“W” in Curves
Oct 4th, 2007 by Leo Geis
Some of the most potent tools in Photoshop are not very popular. Often it is because they are tremendously confusing, such as Black Point Compensation. Other times it’s because you have to hunt and peck to find their control dialogues. Yet others are positioned within their Dialogue Box in such a way that they never rise above the level of an afterthought. “W” is such a thing.
Click on the graphics for larger images.
The red arrow identifies a check box that will change your outlook on Clipping drastically. The underlined letter “W” indicates a Keyboard Shortcut (which may not be customized) for the capability.
In the following image the checkbox has been selected (by pressing “W”) and an adjustment has been made to the composite Curve to produce Clipping in the high key. Note that the Document Window has turned Black and that various colors are displayed to indicate areas of Clipping.
When the adjustments are made to produce Clipping in the low key, the Document Window turns white and Clipped areas are again indicated with contrasting colors:
The color key for those indicators is evidently an industrial secret at Adobe, but I have it on good authority that absolute Clipping produces Black or White (as appropriate to contrast with the existing background) and other colors indicate individual Channel Clipping. Incidentally, the Eyedropper & Info Window don’t test the native image-they test the actual Document Window display, so you can’t directly test the image with “W” selected.
I’m going to close this post with an extremely aggravating statement that will certainly prompt various emotional upsets: In aerial photography (as in most existing light applications) Clipping is not to be completely avoided. When you clip to White or Black in your Histogram, you’re going to end up with Paper White or Ink-Media Black anyway. Often, if you don’t Clip, you’ll be robbing your image of necessary midrange Contrast, which of course could be introduced with the midrange of the Curve, but in Curves, nothing is free. Additionally, there are ways to treat Clipped areas so that they don’t lose detail (you read that correctly) or maintain an objectionable amounts of Contrast, but they’ll have to wait for their own post. For now, just consider “Splitting the Sliders” in…wait for it…an Adjustment Layer with a Blending Mode!
Bonus Capability: “W” also works in SoftProof!
L