Filter
Top Products
Histograms are a way to measure exposure more objectively for those who can't see very
well. Histograms don't replace your eyes and experience. Histograms are helpful in
sunlight where it's hard to see an LCD, or in the shop if setting something exactly. Your
eyes are always the final judge.
A histogram is just a guide. Worry about your image more than the histogram.
HISTOGRAM BASICS
A histogram is a graph counting how many pixels are at each level between black and
white.
Black is on the left. White is on the right.
The height of the graph at each point depends on how many pixels are that bright.
Lighter images move the graph to the right. Darker ones move it to the left. Easy!
More Pixels
Fewer Pixels
Black - Dark - Medium - Light - White
A Histogram
A good image often, but not always, has a histogram spread all over.
HISTOGRAM HISTORY
Histograms are rocket science. Histograms have been used for automated image
evaluation and optimization in self guided missiles for decades. When Tomahawk missiles
share America's freedom with millimeter precision, you can thank histograms. Raytheon
calls this "Digital Scene Matching Area Correlation," or DSMAC. This all used to be
classified.
You are smarter than a histogram. Use them as guides, not Gods.
COLOR HISTOGRAMS
Color histograms (page 83) are required for color digital photography. Many cameras lack
these. I cover this later (page 83). If your camera only has a single histogram, like the
Nikon D70s, D1X or Canon 20D, ignore the histogram! Single histograms are dangerously
© 2007 KenRockwell.com 80 converted by Sándor Nagy