! (hint: before converting the image to black and white, try modifying the color channels individually, by lightening the red channel and darkening the blue.)

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technorati tags:photography, digital, infrared, IR, processing, photoshop

Infrared Photography Tips

Years ago I used to love to shoot Kodak High Speed Infrared Film. You never knew exactly what you would get until after it was processed. But oh, what amazing images could be made! Green foliage glowed white, people's skin could change to an ethereal complexion, and sunny skies could range from jet black to a rich silvery gray.

But exposure and composition was all guesswork. How much IR was in any given light? Your cameras light meter didn't know. Even focus was a guess, as IR light focused at a different point than visible light. And the really effective filters blocked all visible light - a severe handicap for SLR cameras.

All that has changed with the advent of digital cameras. Most have CCDs that are sensitive to the part of the spectrum known as "near infrared". Put a filter in front of their lens that blocks visible light, and the camera will automatically adjust its focus and exposure, showing you the resulting infrared image on your cameras LCD in real time. For those who experimented with infrared films in the past this is nothing short of a miracle.

What's Infrared Light, and Why Do Plants Seem To Glow With It?
Technically, the part of the spectrum that most digital cameras can see is called near infrared. It is composed of the frequencies just below visible red light, starting at a wavelength of around 700nm.
These frequencies often are absorbed or reflected quite differently than visible light. Most noticeable is the way that the internal structure of leaves strongly refracts near IR. The resulting brightness is dependant on the type of leaf and it's health. Other things, such as still water or a deep blue sky will absorb IR, and thus appear very dark. Some animals absorb infrared (reptiles especially), others reflect it.

Can My Camera Do This?
Most CCDs are sensitive to more than the visible light spectrum. This can cause problems with color balance, so manufactures often place a "hot mirror" in front of the CCD to block excessive infrared light. There is a simple way to tell if your digital camera is going to see IR. Just take a TV or VCR infrared remote control and point it directly at your camera. Push a button on it and look on the LCD for a spot of light. You should be able to see the infrared beam from the remote as a point of light. If you do, you will be able to shoot IR images with your camera.

Next, you will need to buy a filter that will block all visible light, but allow infrared radiation to pass. Different filters block varying amounts of shorter wavelength light. In increasing degree of strength are the Wratten #89B, Wratten #88A, Wratten #87, and Wratten #87C filters. I have had great results with an inexpensive 88A filter from Harrison and Harrison (1835 Thunderbolt Drive Unit E, Porterville, CA 93257-9300 phone 559-782-0121)

If your camera has no thread for a screw in filter, you can buy gelatin filters and cut them down to fit over your lens, and tape them in place. I find gelatin filters especially helpful for supplemental lenses like Nikon's fisheye. I just cut a small circle the size of the rear element of the lens, and place it between the camera and fisheye before I screw it in place.

Shooting Technique
When you place a sharp cut IR filter in front of your digital camera's lens, you are granted entry to an invisible world. Surreal landscapes unfold with unexpected graphic elements, such as inky black skies or open luminous shadow areas.

To compose really strong images in this netherworld requires close examination of your cameras LCD. This presents a problem since LCD screens are very hard to see in bright outdoor light. One solution is to use a LCD screen hood and magnifier like the Xtend-a-View™ (www.photosolve.com). This clever device fits over your camera's LCD, blocking all extraneous light, and magnifies your screen by a factor of 2x. Or just use a camera with an electronic viewfinder, like the Canon Pro90 IS or the Sony DSC-F707 Cyber-shot.

When I go looking for infrared images, I'll often walk with one eye to the LCD viewfinder and the other open to see what's around me. I shoot lots of images, as there are no expensive film and processing costs to deal with.

Depending on your cameras sensitivity, exposures can be fairly long, even in direct sun. The Nikon Coolpix 990 may need up to an 8 second exposure. I usually shoot at around 1/15 of a second with the more sensitive Coolpix 950, and 1/8 of a second with the Canon Pro90 IS. If your camera allows you to increase the apparent ISO, that will help a bit. Features such as the Coolpix's "Best Shot Selector" or the Canon Pro 90 IS's internal Image Stabilizer really help with long exposures. Each is so effective that I find I rarely need a tripod.

A tripod can be very useful, however, as it will allow you capture intriguing pairs of color and infrared images. Just shoot with the filter, then remove it and take a second shot. The two images will be in perfect register, and will allow you to experiment with mixing colors with your infrared later in a program like Photoshop or Paint Shop Pro.

Choosing your Subjects
Plants are quite spectacular in the way they glow. Healthy leaves can go almost white, while dead and dying vegetation is often quite a bit darker. The bark of trees can range from black to a birch like white.

People's skin can glow with a soft light, and occasionally a latticework of small veins can be seen just beneath the surface. Eyes can be quite spooky, as the iris can absorb or transmit infrared in unexpected ways.

Bodies of water can reflect IR if the surface is in motion, but will tend to absorb it if it is still. Shallow water is often quite transparent.

The sky will range from a light gray to black, depending on the angle you are shooting relative to the sun, and the amount of moisture causing backscatter. Clouds are often brilliant white, becoming strong visual elements.

Cityscapes can be richly varied, as buildings reflect and absorb different amounts of IR, and overall image clarity is often dramatic, as atmospheric scattering of near IR wavelengths is generally quite low.

Post Processing the Image
Your infrared images may have some strange color and tonal balance to them right out of the camera. Some may go quite red; others may have a cyan sheen. Rarely will they have a full tonal range.

Using a program like Photoshop will allow you to clean up the image, adjusting curves and levels. I like to convert my RGB images into true grayscale before I print them. Sometimes I'll simply desaturate the image, other times I find there is less noise in the image if I converted to LAB mode first, choose the lightness channel, and then convert to grayscale.

Photoshop also provides the means to produce other classic infrared film effects. Kodak High Speed Infrared Film was quite grainy, and had no anti-halation backing. This caused the highlights to flare and glow with a soft, dreamlike effect. You can add both these effects to your digital images using Photoshop's Diffuse Glow filter.

Printing Your Images
Inkjet printers can do a marvelous job of creating black and white prints. I've been blown away with the new Canon S800, a six-color printer that uses individual ink cartridges. My black and white infrared prints have rich, deep blacks, and sparking highlights. With a simple color adjustment I can print sepia tones, or neutral toned prints.

For anyone who has experimented with infrared film, shooting digital infrared will seem like a dream come true. Being able to preview the results in real time is critical to composing the most effective images. For wedding photographers thinking of offering IR shots as an added feature, digital allows instant results as well as the ability to shoot color with the simple change of filter.

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Infrared Photography with a Digital Camera

It was more than thirty years ago when I last experimented with photography in infrared. Too much hassle: special film handling, black-and-white processing, inability to evaluate results (and adjust settings) until the whole roll was exposed and pictures were printed...
Now this has changed. Due to the arrival of digital photography, we can take infrared pictures whenever we please, mixing them with "normal" ones, and see results on the spot, tweaking the settings to our hearts' desires... All depends, of course, on how your camera sensor array reacts to the infrared — and, depending on the filter you are using, to the far red end of the visible spectrum.	Olympus C-5060WZ, Hoya R72 filter

What's so different about infrared? At the first glance, a monochrome picture taken in infrared may look similar to just another black and white photograph. And then you start seeing differences: objects which are bright in visible light (like sky) look dark here, while some of those which are "normally" dark (green foliage) acquire a bright glow. An unusual and eerie feeling.
This can be explained with the graph at the right, showing the fraction of light reflected off various materials at various light colors (wavelengths). The height of the curves to the left of 600 nm shows how bright these materials are in visible light; to the right of 700 nm — how bright they are in infrared. The most dramatic difference between the visible and infrared spectrum is in case of foliage: it does, indeed, become very bright in infrared; very much like you can see in my photographs shown here. (Source: Kevin Frankel at al., Concealment Of The Warfighter’s Equipment Through Enhanced Polymer Technology, 24th Army Science Conference Proceedings, Orlando, FL, 2004)
To answer the question briefly: photographs in infrared show quite unusual tonality, different than that to which we are used, and this may make them esthetically pleasing, at least in many cases. Which, of course, is a matter of taste. The camera First, you need a digital camera. Digital cameras have a special infrared-blocking filter in front of the light-sensitive CCD array, as the IR light degrades the visible-light color rendition (the CCD itself reacts to wavelengths up to 1000 nanometers and even longer). The question is how much of infrared will the filter let through. Some of the early models, like the venerable Olympus C-2000Z/C-2020Z (but not the '2040!) and Nikon 950, were quite permissive here, but the more recent models let just enough of IR light through to be suitable for infrared photography; most of these, while requiring quite long exposures, also offer a workable solution. Remember, camera makers do everything to stop the infrared from reaching the sensor! For example, using the Hoya R72 IR filter (perhaps the most useful kind) on a present-day Olympus E-500 requires exposure adjustment by about 11 EV (F-stops), or by a factor of 1500 to 3000 (1 EV corresponds to doubling or halving the amount of light). As a matter of fact, I would classify all digital cameras I have used in the last five years as barely usable for infrared shooting — which does not preclude getting very nice results from them anyway. For comparison, the C-2000Z needed only a 7 EV (130×) adjustment, being about 15 times more sensitive. For illustration purposes, here is a brief comparison of IR sensitivity for some Olympus cameras I have used in the last few years to shoot in infrared. All data is shown for the Hoya R72 filter, sunny daylight; the values are accurate to 0.5 EV or better. The Typical Exposure data corresponds to a sunny day outdoors, ISO 100.

