I posted this on my own blog a few months ago, but I thought some of you may be interested in learning a little about using the histogram to help with exposure, so I'm re-posting here.
My family went to The Bahamas over thanksgiving for my mom's 60th b-day. We were lucky enough to stay at the famous Atlantis resort, and the photography was pretty good. I must say, my kind of vacation is one where there's a camera in my hands. I only half joke that I usually don't take photos while I'm on vacation, I go on vacation to take photos. Atlantis did not disappoint.
This was an interesting shot to post-process. I originally shot this as an HDR (I bracketed three shots with different exposures to merge them later), but after processing them through my HDR software a couple times the photo just wasn't coming out. It just looked kind of unrealistic and I couldn't get the contrast that I wanted.
1/30 sec at f/11, ISO 100, 22mm
Then it dawned on me that HDR was designed to take scenes with light ranges beyond the ability of a camera sensor to capture and then merge them into one shot. Well, interestingly enough, all the light in one of my exposures actually fit in my cameras sensor range so no parts of the image were overexposed or underexposed. I realized this when I looked at the histogram for this shot. The left side of the histogram represents the dark tones starting at black and represents brighter tones to the right, so the big bump kind of in the middle means that most of the light was about medium brightness. You can see that the range of light in my shot just barely fit my camera sensor's range. If there were completely under or overexposed pixels, you would see tones piled up on the far left or right of the histogram respectively. Achieving this wide range of light in one shot is one of the keys to getting a good exposure, and I did it rather accidentally. So instead of trying to process an HDR, I just took the original shot as is and I think it looks pretty good. I just enhanced a few things in Adobe Lightroom like contrast and sharpness and I also photoshopped out some distracting buoys in the foreground. That's not cheating right?
Here are a few more shots from the trip.
HDR: 1/250, 1/60, 1/15 sec at f/11, ISO 100, 10mm
1/15 sec at f/3.5, ISO 800, 10mm
1/25 sec at f/4, ISO 1600, 15mm
