Nikon D5100 Experience Manual page 50

Nikon D5100 Experience
Playback Menu. These two views will show you a tiny version of your image, plus the
histogram and various camera settings (see Figure 32). If you need to view your image larger,
you can zoom in with the Magnify Button, then zoom back out to the detailed view.
Figure 32 – Overview view of image playback, showing histogram
The histogram is the little graph that shows peaks and valleys which represent the distribution of
an image's brightness levels (the RGB histograms show distributions of specific colors). The
histogram of an image with lots of dark areas will have peaks at the left side of the graph, and an
image with lots of light areas will have peaks at the right side of the graph. A typical image may
show a distribution of peaks across the entire graph, or maybe a nicely centered "mountain."
But, the histogram of an ideal image does not necessarily show a nice distribution or a well
formed "mountain." If you are taking interesting images with dramatic lights and darks, the
peaks may be all over the graph. This is fine. The key to proper exposure, however, is to make
sure that the peaks drop down to zero, the base of the graph, before they reach the left and right
edges. If your peaks run off the sides of the chart or spike at the far left or right sides, that means
you have blown-out the darks or lights, and those areas of your image will be pure black or pure
white, with no detail remaining.
The darks are on the left side of the graph, and the lights are on the right side. (This is one
reason why I find the default Exposure Indicator direction to be backwards and counter-intuitive
– it does not match the (-) and (+) direction of the histogram. Remember you can use Custom
Setting f5 to reverse direction of the Exposure Indicator.) It is especially critical that you don't
blow-out your highlights, the whites, on the right side of the graph. Review your images'
histograms to make sure that the peaks fall down to zero at or before the right side of the graph.
When you view your images on the rear LCD Monitor in Highlights view, the blinking
highlights indicate the areas of the image that have no detail, where your histogram peak has run
off the right side of the chart.
Now there may be exceptions to this practice. The camera sensor has a limited dynamic range
compared to your eyes, and cannot capture the full visible range of dark to light. That means
sometimes you have to sacrifice the details in the shadows in order to retain the details in the
highlights – meaning the peaks will have to run off the left side of the graph in order for them to
not run off the right side of the graph. Or other times you may wish to blow-out some highlight
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