Camera	C-5050Z	C-5060WZ	E-10	E-20	E-300	E-500
Exposure Factor	11.5 EV (3000×)				7.3 EV (150×)	10.3 EV (1300×)
Typical Exposure	2 seconds at F/4				1/8 s at F/4	1 s at F/4

For other cameras, check for yourself before investing into any filters. You may also find data on selected models at Jen Roesner's site. A few of the Sony models (Sony DSC-F707/717/818 in this number) allow you to move the anti-IR filter out of the light's way; unfortunately, Sony went to great measures to make this feature unusable in daylight, as it is supposedly making some clothing partially transparent to infrared. (I would also like to turn Sony's attention that the big lens in the '717 can be used to hurt babies and puppies.) Some people modify their cameras by removing the anti-IR filter (sometimes replacing it with a glass plate of equal thickness). This is a tricky operation, but it will usually increase the camera's IR sensitivity dramatically. Obviously, the camera's color performance in visible light will be degraded, and your warranty will be voided. SLR — the second choice Digital SLRs are not my first choice for infrared, for a two major reasons. First, this class of cameras (with a few exceptions, see below) does not offer real-time electronic preview, because the light from the lens reaches the sensor only during the actual exposure. This means that you have to put the camera on a tripod, compose the picture without the IR filter, then put it on and shoot blind. Two notable exceptions are the older Olympus E-10 and E-20 SLRs which use a beam-splitting prism and allow for real-time preview, and the more recent Olympus (again!) models, with the Live View feature: the E-330, E-410, and E-510. Second, the light metering in digital SLRs is not done by the image sensor itself (like in non-SLR models), but by a separate set of sensors, which may have a different response to infrared. You cannot rely on camera's autoexposure (although you may be able to work out a correction applicable to a given camera/filter combination). This is why for infrared I prefer optical finder, non-SLR cameras, like the C-5050Z or C-5060WZ (or the two-of-a-kind E-10/E-20 as mentioned above). A hardcore infrared aficionado may decide to splurge $1800 to get the Fuji S3 Pro UVIR. This is a modification of the "regular" S3 Pro, intended for photography in the infrared or ultraviolet part of the spectrum. In this model, the anti-IR filter (also blocking UV light) in front of the CCD has been replaced with a plain glass plate, so that the overall infrared sensitivity is vastly increased. The camera also allows for live digital preview of the image, very much like in the Olympus Mode B (see the section on image preview below), but limited to 30 seconds. I've never used the S3 (modified or not), so I will not go into details; besides, if you are interested in it, you probably know more about infrared photography than I do. In any case, I wasn't able to find any infrared samples from this camera on the Web, so I do not think it is much used outside of scientific and law-enforcement applications. The IR filter Then you need an infrared filter. You can buy these from any dependable mail-order supplier, like B&H Photo. Various filters may differ in the visible light cut-off point (see the table below). The Wratten #89B (available as Hoya R72), with the light transmission falling down to 50% at 720 nanometers, seems to be most popular and gives the greatest chance of success. The darker #87 or #87C may or may not work, depending on the camera, while the almost-IR #70, while allowing for shorter exposure times, does not provide the eerie Woods effect on greens. You also need a way to attach the filter to your lens. This is easy with SLR and digital-finder models, but digital compacts may pose a problem. WIth very few (like the Olympus C-5060WZ) you can do it directly, as the lens is threaded; with others (actually, all other compacts on the market) you will need a lens adapter tube, like the 41-43 mm CLA-1 attachment for the Olympus C-5050Z (plus a step-up ring). A tripod is essential. For the #89B (R72) filter you will be getting exposures of 1-2 seconds or more at F/4 and ISO 100.

	Olympus E-20, Hoya R72	Olympus E-20, Hoya R72
IR filter summary Here is a brief comparison of the infrared filters, including those made by B+W, Hoya, and Tiffen as of November, 2004, Those generally available in glass (as I've checked at B&H in November, 2004) are marked in bold. Some are available as gelatine foil only. The filters are listed in order of increasing "blindness" to the visible light. The "0%" column shows the wavelength below which the filter has zero transmittance (i.e., lets no light through), while "50%" — the wavelength at which the filter blocks half of the incoming light (50% transmittance).

Wratten	Schott	B+W	Hoya	Tiffen	0%	50%	Remarks
#25	OG590	090	25A	25	580 nm	600 nm	Really a red filter
#29	RG630	091	-	29	600 nm	620 nm	Dark red
#70	RG665	-	-	-	640 nm	680 nm	Very dark red
#89B	RG695	092	R72	-	680 nm	720 nm	Almost "black", but not quite
#88A	RG715	-	-	-	720 nm	750 nm	I've never seen this one
#87	RG780	-	-	87	740 nm	795 nm	Cuts off all visible light
#87C	RG830	093	-	-	790 nm	850 nm	Usually called "black"
#87B	RG850	-	RM90	-	820 nm	930 nm	Expensive! $250 & up!
#87A	RG1000	094	RM100	-	880 nm	1050nm	Blocks even some of infrared

The data above is quoted after W.J. Markerink. For those who would like to have a closer look at IR filter transmittance, here is a graphic representation:

The graph shows the transmittance of various filters as a function of the wavelength. It is based on data by Paul Repacholi (Curtin University of Technology, 1992), posted by W.J. Markerink and also by Eric Cheng. The logarithmic scale is used here, as it fits the problem better: differences, say, between 1% and 10% are by far more meaningful than those between 91% and 100%. It can be clearly seen that #89B (R72) still allows through some of the far red (just below and around 700 nm), #87 starts only around 740 nm.

