Now, for the same image (small crop applied) after applying a Lightness Curve adjustment in Lab Mode (Well, it got bettah):
To use Lab, follow these steps to get started, but as with all recommended post-processing techniques, experiment to find out what works best for you.
1. Open file, duplicate the Background by choosing >Ctl+J, and then choose >Image >Mode >Lab Color. Photoshop will ask to either flatten the image or apply the effect to the current layer only. Choose the current layer so as to preserve the integrity of the original background or other layers.
2. Create a Curves adjustment layer.
3. Choose one of three channels, Lightness, A or B. Lightness allows for fine control of contrast, while channels A and B can be used to correct color casts or warm/cool an image. Unlike a normal S-curve, extreme adjustments may yield the best result; a lot of trial and error is needed here.
4. Depending on the result, further adjustment of the combined effect of the three channels can be adjusted by controlling the blend mode (Soft Light usually works best as a start) and layer Opacity.
5. If working on a batch of images with similar scenes, lighting, etc, consider saving your adjustment as a Preset or Action.
6. There may be occasions where Curves adjustments in Lab mode are unnecessary. For simpler processing after Step 1, return to >Image and choose >Apply Image and a dialog box will open. Choose the layer that the effect will be applied to (e.g., Background Copy in this case).
7. Select the Lab Channel.
8. Select Soft Light from the Blending Mode drop-down menu and adjust the Opacity for fine tuning the result. Clicking the Preview box will toggle the effect on an off to compare it with the original.