Idaho Airships, Inc.

Photoshop CS4 is a substantially more mature product than its predecessors. One of the most clever and promising new features is the Curves On-Image Adjustment Tool.

This post is dedicated to my friend IG Holmes, a Texan to the core who passed away Wednesday while on his morning walk. IG was an aerial photographer for over 60 years.

The context for my explanation is that I use Wacom tablets on both my workstation and laptop-they are set up for right-handed operation, and my (customized) keyboard shortcuts are weighted on the left side so that my hands don’t cross. I batch process in Actions for most of my aerial work, and I’m on a PC in PSCS4 Extended.

While the Curves On-Image Adjustment Tool is available in both the Image>Adjustments>Curves (Ctl-M) and the Adjustment Layers Dialogue Boxes, the only place you’ll ever see it (as a professional aerial photographer) is the Adjustment Layer Dialogue Box. Isn’t that right?

One of Curvemeister‘s big advantages over the pre-CS4 Photoshop Curves Dialogue Box was the display of underlying pixel luminance on the Curves display. While the On-Image Adjustment feature is selected (see the red arrow in the graphic above) and the Cursor is held over the image, the luminance value of underlying pixels is indicated on the Curve (not shown on this graphic). The effect is active on individual Channel Curves as well.

Once you click on the image, the Parametric Curve is adjusted at the luminance level sampled by the cursor. That sample size is, as you would expect, controlled by the Options for your Toolbox’s Eyedropper Tool.

To top it all off these capabilities can be automated. However, the only way I’ve been able to invoke the Eyedropper Tool and resize it in Actions is by establishing Tool Presets for it, and I’ve tried it in both WXP and Vista-if you have different results, please let me know!

On-Image Curves adjustments, as one would expect, work during Softproof (Ctl-Y by default).

To be sure, the feature is far from completely polished for the control freaks among us: You still must control the Histogram sliders with the Cursor if you wish to pinch the Heel or Shoulder. Press the Ctl (PC) button if you wish to activate the Clipping Warning unless you have selected Show Clipping for Black and White Points in the Dialogue Box Drop-Down Menu Options.

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