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Finally, Brightness and Contrast that Actually Work!
I've written before that the Brightness/Contrast control in Photoshop is evil and should not be used since it operates linearly on every selected pixel. There's just no way it can produce good results. Or at least there used to not be any way. But Photoshop CS3 changes all that.
 Increasing Brightness with any version of Photoshop prior to CS3 simply adds whatever you set the control at to every pixel in the image, shifting everything towards the right in the histogram. Likewise, decreasing brightness shifted everything equally darker. The tone of every pixel moved right or left in lock step, even when some parts of an image needed it more than others. The traditional version of Contrast adjustment was equally simplistic in how it operated, stretching or contracting contrast equally over the entire range of the histogram.
You can still do it that way in Photoshop CS3 if you want. Just check the new "Use Legacy" checkbox in the lower right-hand corner of the Brightness/Contrast dialog box and it will operate the way it always has. This box will be checked by default in the settings for any Brightness/Contrast adjustment layers created in prior versions of Photoshop. But for any new Brightness/Contrasts adjustments it will be off, which is a good thing since the "non-Legacy" method works a whole lot better.
Rather than operating equally, in a linear fashion, on all pixels in an image, the new Brightness/Contrast algorithm operates proportionally, much as Levels and Curves do. Pixels more in need of adjustment receive more of the effects of any change you make.
A simple change, but an incredibly useful one since it turns a basically useless control into one that just might have a place in image editing for some people. Levels and Curves are still better since they provide more control, but at least Brightness/Contrast won't wreck an image if you use it now. For casual image editing, it can in fact work quite well now.
South Dakota's Badlands National Park |
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An extreme brightness increase with Legacy checked leaves a washed out image with no blacks. The entire histogram has been shifted right. |
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The same brightness increase with Legacy turned off leaves a bright image, but one that still has some black. The histogram has shifted right, but is still anchored on the left end too. |
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