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Digital Photography
THE BASICS
Exposure
We talked about white balance and it being a major part of the digital battle.
The other part of this important battle is exposure. Once you've got color
balance and exposure down pat, you've got it made in the digital shade. 99.99%
of all you need for a great image is done!!!
Okay, so in order to get perfect, or near perfect exposure, you need a standard,
old-fashioned 18% grey card. Get your light meter out and load your favorite
lens on your digital camera. For my D1x it's a 50mm 1.4, my "workhorse". You
will probably want to use the lowest possible ISO that your camera is capable of
using. With the D1x it's 125. Now I set my flash meter at 125 ISO and take a
meter reading of the grey card with my main studio flash. Now I take an
exposure of the grey card at the reading the meter says, and open the image up
in photoshop.
Here's what I got on my first try, f11 at ISO 125:
As you can see, the "peak" in my histogram is to the left. However, it should be
in the middle since grey cards reflect 50%.
Okay, so I take another one at ISO 100 f11 and here's what I get:
Close. Almost in the middle. No cigar, moving on.....
Let's try it again, this time at ISO 80 at f11. Here's what that gives me:
BINGO!! Damn near perfect. The peak is just about smack-dab in the middle of
my histogram. What does all this mean? It tells me that I need to expose in a
controlled setting at ISO 80, when the camera is set at ISO 120, with that lens.
Remember, it's exposure calibration designed for controlled portrait situations
with a specific lens and camera at a specific ISO camera setting. Kinda like
rating 160 portrait film (yea, remember that stuff...) at say 100, or 80.
Good exposure and good white balance at capture. Aaaaawww, just like a
perfect cheeseburger. (A little more on that later...)
Personally, I am convinced that many photographers are petrified of over-
exposure in digital capture so they actually end up under- exposing, which is a
serious, serious no-no. You need your tones placed as close as possible in the
histogram scheme-of-things, especially to get great skin tones. Hence, your
light meter will be your best friend and most used/cherished tool, once you've
calibrated for exposure.
