Reading Histograms
When I bought my first SLR (a Canon Digital Rebel XTi), I really didn’t understand anything about exposure. I simply took photos of things that I thought would look cool, I’d check the image on the LCD screen and, if it looked good, I moved on to my next shot. I knew enough to know that if the photo looked too bright, I needed less exposure (a smaller aperture, a faster shutter speed, or a lower ISO) or if the photo looked too dark I needed more exposure (a wider aperture, slower shutter speed, or higher ISO). But if the image on the LCD screen looked “good”, I figured there was nothing else I could do. Of course, this was a lot harder on very bright days. I would find myself trying to shade the screen as best as I could with my body or my hand, while squinting my eyes to look, ultimately getting frustrated at not being able to tell whether my shot had turned out like I had hoped. Finally, I’d get home, view the images on my computer and find out that part of the “good” image I thought I took was too underexposed or overexposed in one particular area that I didn’t notice when viewing it on the back of the camera. Now what?
I only had one of two options: Go back and re-shoot or try to fix the under/overexposure with software. It wasn’t often that I’d go and re-shoot because of one bad image (I tend to be lazy) so I’d start editing the photo. Often, this would work out OK but it bothered me that, as a new photographer, I was relying heavily on post-processing and not getting the image I wanted from the camera. What could I do?
This is where histograms come in.
Tags: exposure, histogram, tips
