In article <1193733169.993827.142570@[EMAIL PROTECTED]
>,
The Translucent Amoebae <transamoebae@[EMAIL PROTECTED]
> wrote:
> i think about them this way...
> Brightness seems to increase/decrease the whiteness of all pixels
> uniformly
> Contrast seems to make dark pixels darker, and light pixels lighter
> Exposure is more complicated;
> When you lighten a picture, the light pixels get lighter, but the dark
> pixels remain pretty much the same darkness. This occurs along a
> curve, so the dark pixels are effected, but not by as much.
> likewise, when you darken a picture with Exposure, the dark pixels get
> darker, and the light pixels remain pretty much the same.
>
> i do use the Levels controls, and i've noticed that when the spikes
> are clumped together in the middle, and i slide the dark or light
> towards the mountains, it seems to bring out detail by enhancing
> surface texture with local contrast...???
>
> But i STILL don't SEE what the mountains are supposed to be
> representing...
> Obviously; it's a graph of somekind, and as such, the x & y axis must
> represent SOMETHING...???
> But i just don't see what...???
I just googled for "digital photo histogram" and the first hit was
http://www.photoxels.com/tutorial_histogram.html
which does a good job
of explaining what the histogram means.
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