Just a reminder: the human eye is sensitive to wavelengths up to 700-720 nm or so. Because the anti-IR filters in digital cameras block most of the infrared, even slight differences in filter transmittance may have strong effect on results (and exposure). Therefore two filters listed as equivalent in the table above may deliver slightly different results on a given camera. Recommendation: I believe the most useful, general-purpose IR filter for digital photography is Hoya R72 (#89B). It blocks visible light well enough (if not entirely) to provide a well-pronounced IR effect, while still allowing for non-exotic exposure times. This filter should work fine with most of mid- to high-end amateur digital cameras (your mileage may vary, so check with someone who tried it on your camera). The small amount of visible (far red) light which this filter lets through does not affect pictures enough to spoil the IR effect, while coloring your images red (or purple), therefore they need to be converted to monochrome in postprocessing. The #87 filter is more expensive and more tricky. Many digital cameras will not be able to "see" through it, while some others may work — again, check with their users. I have tried it with the Olympus E-300: the exposures are much longer Image preview As mentioned in the SLR section above, most of digital SLRs do not allow you to use the LCD monitor for picture preview and composition. You have to compose in the optical finder without the filter (using a tripod, of course), then put the filter on the lens, and shoot blind. If you have a digital SLR and intend working in infrared, you may be better off getting an inexpensive non-SLR model specifically for infrared. You need a small backup camera anyway. Digital non-SLR cameras (including EVF ones) are more convenient in this aspect, as you can view and compose the image on the monitor as normal; the preview will be red or purple, of course, and quite dark, but usable for these purposes. As mentioned before, the E-330, E-410, and E-510 from Olympus do not suffer from this: their Live View feature allows for electronoc image preview with the filter on. Exposure setting All digital cameras I know measure the light through the lens: most non-SLRs use the CCD itself to do that, while SLRs (except for the E-10/E-20, again) have dedicated metering sensors for which some of the light used for viewing is diverted. This means that you can, with most cameras art least, trust the exposure automation — as long as the metering system is capable of doing its job at the very low light levels. It should be: a typical IR exposure with the R72 filter corresponds to exposure value of EV 3, while most cameras can cope with EV zero or close. This is especially applicable to non-SLR cameras, using the CCD for metering, as already mentioned. Still, even with these cameras usually you will have to apply some exposure compensation, usually -0.7 or -1 EV, for the reasons described below. In SLRs, a separate light sensor does the metering; its sensitivity to the IR may be entirely different than that of the CCD imager; therefore you may have to apply a significant exposure compensation to get things right. A few test shots should be enough to establish the value appropriate for a particular camera. For example, I can reliably shoot IR with the Olympus E-300 in the autoexposure mode, but I have to apply a +4 EV compensation. When setting the exposure compensation (SLR or not), you have to aim for a picture which will look like it is underexposed, too dark. This is because practically whole image information goes into just one of the RGB components: red, and you have to keep that component from saturation (i.e., running out of range). If your camera can display a brightness histogram for individual RGB components, make sure that the red one does not hit the upper limit.
Your exposures will be quite long: an IR filter combined with the camera's anti-IR one will let through less than 0.1% of the incoming light. A bright scene, requiring 1/500 s at F/8 in visible light will need about 1 s or longer at F/4 on most cameras. Not only this asks for using a tripod, but, if the air is not quite still, there will be a blur in the foliage, grass, water reflections, etc. This is not necessarily a bad thing, and it may add an extra feel to the image. Here is an example. I like the contrast between the sharp (immobile) planks, and the fluid, fuzzy grass. A matter of taste, of course, but it was quite windy that day.	Olympus E-500, Hoya R72 (XGA here)
Fogging Certain camera models (SLR or not) may exhibit some fogging, or image areas with extra exposure (for example, a bright central spot some Canon Digital Rebels). This may be due to light scattered from inner surfaces of the camera body and/or lens; perhaps the black coating of those is not black enough in infrared? Sometimes it happens to all cameras of a given model, sometimes — just to a particular specimen or a particular lens. Camera makers are not worried about this: very few users ever venture into the IR realm, and this is a mass market after all. There is no way to avoid this problem; once again, check an IR filter on your camera before buying. Note to SLR users: regardless of that effect, the image may be fogged, or otherwise affected, by the light entering through the viewfinder in spite of the raised mirror) and reaching the sensor after being scattered around the mirror chamber. To avoid that, close the eyepiece shutter before the exposure, or use the included eyepiece cover (or, at the very least, shield the eyepiece with your hand or hat). Users of non-SLR cameras, obviously, do not have to worry about this. Focusing The focal length of your lens (and therefore the proper focus setting) depends on the wavelength. Lens makers try to keep that dependency to a minimum (achromatic lenses), but only within the visible light spectrum. As soon as you are into infrared, the chromatic aberration curves go astray. Because autofocusing in most digital cameras is done through the lens, the focus shift is automatically taken care of. Therefore it may be safer to let the camera focus — as long as it is capable of doing that at low light levels (down to EV 0, as usually quoted for an F/2 lens). Most cameras are, but not very reliably, so I would recommend taking more than one picture, every time forcing the camera to re-focus. Doing that, no IR-related corrections to focusing are necessary. Setting the focus manually may not work any better, as the distance scale corresponds to focusing in visible light. If in doubt, try setting focus a little closer than the actual subject distance: at the equivalent focal length of 50 mm use about 4-5 m instead of infinity — but this actually depends on the particular lens. My early digital experiments, setting the Olympus E-10 to infinity, resulted in very unsharp pictures. If you want to focus manually, you'll have to do a series of test shots. Depth of field may, to a large extent, help masking the lack of proper focus. In case of problems, try to use wide zoom settings and shoot in aperture priority at F/8 or so; this may help. Postprocessing The response of red, green, and blue photosites in the CCD, and therefore the color image recorded by the camera, is the result of a subtle play between the transmittances of three (!) filter layers involved here: (1) the IR filter mounted on the lens; (2) the anti-IR filter in front of the CCD; (3) the tiny red, green, and blue filters in front of each photosite of the sensor. No wonder that the (false) colors of an image shot in infrared may vary from one camera model to another, and from filter to filter used. While some cameras, especially when used with filters darker than #89B, may come up with color images which some may find pleasing, in most cases the images will have a very strong red or purple-red tint, being recorded mostly in the red component. This is certainly true of all Olympus models I have used, but not only. The effect may also depend on the sensor gain (ISO setting) and color balance, but not by much. Therefore usually you would like to translate your IR pictures into gray scale, i.e., to black-and-white (or sepia) monochrome. Depending on your postprocessing program, you can do it by desaturating the image, or changing its mode to 16-bit monochrome, or applying a duotone filter. After the conversion you will usually want to restore the tonal range of your picture (doing that before does not make much sense, as this usually leads to overloading of the red channel and burning out the highlights). Then, after denoising (see below) and, if needed, some sharpening, you may tint your monochrome picture to sepia or something else, although I usually prefer my IR pictures straight black-and-white.

Retaining some color information
Your infrared images do not have to be monochromatic (like black/white or sepia). There is some color information in the image file, and while it has nothing to do with reality, it may be used to generate quite pleasing images. The easiest way to do that is to split your image into individual RGB components, adjust each separately, and then recombine them. Here is an example of such a treatment, borrowed from my C-5060WZ infrared sample page, where you may find more details on how the image was postprocessed.		Olympus C-5060WZ, Hoya R72
Another field for experimentation opens itself if you have two versions of the same image (identically framed): one shot with, and one without an IR filter. Bringing both into an image editor, splitting them into R, G, and B layers, and then recombining the R layer from the IR image with G and B (possibly swapped) from the visible-light one gives efefct which is sometimes compared to that of the Ektachrome false-color IR film. Some tonal adjustment of individual layers before recombining them may improve the effect.
The red layer from an IR image combined with green and blue ones from a visible-light picture.	Frankly speaking, this is too intrusive for my taste, and the effects will be eye-pleasing for very few subjects. The example I'm showing at the left is just plain ugly. You may have more luck (or skills). In general, I prefer my infrared pictures to be monochrome, sometimes tinted just a bit towards warmer shades.

Image noise Infrared images exhibit more noise than visible-light ones. First of all, the exposures are 1000 times or so longer than in "normal" pictures, and that's when the noise always shows up. Another factor is that the image is created mostly in the red component, i.e., using only the R (red-sensitive) photosites of the image sensor. In the most commonly used Bayer matrix arrangement, out of each four photosites (sometimes wrongly referred to as pixels in this context) one records red, one blue, and two — green component of the image. Only when the raw image is being converted to RGB, the missing values are interpolated, so that a pixel (all three components) is created for each photosite location. This means that your eight-megapixel camera records just two megapixels of information, plain and clear; for the R and G photosites the whole signal is just interpolated from their R neighbors. The photosite size, however, remains still at the 8 MP level, just 25% of what it would be for a 2 MP sensor of the same physical size. Last but not least, the image has to be kept within just a partial luminance range (read: dark), to avoid overloading the red channel, as I already described above. For a more natural look this limited tonal range will have to be, after desaturation, stretched to the full luminance range. This leads to (usually) doubling of the visible noise amplitude. One may argue that the last two effects partially overlap, i.e., I am listing the same thing twice, but still — the noise is there, much more of it than in visible-light images, be it color or monochrome. Some photographers (especially those who never printed anything above 4x6" from their film cameras) are allergic to noise in digital images. Others, however, are so used to the large grain in infrared films, that they consider the noise a part of the "infrared look" and want to emulate the effect in the digital medium. If you dislike noise in your IR images, tough: it will be there. You will have much more of it than in "regular" color pictures. If you find the noise objectionable, try to keep it down by using the lowest ISO setting of your camera and opening the aperture as wide as your lens allows (this will, however, reduce the available depth of field, not always desirable, especially in view of possible focusing problems, already discussed). Remember also that the infrared image should be underexposed only enough to avoid the red channel overload — but not more, as this will result in more noise amplification when the tonal range is restored. If you are not sure, use exposure bracketing until you get the hang of it. Much of the noise can be removed quite well with use of an image-processing program, or, usually more effectively, with a dedicated noise removal application (or plug-in), like, for example, Neat Image. The latter does a very good job, and has a wide range of available adjustments. Still, we are walking a tightrope here. While a moderate amount of noise can be often removed quite nicely, quite often I find that really noisy images look better without that operation, which often leads to excessive loss of texture detail and an unnatural, plasticky look. Be careful and keep the originals in case you change your mind later. Many photographers, to the contrary, like the noise effect, as it is often associated with the "classic", grainy infrared look. Actually, from time to time I'm receiving emails how to bring more noise to infrared images! To emulate the IR film grain effect, some writers recommend adding artificial noise in postprocessing. I'm not happy with that technique, preferring rather to intensify the natural noise pattern of the CCD. This can be done by setting the CCD sensitivity to the equivalent of ISO 400 (or higher, if your camera allows it). With all cameras I've tried, a one-second exposure at ISO 400 shows more noise than a four-second one at ISO 100, so this will help. As a side effect, it will also reduce the exposure time. To make the noise more visible, you may also underexpose your pictures by one or two EV, and then stretch the tonal range in postprocessing to recover the shadows and highlights; this will also amplify the noise considerably. This technique takes less time to apply than to describe, see an example below. Just remember that the tonal smoothness of the result may be affected, therefore it may be better to convert your image to 48 bits (16 bit per color), do the processing, and only at the end convert it back to 24 bits. The noise amplitude will remain unaffected by the switch to 48 bits, but the tonality will be smoother.

