Tuesday, September 28, 2004

Into the darkness

Luminosity Histogram

Since my post "Washed out images - a small tonal tweak might help" to the Sharing Digital Photography Worldwide Forum, I've been spending a fair bit of time looking at, and trying to understand luminosity histograms. This one was generated by Adobe Photoshop Elements. This histogram, of the sunset photo above, is the sort of classic multi-modal heavily skewed distribution you encounter in all manner of phenomena in the natural world. In fact it is so heavily left skewed, or is it kurtosed, it might even be considered a log normal journey into darkness. (thats a joke for the statisticians, just in case any are looking in). In english,for the rest of us, it is a very dark photo, with a few interesting and colourful mid tones and a few rare bright spots. Its pretty tonally unbalanced!

So as well as the automatic fixers I've included some tonal balancing acts into my investigations below. You may have to dig down into your software to find the tonal equalization or balancing tools (that is they will probably not be under a top level menu called automatic something).

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