Use Photoshop CS: Image, Adjust, Highlights/Shadows. It is simple and brilliant!!!
If you have a picture with - for example - a person against the light and that person is in shadow - or indeed, any picture with lots of shadows.
>1 Create a greyscale copy of the original image by - Opening the image, choose image | Duplicate and click OK. Now select lmage | Mode | Grayscale, which will convert the image to grayscale, (you MUST create the duplicate in this way)
>2 Using this grayscale copy, select Filter | Blur | Gaussian Blur and enter a radius between 3 and 6 pixels. Choose Select Select all (or CTRL A)
>3 Bring the original colour image window to the top by clicking on it then choose Select | Load Selection. Set the background channel to Black, check the Invert box and click OK. This should put the marching ants around the shadow areas.
>4 Now choose Edit Fill. Under Contents, select 50% Grey. Under opacity enter 100%.Under Mode, select Colour Dodge, then click OK. Choose Select Select none (or CTRL D)
>5 The resulting image should have the shadows lifted, or considerably improved.
>6 If the shadows are really dark, try it two or even three times.
>7 It's worth storing this one as a Photoshop Action for rapid deployment.
>1 Open an adjustment layer: in Photoshop 4 CTRL + click on the new layer icon; in Photoshop 6 click on the adjustment layer icon.
>2 Select 'Curves' as the Type and click 'OK'.
>3 Click on points on the curve at 77/77, 102/102 and 128/128 to anchor them.
>4 Click twice on the lower part of the curve to make two new points at 50/62 and 15/33-- or at any other position of your choice.
>5 Save the file in an appropriate folder. (NB I called my first such file "Shadows AL vi [date]" (where 'vi' means 'version 1').When I subsequently modified the curve, I saved it as "Shadows AL v2 [date]". Each such saving occupies a massive 1kb on my hard drive, and I can at any time substitute an earlier curve if I think it might be more suitable than the current one.)
>6 Click 'OK' to apply.
>7 Try an initial Opacity of, say, 60%.
>8 This scheme has, I suggest, a number of advantages over the 'Coming out of the shadows' procedure:-
>9 Toggling the adjustment layer on and off by clicking on the eye symbol gives a rapid 'Before' and 'After' comparison.
>10 Altering the adjustment layer opacity instantly varies the effect over the entire image
>11 Painting in the adjustment layer mask with black (or grey) prevents (or reduces) the adjustment layer from having its effect on that part of the image -- extremely useful sometimes, especially if used in conjunction with the opacity setting
>12 Modifying, saving, loading and using such an adjustment layer is very easily carried out.