	Olympus E-20 at ISO 320, Hoya R72, underexposed and re-equalized after desaturation	A 1:1 sample from the image at the left
In most of my infrared images, however, I'm happy with the amount of noise as it is, with no need to reduce or to increase it. Almost infrared: a deep-red filter The easily available Wratten #29 (B+W #91) deep-red filter will also deliver quite dramatic monochrome effects (although not as strong as these obtained with the #70). But, importantly, with the light loss of only about 8x (3 EV) it can be used safely without a tripod. One of my Readers reported success using such a filter for IR photography. To get rid of the visible-light component, he would remove the red layer of the RGB image, leaving only the green and blue layers. As these are virtually blind to red, only the IR input would be left. While this might work with some cameras (he used a non-SLR Nikon), my experiments with the Olympus C-5060WZ ended up with negative results. The green and blue image layers, as dark as they were, did not show any Woods effect. This indicates that their IR sensitivity is even lower than that for the red light. I've tried the same approach with a #70 filter, also to no avail.

Olympus C-3000Z; Wratten #70

A deep-red filter may still provide very nice monochrome images, as long as you do not have to have the Woods effect. I'm using it from time to time, and the extra advantage is that with the exposure multiplier you can get away shooting from hand. Some examples are shown in my C-3000 almost-IR sample page.

What to shoot in IR The most rewarding subject to shoot in infrared are sunny outdoors scenes, especially with lots of foliage, grass, and water, preferably with some nice, white clouds in the sky. Morning and evening sunlight is richer in infrared than midday one, so the glowing Woods effect in the foliage will usually be more pronounced. As always in photography, this, however, is not an iron-clad rule. Sometimes an image shot under a cloudy sky may carry a strong visual message as well. For example, I like the one shown in the preceding section. I shot another frame at the same location on a sunny day, and it was, I would say, more trivial. Buildings, especially with bright walls, look really good on the background of the dark, almost-black sky. Some people recommend IR for shooting cemeteries, as the subject goes well with the unreal feel of the medium — but, after all, how many cemetery pictures can you take?
Don't limit yourself only to the bright greens and dark sky. Even scenes without those telltales of infrared will have a different tonal gradation than a "normal" picture converted to B&W. Look, for example, at this one. Looking at this picture (shot at 1/8 s and F/1.8) now, I think I should have closed the aperture down to F/8 in order to have most of the people shown as streaks of movement at the exposure of 2.5 seconds; with some luck I could get one stationary person in the middle, a real keeper. Well, next time.		Olympus C-5050Z; Hoya R72 (XGA here)
The eerie atmosphere of IR pictures goes well with adventurous, off-balance composition. Remember the pictures you were taking as an 18-year old, aspiring photographer? Try that again. (I will, too, try to break that lame habit of neat, even framing, acquired after having grown out of that period.)
Olympus C-5060WZ, Hoya R72 filter	Infrared is not a common medium for people shots, but I have seen some very good IR portraits. Outdoors portraits or nudes with the surrealist background may have a strong impact. The skin becomes more white, with most imperfections (and texture) gone, which may be related to the partial transparency of its outer layers to the longer wavelengths, and the porcelain-like tonality quite interesting. Check out, for example one of Eric Cheng's IR galleries (shot with a modified camera, with the IR-blocking filter removed).
Web resources Back in 2000, when this article was originally posted, there was a scarcity of any IR information on the Web (the first three items on the list below being notable exceptions). With the popularity of digital medium, however, there is more information available now. Here are pieces which attracted my attention. Clive Warren's Infrared Photography FAQ — a good introduction to the subject, covering both film-based and digital aspects; Jeremy McCreary's Infrared Basics for Digital Photographers — an excellent article on the subject at his dpFWIW digital photography site; Eric Cheng has a rich IR section on his photography site; Digital Infrared Photography Made Easy, an article at Apogee Photo; Experiments with Digital Infrared Photography by Ross Alford is a nice article with some pointers on obtaining interesting pseudo-color effect by image layer manipulation. Jen Roesner from Germany has a whole site dedicated to digital infrared photography, including a comparison table of various cameras' IR sensitivity.

SOURCE

technorati tags:photography, digital, infrared, technique

Programul Nikon în prim-plan

La Nikon, toate categoriile de preţ ale SLR-urilor sunt bine reprezentate: cumpărătorul are posibilitatea de a alege între cele şapte modele, cu preţuri cuprinse între 450 şi 4.500 euro, iar oferta de obiective AF şi accesorii e foarte diversificată. În articolul de faţă încercăm să analizăm cât mai complet sistemul de produse SLR de la Nikon.

Treaba merge foarte bine pentru Nikon de când producătorul japonez a început să înregistreze succese pe trei planuri deodată: D2X a câştigat tot mai mult teren în domeniul profesional, D200 în segmentul semiprofesional, fiind cel mai bun aparat foto la clasa sub 2.000 euro. Şi, în final, Nikon a reuşit să-şi croiască drum la categoria sub 1.000 euro prin două modele: D80, un aparat SLR digital de 10 megapixeli, şi D40 – model SLR de bază cu un concept de utilizare inovativ.
Indiferent de clasa de aparate foto din care fac parte, toate modelele de la Nikon au acelaşi lucru în comun: senzorul de imagine de format APS-C cu factorul de unghi vizual 1,5. Astfel, la un obiectiv de 50 mm se îngustează câmpul vizual la nivelul unui obiectiv clasic de 75 mm. Lipsa unui senzor full frame este însă la Nikon o chestiune de optică: dacă ar trece peste 15 megapixeli, un senzor full frame ar avea mai multe rezerve, iar fotografierea ar fi mult uşurată prin focalizarea selectivă şi gradul de detaliu foarte mare în colţuri.

Pe de altă parte însă, senzorul de format mai mic permite construcţia unor obiective mai compacte şi mai rezonabile ca preţ, cu un câmp vizual mai redus faţă de obiectivele pentru full frame (pe film). Nikon are în prezent opt astfel de obiective cu prescurtarea DX în denumirea produsului, aproape toate cu motor ultrasonic (AF-S Nikkor). Această tendinţă de încorporare a motorului ultrasonic în obiectiv e foarte clar scoasă în evidenţă de noul aparat SLR, D40, care este primul model de la Nikon fără motor ultrasonic încorporat. Obiective AF-S compatibile cu fotografia digitală pot fi găsite şi printre tipurile non-DX. Mai multe despre acestea la capitolul obiective din acest articol.

