Exposure Compensation

[MrGibbage]

I just discovered the exposure compensation function on my DR 300D. I read the manual on it, and even played with the auto-bracketing feature. My question is, why would you use this? With the auto-bracketed sets, the first picture was always the best. I shoot everything on AV, and most of my shots were outside landscape type shots, but I did do a few inside portrait shots. Without exception, the first shot was always the best. If you use this function, how and when do you do it?

Skip

[Curtis N]

Because the camera is stupid. It thinks is everything is 18% gray and tries to expose accordingly. It doesn't know what your subject is so it doesn't know which part of the image to expose correctly. If there are a lot of white or bright colors or backlighting in the image, it will underexpose. With dark colors or dark backgrounds, it will overexpose.

Sooner or later, you will have a situation where the first shot of the bracket is not the most correct. Exposure compensation is one of several possible ways to deal with these situations.

[wintoid]

I don't bracket, but I do use exposure compensation now. When I'm shooting at ISO1600, I've found that underexposed images can be noisy. As my 20d seems to expose to preserve the highlight data, it often underexposes (for my taste). I sometimes dial in 2/3 stop exposure compensation, which probably does blow the highlights a teeny bit, but gives me a much less noisy image.

[RTMiller]

There is a maxim that in order to help prevent data loss when capturing a picture, you should "expose for the highlights and develop for the shadows" (B. Fraser - Camera Raw). Sometimes I will use exposure compensation to push the histogram as far to the right as I can without clipping any data. This captures more data and allows you to 'develop' more detail in the shadows.

[MrGibbage]

So now this means I have to a) Learn to recognize that "Oh, this scene will confuse my camera and I need to add/subtract exposure compensation"; or b) Settle for chimping (when I'm really just checking the levels--honestly!) and run the risk of one of you guys taking a picture of me and posting it in here. *sigh*

[Curtis N]

Canon puts a histogram on the LCD screen for good reason. Use it. It's quicker and more efficient than taking three times as many shots in the hopes that a third of them will be useful.

[PhotosGuy]

Because the camera is stupid. It thinks is everything is 18% gray and tries to expose accordingly. I thought so too, Curtis, but found out that digital is different when I started to illustrate a Gray Card tutorial! Digital looks at the brightest highlight! See the unexpected results here:
Gray card: Why your meter may be lying to you! (http://photography-on-the.net/forum/showthread.php?t=54281)

I do agree with the "Because the camera is stupid." part, though! :D

[Curtis N]

Digital looks at the brightest highlight!That would explain why I always get underexposed pictures when there is even a small area of sunshine in a mostly shaded frame. The camera is even more stupid than I thought!

[DxHatchback]

ive always heard with AEB, you can layer the two images together to say have the right exposure on a car from the 1st exposure, and the right exposure on the sky from the 2nd or 3rd exposure

[tim]

So now this means I have to a) Learn to recognize that "Oh, this scene will confuse my camera and I need to add/subtract exposure compensation"; or b) Settle for chimping (when I'm really just checking the levels--honestly!) and run the risk of one of you guys taking a picture of me and posting it in here. *sigh*

That's one of the smaller things you have to learn if you want to get good at photography. What until you start using a flash, or even studio strobes.

[PhotosGuy]

ive always heard with AEB, you can layer the two images together to say have the right exposure on a car from the 1st exposure, and the right exposure on the sky from the 2nd or 3rd exposure You can do that with a "properly" exposed RAW shot, too, without having to take a 2nd shot. There are tutorials on the Post Processing Stickys.

[MrGibbage]

I read up a little on the idea of using a grey card, and it makes sense to me. But what do you do if you are ttrying to take a picture of a black cat on a black bedspread in good lighting? The grey card routine measures the light reflecting off the card, not the subject. I don't see how the grey card will help then.

Skip

[PhotosGuy]

The card gives an average reading which should give good whites & blacks.
Put the gray card near the cat & take a reading. Take a pic. See if it worked.
If the shot is too dark, open up a stop. Take a pic. See if it worked.
If the shot is too light... etc.