In earlier discussions we’ve looked at video of how to read a histogram and read why RAW files hold more information than JPEG. I’d suggest checking those entries out, if you haven’t already.
To date I’ve stressed proper camera exposure so file manipulation will be reduced in post-production (especially important when shooting JPEG). Speaking in general terms, the less an already processed file (JPG, TIFF, etc.) is manipulated, the more integrity there will be to the information contained within. We’ve seen that RAW files have greater flexibility for manipulation, allowing us …

There are lots of great reader comments on the tech article pages (the camera meter / histogram video, the battle of the bulbs shootout, studio color management, etc.). A couple of times it’s been pointed out that shooting RAW files (instead of JPEG) is advantageous for everything from color balance to exposure. This is very true. So before tackling some of those specific questions, I’d like to back up a little and show graphic illustrations of the difference between RAW and JPEG (also called JPG). Understanding this will help …

Can you always trust your camera’s light meter? The answer is all in the histogram…
(subscribers, video may be viewed on the website):

Here are some selected books on the topic of photographic exposure.

Reference photographs used in the video

normal histogram
overexposed histogram
underexposed histogram

Canon 20D on aperture priority auto / no exposure compensation

black card
gray card
white card

black/gray/white cards