Pentru începători: D40 cu 6 megapixeli
Nikon D40 (600 euro în kit-ul cu obiectiv standard) se prezintă ca fiind noul highlight la clasa de bază. Aparatul are în comun cu D50 (450 euro) şi D70s (600 euro) un RGB-CCD de 6 megapixeli. Şi totuşi, noul aparat are o calitate a imaginii cu mult mai bună: la ISO 100 şi ISO 400 obţine punctajul maxim, 15 puncte, la nivelul de zgomot de imagine, în timp ce D50 trebuie să se mulţumească cu doar 13,5/11 puncte, iar D70s cu 14/11,5 puncte. Observăm o evoluţie şi la contrastul de detaliu, care acum este de 9,5/9 diafragme la ISO 100/400, iar la ISO 800 - 8,5 diafragme. Toate aceste lucruri cântăresc în practică mai mult decât saltul înainte făcut de D70s, la calitatea imaginii la ISO 100.Cu totul nou este conceptul de utilizare al lui D40, Nikon lipsindu-se pentru prima dată la un SLR de cel de-al doilea ecran LCD pentru afişarea parametrilor expunerii. Pentru aceasta se foloseşte de ecranul TFT obişnuit, cunoscut deja de la Canon EOS 400D, Sony Alpha 100 şi de la unele modele Olympus. Display-ul de 2,5 inchi asigură o vizibilitate foarte bună şi permite vizualizarea grafică a unor parametri, cum ar fi diafragma, a cărei deschidere variază odată cu diafragma de lucru efectivă. Accesul la cele mai importante funcţii, cum ar fi sensibilitatea, balansul de alb, rezoluţia, măsurarea expunerii, modul AF, corecţia expunerii şi a bliţului, este asigurat la fel de rapid şi necomplicat prin ecranul LCD. Pentru a ajusta un parametru, se deplasează un marcaj galben cu ajutorul tastelor-săgeţi spre câmpul dorit. Apoi se activează câmpul (la care se şi afişează o imagine demonstrativă), modificaţi parametrul şi confirmaţi. Procedura este logică şi uşor de stăpânit, însă ar putea fi mai rapidă – de exemplu, prin modificarea directă în câmpul marcat cu galben cu ajutorul rotiţei de scroll. Acest lucru este însă posibil cu ajutorul tastei Fn, căreia i se pot atribui până la cinci funcţii diferite. Dacă cele 17 funcţii individuale vi se par derutante, se poate utiliza o selecţie de doar 6 parametri ori se poate configura un meniu individualizat. Atât această opţiune, cât şi meniul „Image edit” au fost implementate în D40 de la D80. Printre funcţiile de prelucrare ar fi interesant de amintit funcţia „D-Lighting” care ajustează în trei trepte contrastul. În loc de un vizor cu prismă ca la D80/D200, în D40 a fost încorporat un vizor cu oglindă cu o reprezentare efectivă a imaginii mai redusă. Faţă de D50/D70s, imaginea din vizorul lui D40 este totuşi ceva mai mare, magnificarea efectivă fiind de 0,54 faţă de 0,48. În schimb, a fost redus sistemul AF, care acum trebuie să se descurce doar cu trei câmpuri dispuse orizontal; D50/D70s aveau la dispoziţie cinci câmpuri. D40 declanşează însă mai rapid: 0,36 secunde întârzierea de declanşare inclusiv AF – o valoare de nivelul unui D80 sau D200. Spre comparaţie, Nikon D50 şi D70s declanşau după 0,48 secunde, respectiv 0,44 secunde. Doar la timpul de pornire, D70s se dovedeşte a fi net mai rapid: 0,2 secunde faţă de 0,6 secunde. Pentru prima dată un SLR digital de la Nikon vine fără motor AF. În ciuda baionetei nemodificate mecanic, D40 poate să folosească doar obiective de tip AF-S şi AF-I cu motor AF integrat, limitând astfel numărul de obiective din gama Nikon la mai puţin de 20 de modele, mai ales că multe dintre obiectivele de la producători terţi sunt incompatibile. În tabelul nostru veţi găsi lângă D40 şi modelele D50 şi D70s, foarte rentabile în prezent. Totuşi, noi vă recomandăm, în ciuda preţului mai ridicat, modelul D40, datorită rezultatelor mai bune la ISO 400, cu excepţia situaţiei în care aveţi deja numeroase obiective Nikkor (în afară de cele AF-S şi AF-I) şi doriţi să le folosiţi în continuare.

Pentru avansaţi: D80/D200 cu 10 megapixeli
Nikon D200 (1.400 euro) punctează ca aparat foto semiprofesional prin dotarea sa de primă clasă şi prin performanţele sale excepţionale: 57,5 puncte (ISO 100), respectiv 54,5 puncte (ISO 400) pentru calitatea imaginii, cele mai bune valori la aparatele din clasa sub 2.000 euro. Aparatul de 10 megapixeli reuşeşte să convingă atât la nivel de zgomot de imagine (15 puncte la ISO 100/400), cât şi la rezoluţie (1173 PL/ÎI la ISO 100). Nici la balansul de alb, fidelitatea de culoare sau la contrastul de obiectiv nu-i putem găsi niciun cusur demn de amintit. În ceea ce priveşte dotarea, nu lipsesc accesorii profesionale cum ar fi de exemplu adaptorul WLAN WT-3 sau posibilitatea de conectare la un receptor GPS pentru salvarea coordonatelor geografice în informaţia fotografiei. Carcasa e construită dintr-un aliaj de magneziu şi este etanşeizată contra prafului şi umezelii. Greutatea sa de 830 g îl face să stea foarte bine în mână, fapt la care contribuie din plin şi cauciucarea mânerului. Graniţa dintre un aparat profesional şi unul pentru amatori dispare la acest model, cu excepţia prezenţei bliţului încorporat. LA fel ca la modelele profesionale de la Nikon, D200 poate fi utilizat împreună cu obiectivele Nikkor AI cu focalizare manuală în programul prioritate de timp. Display-ul TFT de 2,5 inchi are o rezoluţie de 230.000 pixeli şi permite o vizibilitate de până la 170 grade vertical/orizontal. Aparatul foto poate fi reglat după dorinţă prin nu mai puţin de 45 de funcţii individuale, aceste setări putând fi salvate pe patru locuri de salvare. Pentru a uşura utilizarea lor, funcţiile individuale au fost împărţite în şase grupe. Modulul de focalizare automată Multi-CAM 1000 ridică noi ştachete la această clasă de aparate foto. Puteţi reduce numărul total de câmpuri de măsurare, de la 11 la 7 câmpuri mărite, permiţând astfel focalizarea mai uşoară pe subiecţi în mişcare. Câmpurile de măsurare pot fi selectate individual sau în grupe, pentru a putea focaliza confortabil pe porţiunea centrală a subiectului. Întârzierea de declanşare este de 0,36 secunde, D200 fiind întrecut clar de concurentul de la Canon la acest punct, EOS 30D (0,25 secunde). Acumulatorul Li-ION EN-EL3e permite 100 de declanşări cu o singură încărcare, deşi aparatul are un consum foarte ridicat de energie. O caracteristică profesională este punctul din meniu „Battery diagnostic” care afişează starea bateriei, numărul de expuneri (de la ultima încărcare) şi durata de viaţă. Modelul mai ieftin de 10 megapixeli, D80 (870 euro), seamănă la exterior cu modelele D70, însă atinge nivelul lui D200 la calitatea imaginii: 57/55 puncte la ISO 100/400. Senzorul de 23,6 x 15,8 mm produce fotografii de 32,78 x 21,95 cm la 300 dpi, care nu sunt salvate pe carduri CF ca şi la D200, ci pe SD. A fost preluat de la D200 modulul AF Multi-CAM 1000, cu 11 puncte de măsurare. Spre deosebire de D200, la D80 avem mai puţine posibilităţi de influenţare a focalizării automate – de exemplu, selectarea manuală a grupelor de câmpuri de măsurare. În plus, lipsesc diferite rotiţe care la D200 permit accesul direct la diferite moduri de AF sau metode de măsurare a expunerii.Display-ul LCD (iluminat) este mult mai mic decât la D200, iar pentru a compensa acest lucru, nu s-a recurs la reducerea numărului de informaţii, ci s-au micşorat cifrele şi simbolurile. Display-ul TFT este la fel de mare ca la D200, 2,5 inchi, fiind mai mare decât la D50/D70s. Şi la D80 avem acelaşi factor de magnificare a vizorului de 0,6; imaginea din vizor este astfel vizibil mai mare decât cea a multor aparate concurente. Dacă nu vă simţiţi confortabil cu numeroasele opţiuni tipice pentru Nikon, găsiţi în meniul lui D80 la „Menu select” opţiunea „Custom mode”. Aici aveţi acces la fiecare dintre cele cinci submeniuri şi la punctele de meniu aferente. Fiecare punct de meniu poate fi activat sau dezactivat, obţinând astfel un meniu personalizat. Spre deosebire de D200, aici lipseşte meniul „Last settings”. La D80 pot fi prelucrate imaginile deja expuse şi salvate ca noi fişiere. Printre opţiunile de prelucrare se numără corecţia „ochi roşii”, efectele monocromatice (alb-negru, sepia sau tonul albastru), precum şi filtre cum ar fi Skylight sau Warming tone. La balansul de culoare puteţi modifica atmosfera de culoare cu ajutorul unui meniu grafic pe patru axe. Suplimentar, e posibilă decuparea unor porţiuni din imagine sau generarea de imagini micşorate, pentru trimiterea lor prin e-mail. La „Image cut” se pot contopi două imagini RAW într-o dublă expunere. Cu „D-Lighting” se poate efectua reglarea contrastului în trei trepte – zonele de umbră sunt iluminate şi aduse la nivelul luminilor din imagine.

