Hi not sure if anyone has shared this previously, but this is a pretty easy way to equalise contrast and is worth doing as one of the final steps in your retouching just to see what it does. It darkens the lighter areas and lightens the darker areas.
1. Duplicate your background layer (Ctrl+J) if you only have one layer or duplicate merged visible layers (Shift+Alt+Ctrl+E). Set blending mode to Overlay and opacity to around 75%
3. Desaturate the layer (Shift+Ctrl+U) and then invert it (Ctrl+I)
4. Select Filter>Blur>Gaussian blur and blur the layer. The amount the blur depends on your image and resolution so play around with the Preview box checked to see what produces the best result.
5. You can play arund with the opacity level or blending mode as well to see what looks best. Use a layer mask to mask out the effects in areas where it doesn't look as good/too strong.
Here's a before and after image to illustrate what this does
Before
After
1. Duplicate your background layer (Ctrl+J) if you only have one layer or duplicate merged visible layers (Shift+Alt+Ctrl+E). Set blending mode to Overlay and opacity to around 75%
3. Desaturate the layer (Shift+Ctrl+U) and then invert it (Ctrl+I)
4. Select Filter>Blur>Gaussian blur and blur the layer. The amount the blur depends on your image and resolution so play around with the Preview box checked to see what produces the best result.
5. You can play arund with the opacity level or blending mode as well to see what looks best. Use a layer mask to mask out the effects in areas where it doesn't look as good/too strong.
Here's a before and after image to illustrate what this does
Before
After