Dennis Klau

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Open the layers window.

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Click on the create new fill or adjustment layer icon

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I’ve selected Levels here but you can select one of the other adjustments to make an adjustment layer.

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Then you make the adjustments to the layers which are below this layer. If layers are above it, then adjustments made here will have no effect.

not that the first image is not changed, and you can go back and change the affect of the adjustment layer at any stage.

You can also create a mask if you only want it to adjust parts of the image

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