Aparate foto profesionale: D2Xs şi D2Hs
Clasa profesională se defineşte la Nikon nu neapărat prin rezoluţie, ci prin tipul carcasei, identică la modelele D2Xs şi D2Hs, dotate cu grip şi etanşeizate contra prafului şi umezelii. Tipic e şi display-ul TFT de 2,5 inchi, precum şi display-ul LCD care-l completează pe primul şi e dispus în partea superioară a carcasei. Toate elementele de control, cele patru rotiţe, precum şi diversele taste sunt dispuse ergonomic şi permit utilizarea aparatului foto fără a fi nevoie să se recurgă la manual. Altă trăsătură comună: ambele modele utilizează un CMOS pentru compunerea imaginii, şi nu un senzor RGB ca la celelalte SLR-uri digitale din aceeaşi casă. La balansul de alb, aparatele foto lucrează cu trei sisteme de măsurare: un senzor la prismă măsoară temperatura culorii, independent de culorile subiectului (măsurarea luminozităţii), influenţând astfel valorile furnizate de senzorul de imagine şi de măsurarea în matrice 3D, şi în cazul expunerilor cu bliţ. Printr-un emiţător care se montează pe podeaua carcasei, este posibilă transmisia imaginilor de la aparatul foto la o reţea locală (LAN). Cu o rezoluţie nominală de 4 megapixeli, D2Hs (3.100 euro) face o impresie exotică printre celelalte aparate SLR din categoria profesională. Din această cauză, valorile calităţii imaginii se situează cu mult sub nivelul standardului clasei (45,5/43,5 puncte la ISO 100/400). Aparatul foto pentru reportaje e conceput pentru viteză, reuşind să capteze 6,5 cadre pe secundă, putând salva mai mult de 50 de imagini într-o serie. Modelul de top de la Nikon, D2Xs (4.400 euro), reuşeşte să atingă cu un senzor APS-C (23,7 x 15,7 mm) o rezoluţie de 12 megapixeli şi să obţină 62 puncte la calitatea imaginii la ISO 100 /59,5 puncte la ISO 400). La nivelul de zgomot de imagine, D2Xs şi D2Hs ating valori asemănătoare, iar la fidelitatea de culoare şi la contrastul de obiect D2Xs reuşeşte din nou să se distanţeze. Modulul AF lucrează la fel ca la D2Hs cu 11 puncte de măsurare şi nouă senzori în cruce. Întârzierea de declanşare inclusiv timpul de AF este de 0,22, net mai scurt decât la celelalte modele de la Nikon. În modul highspeed, aparatul foto foloseşte o zonă centrală din imagine la o rezoluţie de 6,8 megapixeli; un complex raster electronic uşurează compoziţia fotografiei. Astfel, rata imaginilor se măreşte, conform producătorului, până la opt cadre pe secundă, dar să nu uităm că aparatul reuşeşte şi la rezoluţie maximă până la 5,2 cadre pe secundă şi 20 de imagini într-o rafală.

Accesorii pentru aparatele foto
Un Nikon vine rareori singur: numeroasele accesorii uşurează şi extind posibilităţile aparatului de fotografiat. Astfel e, de exemplu, gripul multifuncţional pentru D200, MB-D200, care poate fi dotat la alegere cu unul sau doi acumulatori Li-Ion de tipul EN-EL3e sau cu şase baterii mignon (alcaline, Li sau Ni-MH). Pentru sporirea confortului în timpul manevrării, acesta e dotat şi cu un declanşator pentru formatul tip portret, două rotiţe de reglare şi o tastă separată AF-on. Asemănător cu acesta e şi grip-ul MB-D80 pentru Nikon D80. Adaptorul WLAN pentru transmisia imaginilor spre o reţea wireless este destinat atât seriei D2 (WT-2/2A), cât şi lui D200 (WT-3/3A). În completare, mai există antena externă WA-E1 pentru extinderea razei de semnal wireless de la 30 m la 150 m, în aer liber. O altă combinaţie ar fi un aparat foto Nikon cu un receptor GPS pentru sistemul de poziţionare globală. Receptorul GPS poate fi cuplat la un sistem Garmin sau Magellan, iar coordonatele geografice împreună cu timpul global (WTC) pot fi integrate în metadatele unui fişier imagine. Astfel, un fotograf care face fotografii în deşert poate regăsi oricând locul unei expuneri care i-a plăcut în mod deosebit cu ani în urmă. Jurnaliştilor le este uşurată munca prin funcţia GPS în cazul unor evenimente catastrofale, cum ar fi inundaţiile, în acest caz reuşindu-se identificarea poziţiei din elicopter. Pentru conectarea la GPS se foloseşte cablul adaptor MC-35. Un teledeclanşator cu cablu precum MC-30 (pentru D2/D200) permite declanşarea fără miscarea involuntară a aparatului şi dispune de o funcţie de reglare a timpilor de expunere mai lungi; MC-36 permite suplimentar expunerea la anumite intervale şi dispune de un display iluminat. Şi mai confortabil: cu ajutorul telecomenzii Modulite ML-3, aparatele foto de tipul D2/D200 pot fi controlate de la distanţă prin două canale infraroşu separate; distanţa maximă de utilizare e de 8 m. Vizorul unui aparat digital SLR de la Nikon poate fi modificat în diferite moduri – de exemplu, se poate ataşa un vizor angular, care uşurează expunerile de la nivelul solului. Oferta constă din DR-5 pentru aparate cu ocular rotund (seria D2) sau DR-7 pentru aparatele cu oculare dreptunghiulare (D200, D80, D40 sau D50). Lupa de mărire (DG-2) permite la majoritatea aparatelor din seria D o mărire 2x a subiectului de fotografiat, din mijlocul cadrului. Plăci mate cu raster există doar pentru seria D2. La aparatele pentru amatori, D80 sau la semiprofesionalul D200 se poate activa un raster în vizor – o funcţie foarte practică pentru fotografia de natură statică sau arhitecturală, când aparatul trebuie să fie poziţionat perfect la orizontală.

