Exposure problems - Nikon D100 (1 Viewer)

Please can someone offer me some constructive advice. I recently invested in an Nikon D100 and really appreciate al lit gives in terms of speed etc. However, a problem seems to be that although the images in the LCD screen on the camera appear perfectly exposed, when I come to see them on my PC they appear generally underexposed, and I have to 'tweak' them with Adobe Photoshop.

Surely this should not happen? I can't think it's my PC because I also have a Coolpix 4500 and use it regularly for digiscoping and hardly ever have to tweak the image on the PC.

I tend to shoot with the Programme setting on the D100, with varying ISO settings dependent on prevailing light conditions. I also shoot with either matrix or centre weighted metering and use 'mode' III for wildlife shots.

All comments gratefully received

Birder it may not be the answer to your problem, but just check that you havn't mistakenly dialled in some compensation. It very easy to do this with the D100 and not realise its set in there.

Hi Birder,
The D100 does underexpose to prevent the whites from burning out. All digital cameras have an exposure latitude problem (even less latitude than slides) and it is very easy to overexpose the highlights with these cameras. There are custom curves which you can download for free from the web and feed into your camera to rectify this problem. I prefer Photoshop. Hope that helps.
Sumit

Birder
Ihad trouble getting used to my canon 10D for same reason. I sterted using the histogram and also watching the highlghts at same time and found I had better success than depending on the picture display alone. A tip I picked up on luminouslandscape.com, is to keep info on histogram to the right as much possible without touching edge. Good tutorial stuff on that site.
Joe

Here is my 2 cts worth. My first suggestion is to move away from Program mode and shoot Aperture Priority. The second suggestion is to use Center-weighted Metering rather than Matrix as matrix tends to overexpose. If you are consistently getting overexposed photos, set your camera to EV-0.3 to EV-0.7 and leave that as your setting.

Birder: This is a topic that's constantly coming up, and I had the same "problem" when I first moved to a pro Digital SLR. The autoexposure modes on all SLR's are algorithmically based - the camera's guessing about what you consider important in the picture. The consumer-level cameras are set to give the best point-and-shoot results. In my experience, that means they don't mind blowing out highlights (such as sky). The pro SLR's are set to allow the MOST detail possible. Given the 5 or 6 stop latitude of most CCD's, this means that the pro's tend to underexpose, rather than overexpose. The reason? You can lift detail from shadow areas with a little post-processing, but once you've blown the highlights, that's it. There's nothing you can do.

I real terms, this means that you MUST be able to predict what the camera's going to do, and use exposure compensation to modify the camera's guess. Nikon's matrix metering seems very unpredictable. For that reason, I ALWAYS use centre-weighted, or occasionally spot metering. Here's an example:

You have a white gull with a dark leafy background (leafs and trees and general wooded gunk). The gull fills about 1/8 of the area in the viewfinder. The camera will try and make the average of the scene into middle grey (half-way between white and black). Because it tries to make the dark background into a lighter middle grey, it will tend to overexpose the gull. So I'd dial in -.7, to -1.3 eV. In other words, I'd underexpose. Why? Because I'd otherwise "white-out" the gull. I'd anticipage that doing this would give me a very dark background, and a gull where the whitest parts are on the extreme right of the histogram - close to being blown-out, but not quite. There'd still be detail in the whites.

You're basically thinking about the contrast between the subject and the background, and modifying the camera's guess to compensate. I generally figure out whether I think the overall scene seems lighter or darker than middle grey, and whether the subject is lighter or darker than middle grey. If they're both lighter, the camera will underexpose. If they're both darker, the camera will overexpose. If the overall's darker, and the subject's brighter, the camera will overexpose. If the overall's brigher and the subject's darker, the camera will underexpose. You then need to dial in some compensation to bring thing back to where they should be. The only time you don't need any compensation is if the overall scene averages out to middle grey.

I'd turn on the histogram and blinking blow-out review screens on your D100 as well. They're invaluable for telling whether you've got problems with the picture. The option to turn them on is in the custom settings menu somewhere.

Holy moly, that's a long message. Have I hopelessly confused things? I hope not. Arthur Morris gives a great explanation of these topics in his book "Birds as Art". It's the best book on bird photography I've ever seen, and I highly recommend it. Here's my summary of things I do to get the best possible images:

1. Centre-weighted metering
2. Think! Predict! Reshoot if necessary (and possible).
3. Use exposure compensation frequently.
4. Shoot RAW - it gives more latitude for fixing things.
5. Set your own white balance (use daylight for daylight, etc). Avoid Auto.
6. Sharpen in post-processing, not in-camera.
7. I use Mode III, but that's personal preference.
8. Practice, practice, practice.
9. Don't sweat it if you don't get the shot. Another one will come along eventually. Have fun, don't consider it "work".

PS. Another thing to watch is that when you're viewing full-size images on-screen, they're likely to appear darker than they really are, just because they're often scaled down to fit on the screen - dark pixels tend to overpower light ones on the screen. Try viewing them at 100% and you might find that the exposure's not as bad as you thought. 'Course if you're going to use them on the screen, you might want to lighten them up a bit in post after scaling them down.

This goes a long way to explain my problems; I rarely made a wrong exposure with my film camera. I normally check the overall lighting with a light meter; it's only a starting point but can give you a clue as to where the exposure is going. My problem is with macro or distant subjects and your advice should help me in this.

This thread addresses a problem which is really a sort of Achilles' heel of digital photography to this point. Digital cameras just don't deal with high contrast situations all that well, and whites tend to be "blown" all too easily. This makes photographing many birds more challenging than one might expect.

The problem with trying to address this phenomenon only in post-processing is that once the white tones are blown out they cannot be rescued (i.e., there is no information that can be manipulated).

I find that to prevent the blowout of whites in bird photos, especially when the sun is shining on their plumage, I have to underexposure well over one full stop, and sometimes two stops or more. This maintains the white tones, but can lead to underexposed, and hence more noise-prone darker tones.

You can ameliorate this difficulty slightly by changing your tone setting to "less contrast," but this helps only a bit. Some people indeed have had luck using custom tonal curves. To do this you have to get and use Nikon Capture or whatever downloading/file manipulating software your camera system utilitizes.

I have read that the new Nikon DSLR, the D2x, has an innovative system that deals with lighter/whiter tones separately to help deal with this problem.