If you select an area in your image (a person’s face for example), and then add an adjustment layer (such as Curves), clicking the Auto button, will make the adjustment based on the selected area. Then, you can always disable or delete the mask to apply the effect over the entire image. This produces a different result (based on the area selected) than if the Curve adjustment layer was added to the image without a selection and the Auto button clicked.
Changing the blend mode of a Curves (or Levels) adjustment layer on the Layers panel from Normal to Luminosity will restrict the adjustment to only change the luminosity (grayscale) value of the image, thereby eliminating an color shift that might otherwise take place.
There are times when you will want to use Image > Adjustments > Curves to modify an image instead of using an adjustment layer. This is true, for example, when adjusting a mask. The following shortcuts are handy when navigating the Curves modal dialog box. Note: these shortcuts are not always the same when using the Adjustments Panel to modify a curves adjustment layer.
Command (Mac) / Control (Win) + M displays the Curve Dialog Box
Command Option (Mac) / Control Alt (Win) + M displays the Curves dialog with the last used settings
With the on-image adjustment button (also known as the targeted adjustment tool or scrubby slider) off:
Command (Mac) / Control (Win) -click the image to add a point to the active curve only.
Command (Mac) / Control (Win) +Shift to add a point to all of the channels.
Shift -click in the image area to add Color Sampler point.
Option (Mac)/ Alt (Win) + Shift -click on a color Sampler point to delete it.
Click -drag on image to display a small dot on the curve corresponding to the value clicked upon.
Control (Mac) + tab and Tab (Win) will toggle focus from one point on the curve to another (as will the + and – keys).
Shift click to select multiple points on the curve.
Command (Mac) / Control (Win) + Delete to delete a point.
Use the arrow keys to move the select point one increment. Add the Shift key to move in greater increments (10).
Option (Mac)/ Alt (Win) + drag the black/white point sliders to display shadow/highlight that will be clipped to pure black/white.
Option (Mac)/ Alt (Win) + click the grid to toggle size.
Option (Mac)/ Alt (Win) + P toggles Preview on and off.
In the Levels, Curves, and/or Black and White Adjustment panel, Option (Mac)/ Alt (Win)-click the Auto button to display the Auto Color Corrections Options.
With the on-image adjustment button (also known as the targeted adjustment tool or scrubby slider) off, and the eyedropper tool on:
Command (Mac) / Control (Win) -click the image to add a point to the active curve only.
Command (Mac) / Control (Win) +Shift to add a point to all of the curves (channels).
PSCS5 -With the Point Curve panel active in the Camera Raw dialog, Option (Mac)/ Alt (Win) -click to set a point on the curve. Use the up, down, left, right arrow keys to precisely reposition the point as necessary. Control (on both Mac and Win) + Tab moves from one point to the next along the curve.
As is common in the many dialog boxes and panels throughout Photoshop, the Tab key moves between numeric entry boxes. For example, tab moves between the Input or Output options in Curves Adjustment panel (although in this case, this is a MAc only shortcut…). Note: one of the text/numeric entree boxes must be active in order to move to another.
In addition, once the box is highlighted, the up/down arrow keys increase/decrease the value by one unit. Add the shift key to shift the value by 10 units.
When the Curves Adjustments panel is active, Option (Mac)/ Alt (Win) + drag black/white point sliders to show clipping. Note: don’t drag the points in the curve, drag the black and white triangles below the curve. If you have selected the black or white point eyedropper and mouse over the image area, holding the Option (Mac) / Alt (Win) key will also preview any clipped values.
When the Curves Adjustments panel is active, Option (Mac)/ Alt (Win) + 2-6 to toggle through the different channels (2 = composite, 3 = Red, 4 = Green, 5 = Blue or 3-6 for CMYK etc.)
When using the On-Screen Adjustment (Scrubby Slider) and Eyedropper tools in the Curves Adjustments panel, the sample size is linked to the Color Sampler Tool. To quickly change the sample size while using the Curves Adjustments panel, Control (Mac) or right mouse -click in the image area and select the preferred setting from the list. Note: this will change the options for the Color Sampler tool.
When the Curves Adjustments panel is active, shift-click in the image area to set a Color Sampler. Shift -drag to reposition the Color sampler. Option (Mac) / Alt (Win) + Shift -click on sampler to delete it.
In the Adjustments Panel, Option (Mac) / Alt (Win) -click in the grid area to toggle more/less grid lines. (10% vs quarter-tone increment)
To delete a point on a curve, select the point and do any of the following:
• Press Delete/Backspace
• Command (Mac) / Control (Win) + click on point (on the panel or from the image area)
• Click and drag the point off of the grid
With the On-image tool selected on the Curves Adjustments panel (that’s the one that looks like the hand with the up/down arrow – otherwise known as the “scrubby slider”, as oppose to any of the eyedropper tools), Shift + (plus) will select the next point on the curve and Shift + (minus) will select the previous point. Shift -click multiple points on the curve to select more than one and move them all at once. Command (Mac) / Control (Win) + D will deselect all selected points.
With the On-image tool selected on the Curves Adjustments panel (that’s the one that looks like the hand with the up/down arrow – otherwise known as the “scrubby slider”, as oppose to any of the eyedropper tools), hovering the cursor in the image area will display a preview circle (bouncing ball) over the corresponding value on the curve.
• Click in the image area to add a point to the curve.
• Click and drag up/down in the image area to add a point on the curve to lighten/darken the targeted value or
• Use the up / down or left/right arrows to move the selected point. (Add the shift key to move it in larger increments.)