Serii de obiective pentru Nikon
Familia de obiective de la Nikon este foarte diversificată, o privire de ansamblu fiind destul de complicată, chiar şi pentru cunoscători. Obiectivele din casa Nikon se numesc deja din 1932 „Nikkore”. Prin Nikon F, Nikon a introdus în 1959 baioneta F, care a fost dezvoltată simţitor în decursul timpului, adăugându-i-se numeroase contacte electronice, însă ca dimensiuni a rămas neschimbată. La început, obiectivele erau cuplate printr-un adaptor sub formă de cablu pe inelul diafragmei, dar care a devenit de prisos odată cu introducerea filetului AI. Acronimul AI vine de la „Automatic Maximum Aperture Indexing” şi face conexiunea directă între obiectiv şi carcasa aparatului foto. Multe - însă nu toate - obiective de la Nikon au putut fi modificate pentru noul filet AI. Cele mai multe obiective AI pot fi utilizate şi în prezent la aparatele foto moderne de la Nikon, fapt ce i-a conferit baionetei F durabilitatea în timp. Normal că în acest caz ne lipsim de focalizarea automată, dar aceasta poate fi făcută manual, cu ajutorul inelului de focalizare de pe obiectiv. Compatibilitatea acestor obiective e însă şi mai mult relativizată, dacă ne gândim la câte alte funcţii ar trebui să se renunţe. De exemplu, un obiectiv AI funcţionează la un F100 şi F6 sau la aparatele profesionale D1/D2 cu programele prioritate de timp şi măsurare ulterioară, însă nu şi cu programele prioritate de diafragmă sau de program. La toate aparatele foto din clasa sub 1.000 euro, de la D40 până la D80, prin folosirea unui obiectiv AI Nikkor cade complet măsurarea expunerii, deoarece acestea nu au modulele necesare măsurării deschiderii diafragmei. O excepţie lăudabilă o constituie D200: pentru a utiliza un Nikkor AI cu focalizare manuală, trebuie doar să introduceţi în meniul aferent deschiderea minimă a diafragmei şi distanţa focală – foarte practic pentru posesorii de obiective Nikkor vechi, a căror calitate mecanică şi optică rămâne încă şi în ziua de astăzi aproape imbatabilă. La începutul anilor '80, montura AI a fost transformată în AI-S, cam odată cu apariţia lui Nikon FA: pentru ca aparatul foto să poată efectua fotografii clare la programele prioritate de diafragmă sau de program, procesorul intern avea nevoie de informaţii despre distanţa focală a obiectivului. Dat fiind că obişnuitele obiective AI nu fuseseră proiectate pentru aceasta, toate obiectivele Nikon au fost dotate din acest moment cu montura AI-S. Obiectivele de acest tip se recunosc după culoarea portocalie a deschiderii minime a diafragmei şi după o uşoară protuberanţă pe baionetă. Şi F-301, F-501 sau F4 au nevoie de obiective AI-S pentru a putea funcţiona optim. Obiectivele cu focalizare automată introduse în 1986, odată cu F-501, corespund mecanic monturii Nikkor AI-S. Pentru focalizarea automată e activat un motor din obiectiv, care e cuplat la un mecanism de transmisie spre inelul de focalizare. O altă noutate este microprocesorul integrat, denumit şi Central Processing Unit sau CPU. Obiectivele AF cu CPU suportă toate funcţiile aparatelor SLR digitale şi analoge actuale de la Nikon, cum ar fi măsurarea în matrice 3D şi sistemul de măsurare 3D cu multi-senzor, ambele necesitând informaţii despre distanţă, de la obiectiv. Toate obiectivele Nikkor D posedă această caracteristică, la fel şi cele de tipul G. Ultimele se deosebesc de tipul D prin lipsa inelului de diafragmă; diafragma este în acest caz controlată numai cu ajutorul aparatului foto. Din 1996, Nikon produce obiective Nikkor AF-S, cu motor ultrasonic încorporat (Silent Wave). Dezvoltarea acestei linii de produse a durat însă ceva mai mult decât la concurentul principal, Canon. Obiectivele precedente erau Nikkor AF-I, care dispuneau la fel de un motor de focalizare (însă nu Silent Wave). Cei mai noi membri ai familiei de obiective de la Nikon sunt obiectivele DX, special concepute pentru senzori digitali de format APS-C. Şapte din opt obiective din această serie sunt de tipul Zoom şi AF-S, cel de-al optulea fiind un Fisheye Nikkor 2,8/10,5 mm G ED DX, care poate să se descurce fără motorul de focalizare datorită distanţei de focalizare foarte mici. Un alt avantaj este că la obiectivele AF-S, focalizarea automată funcţionează prin rotirea inelului de focalizare, făcând astfel posibilă continuarea focalizării în mod manual (mod de funcţionare M/A). În programul de obiective de la Nikon se numără în prezent aproximativ 40 de obiective cu focalizare automată. Pe lângă modelele DX amintite, se mai găsesc cam o duzină de alte zoom-uri de tip AF-S, la care se adaugă 20 de obiective fixe, de la fisheye până la super-teleobiective cu distanţă focală de 600 mm, precum şi trei teleconvertoare. Pentru apropiere, Nikon are patru Micro-Nikkor în program, cu 60 mm, 85 mm, 106 mm şi 200 mm. Un „must have” pentru fanaticii calităţii este Micro Nikkor 2,8/60 mm D AF – unul dintre cele mai bune obiective Nikon, fiind interesant atât pentru apropiere cât şi pentru portrete, corespunzând unui factor de unghi vizual de 1,5 la o distanţă focală de 90 mm la fotografia analogă. Micro Nikkor 85 mm este un aşa-numit „obiectiv PC”, denumire care nu are nimic de a face cu calculatoarele, ci cu posibilitatea de control a perspectivei, prin deplasarea axei optice. Se mai găsesc încă în comerţ obiective cu focalizare manuală, cu distanţe focale cuprinse între 20 şi 105 mm. Printre obiectivele cu distanţă focală variabilă din seria DX, se remarcă 2,8/17-55 mm G ED-IF AF-S DX; optica de înaltă calitate se îmbină cu o luminozitate de 1:2,8, făcându-l astfel recomandat pentru toate aparatele foto SLR Nikon digitale, singurul cusur al său fiind însă preţul foarte piperat, 1.400 euro. Bun şi în acelaşi timp rentabil este însă teleobiectivul AF-S Zoom Nikkor 4,5-5,6/70-300 mm G VR, la care iniţialele VR (Vibration Reduction) înseamnă că obiectivul e dotat cu un stabilizator de imagine. O listă cu obiectivele Nikkor o veţi găsi la secţiunea de tabele; cele mai multe dintre ele au fost caracterizate prin „recomandate pentru digital” pentru cel puţin un aparat de la Nikon.

Bliţuri cu i-TTL
În oferta Nikon există în prezent trei bliţuri de sistem, completate de un sistem macro-bliţ (vezi caseta). Capul de serie e SB-800, cu un număr-ghid 38 (ISO 100 la 35 mm), care are întreaga gamă de funcţionalităţi a unui bliţ extern profesional. Suportă standardul flash de la Nikon – CLS (Creative Lighting System), al cărui nucleu îl constituie controlul i-TTL. Acesta funcţionează la fel ca D-TTL cu măsurătoare a bliţului înainte de expunere, însă are în plus posibilităţi suplimentare, printre care se numără controlul prin infraroşii. Astfel, un SB-800 poate fi declanşat şi prin bliţul încorporat al unui SLR digital de la Nikon în modul master-slave. Cu tehnologia i-TTL sunt compatibile toate aparatele foto SLR digitale actuale de la Nikon; e necesar însă un obiectiv cu CPU. D100 şi modelele din seria D1 sunt compatibile cu SB-800 prin D-TTL; cu aparatele analoge, bliţul poate fi utilizat în modul TTL. În modul de funcţionare AA (automatic), bliţul stabileşte singur iluminarea corectă cu ajutorul senzorilor proprii şi a luminii reflectate de obiect. La aparatele compatibile CLS cu obiective cu CPU, sensibilitatea, corecţia expunerii, diafragma şi distanţa focală sunt transmise spre bliţ; la alte aparate foto se compară diafragma de lucru între aparatul foto şi bliţ în mod manual (modul A). La controlul manual (M) se poate varia puterea de iluminare al bliţului între 1/1 şi 1/128 în trepte de o treime de diafragmă. Pentru controlul lui SB-800 este folosit, pe lângă tasta cu modurile de funcţionare (mode), un foarte practic navikey cu patru căi şi tastă centrală multifuncţională (SEL). O caracteristică a calităţii aparatelor de la Nikon este piciorul bliţului din metal, precum şi maneta de armare în loc de butonul obişnuit, de la alte bliţuri. În pachet se mai află un softbox şi un mini-reflector care reflectă lumina pentru iluminarea indirectă, generând astfel sclipiri în ochii persoanei folosite ca subiect într-un portret. Pe lângă SB-800, Nikon mai are în ofertă alte două bliţuri: SB-600 cu un număr-ghid 30 (ISO 100, la 35 mm), bine dotat şi o alternativă rentabilă la modelul de vârf. Mulţumită integrării sistemului CLS pot fi utilizate mai multe SB-600 într-un conector multi-bliţ şi controlate cu ajutorul unui bliţ master SB-800. Şi în acest caz, controlul poate fi preluat de bliţul integrat în aparatul foto. În final, SB-400: extrem de compact, cu numărul-ghid 21 (ISO 100, pe 35 mm), un ajutor probat pentru cazurile în care bliţul aparatului foto nu este îndeajuns sau apare dorinţa unei iluminări indirecte (reflectorul poate fi rabatat) – o completare foarte bună la compactul D40.

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technorati tags:photography, digital, nikon

10 Tips for Street Photographers

By Kyle Hepp

9 August 2007

1. Be discreet. If you are trying to capture the moment without your subject's active participation in the photo try to not to make a big deal about taking your camera out or changing your lens. You want to blend in with your surroundings, not scream to the world, "I'm a tourist, I'm a tourist!" I'm a blonde girl living in a city (Santiago) full of dark haired vixens. I wear a hat and dark, nondescript clothes to try to blend in because if I don't, too many people approach me to try and practice their English and they distract me from the shots I want to take.

2. If you can't be discreet, ask permission. I once picked up my lens to shoot a street vendor selling peanuts and as I looked through the viewfinder, I realized he was staring right at me and scowling. I was pretty far away from where he was standing but he had noticed that I wanted to take his picture. As soon as I pointed at my camera, pointed at him, and made shrugging gestures indicating I wanted to photograph him, he nodded, immediately relaxed and I got a fantastic shot.

3. Street photography is often described as "gritty," so try to capture the grit! There's no sense in only photographing the beautiful part of a city. I'm not saying you need to go someplace dangerous but I am saying that you should get out of your comfort zone. I have learned that shooting in places that I'm not familiar with is the best way to get good shots. If you are in a place that has been photographed by many other people it's too easy to take a cliché photo that has been done a thousand times before.

4. Pay close attention to the details around you. Some of my best photos have been when I've really paid attention to the minutia of a city, such as it's graffiti, trash, street signs or the way people walk. Include these things in your composition and you can make the photo much more interesting. I have learned to love photographs of feet that show the rhythms and movement of a city. One of my favorite photographs I shot of nothing more than the patterns of the sidewalk.

5. Don't be afraid to try photography techniques that are out of the ordinary. I took a shot of a kid sitting in front of a wall covered in graffiti and put him in the left third of the photo following the rule of thirds. The shot was boring. When I centered him, the image was transformed into something much more powerful and direct. Sure, it's not a composition from the text books, but I think the picture turned out so much better that way.

6. Be aware of your surroundings. So many photographers completely lose themselves in the moment when they get behind the camera. This isn't safe. Either go out shooting with a partner, someone who will have your back the whole time you're not paying attention because you're shooting (and vice versa), or put down the camera every 30 seconds and take stock of what, and who is near you. Trust me. I know from sad experience that it takes less than 5 seconds for someone to cut your camera strap and dash away with your most prized possession.

7. Know your rights. In the country you're in are you allowed to shoot in public places? If so, then shoot away and if anyone tries to tell you that you can't, simply state that you are acting within the boundaries of the law and they cannot stop you. Once, a policeman was trying to get me to stop photographing a car crash. He screamed and yelled and tried to intimidate me, but as soon as I mentioned that I was well aware that what I was doing was lawful and that he wasn't legally able to stop me, he shut right up and let me continue shooting.

8. Don't discard a photo because it doesn't meet your normal criteria. Criteria for street photography should be different than the standards you normally hold yourself to for studio photography, or posed portraits, for example. I once almost discarded a photo because instead of getting the focus right on the subject, I had focused on a tool in his hands. When a friend looking at the photo said, "It's so awesome that you are focusing on his work to show that it defines him," I knew that my accidental focus made the shot interesting. I'm not saying you should lower your standards and take poor quality photos. The point I'm trying to get across is that when you are taking street photos, you have less time and the conditions are often less than adequate. Those little "mistakes," you make, like an odd focal point, low lighting and too much grain, or a strange perspective, are what can make a street photo a thousand times more intriguing than a perfectly posed and lighted studio shot.

9. Define what you are trying to capture: person, place or thing. Are you trying to portray the seediness of a nightclub? That's a place, so stay right near the night club and photograph the area from a thousand different perspectives until you get perfectly capture the mood. Or are you trying to perfectly capture an animal subject? Then follow it. I have seen a thousand photos of a dog lying in the streets, or in doorways. But, the most interesting set of pictures of a canine that I ever saw were from a photographer who trailed a dog for a half day taking pictures of the dog's life scrounging for food, flirting with girl dogs, marking his territory, and fighting with other street dogs. He got down and shot from the dog's perspective too, and the end result was fascinating. Animals can be so one-dimensional if you only shoot them in one setting doing one thing. The same goes for people. If you have decided the focus of your street photography is a person, I would try to capture them interacting with their environment in as many different ways as possible, and showing multiple emotions so you can portray them in a multi-dimensional way. Just a word of caution, always ask before you start following a person around or they may think you're a stalker!

10. Lighten up. The people you are taking pictures of aren't paid clients. They aren't going to freak out if you don't photograph them from their best angle. Relax, go out and enjoy the experience. Don't put pressure on yourself to come back with a million awesome photos. Since you can't control lighting, posing, crowds, or a million other factors, you need to be able to go with the flow. I have a handful of about 10 great street photos that are the result of more than 10 trips into the city. Getting that perfect shot is not easy, so don't stress!

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technorati tags:photography, street, tips

Ten Tips To Wedding Photography

By Langley Windy

9 August 2007

If your already a wedding photographer you will already know what I am about to say, but if your new to the big world of wedding photography you will need to read these " Ten Tips To Wedding Photography".

Wedding photography is a very keep you on your toe's job and it is not for the shy hearted person at all you must be fast out going and aggressive to get your job done all to stay a top of your game. If you follower the steps you will be on your way to becoming a wedding photographer the tips are as listed.

1) Make sure the type of photography the bride is wanting is something you can do and do well.

2) All agreements should be clean and on paper so you will not end up with no misunderstanding between you and the bride to be.

3) It is good to either already know the location of the wedding or make it a point to go take a look so on the day of the wedding you will know just where you want to get all those prize photos in at.

4) Make sure the bride has some one to appoint to be over the wedding party both sides bride and groom, this is to help you do your job better.

5) Learn how to run the show on the part of the photography or you will find you will be over stepped and you will not get the photos you was paid to get.

6) Make it a point to have the wedding party come to the location of the wedding at least two hours before the wedding to take all the before photos this will save time after the wedding and you will find you will be able to take better and more fun photos.

7) In today's world you may suggest that the bride and groom take their photos a long with the ones you will be getting before the wedding but let it be known if they do not want to do this step number six still needs to be done.

8) With all the before photos done now you have time for family photos after the wedding and bride and groom with everyone in the party if you was not able to get this before the wedding. This should be done in a timely manner they do have guest waiting.

9) Always make sure the bride knows not to let any special moment happen with out you and your camera there.

10) Last but no least HAVE FUN!!!!

If you keep all these steps in mind you will find you will be more in control and it will make you a better photographer for doing so and your photos will show it and along with that comes more jobs.

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technorati tags:photography, wedding

Infared and Time on Your Hands

By Patrick Fulks

2 August 2007

I had purchased an infrared filter for my Nikon D200 and of course had to take it out and play with it. The initial images that I got were ok but I wanted to do something a little different from the average shots of trees and grass that usually come out white with a infrared filter versus darker tones in a standard black and white. I wanted to get creative.

So I contacted a model that I regularly work with and we got to work. We decided that the eerie effect that an infrared filter can give was perfect for cemeteries (which you will find infrared of gravestones and such on several sites on the internet) but to be creative we decided to work with the multiple exposure feature of the D200. We were going to create a duplicate of my model and make her visit her ghost self in front of a grave marker.

To do this I had to first set my camera for shooting in black and white. If you leave your camera set to shoot in color you will get nothing but a red image. This is caused by the infrared filter does not allow for any visible light to get through. Only light from the upper spectrum (above 720mm) passes to your sensor.

Next I had to set the camera for four exposures of the image. I set the ISO at 100, f3.8 and exposure at 125 The first three of the four exposures I set for 8 seconds each. The reasoning behind why I did three exposures of the exact same thing would be to make the model appear solid. I had the model stand next to the grave marker and place her hand approximately 1.5 inches above the top of the marker. Now here comes the hard part. She had to remain perfectly still for each of the first three exposures and not even blink. If you want to get an idea of how difficult this is stand up and hold your arm out, don't move a muscle or blink for 24 seconds. It's tougher than it looks. (got to give the model her due!) We took the first three exposures and had her move to the other side of the marker, kneel on the ground and place her hand on the top of the marker to give the appearance of her hand being under where the hand was placed in the first three exposures.

I set the camera for 15 seconds on the last exposure to get enough light in to make her visible over the first three exposures.

The blur effect of the models dress when standing was caused by the slight wind that was blowing that day and you can see this in the leaves of the trees in the background. It is highly recommended that if you are going to do prolonged exposures of more than a couple seconds that you try this on a day where there is very little or no wind to get a crisp clean image. Personally I like the effect, and feel that it adds to the overall eerie feel of this picture.

I do want to note that the settings of my camera are strictly what I used for this shot and are not a standard by any means. It will vary depending on time of day, and if it's overcast or direct sunlight. Play with these settings to get the desired effect. To do this you will not be able to see through the viewfinder of your camera as I stated before, the infrared filter does not let any visible light through. You will have to basically aim the lens and shoot. Then check your image and adjust to frame out your shot. I can't imagine how difficult this must have been before digital cameras were commonplace and trying to frame a shot with film.

Should you decide to try infrared photography I wish you luck and happy shooting!

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technorati tags:photography, infrared, digital, filter