As mentioned previously, in boudoir retouching, it is a good idea to simulate blue pre-dawn (or post-sunset) light or warm post-dawn (or pre-sunset) light on the model. This gives the image interest, and the light helps to set the mood. One interesting variation would be to simulate cool, blue light streaming through a window on one side of the room, but have warm light coming through a second window on the opposite side of the room.
To accomplish this easy effect, two of Photoshop's Photo Filters can be used. Here is the beginning image of model Andrelica with no filters applied:
The base image of Andrelica.
I would like the have blue light on the left side of the image, and warm light on the right side. Start by adding a Photo Filter (available in the Adjustments Panel). Choose Cooling (80) filter from the drop-down menu, and set the Density: slider to 100%. I left the layer opacity at 100%. This covers the entire scene, which is not what we want. Hit G to bring up the Gradient Tool. Set the foreground color to black, make sure the tool is set to Foreground to Transparent and that Linear Gradient is selected in the Options Bar. Depress the Shift key and draw a horizontal line from the right edge of the image to approximately where you want the blue light to stop. As you can see, I ended up with a somewhat hard transition, which was not what I was looking for:
The transition between the edge of the blue light and the original image is far too harsh.
The solution is to select the mask of the Cooling (80) layer, and run a Gaussian blur (set to 435 Pixels) on it. This gives a better transition:
Now there is a more gradual transition between the Cooling Filter (80) layer and the original image.
Next, we will add Warming (85) layer to warm up the right side of the image just a bit more. Set the Density: to 100%. Since the effect we want is exactly opposite of the Cooling (80) layer's mask, we will use it. Option (Alt)-drag a copy of the Cooling (80) layer mask up to the Warming (85) layer. Hit Yes to replace the white mask with this one. Since we desire the exact opposite effect, with the mask selected, hit Command-I (Control-I) to invert the mask. We do not need to blur it, since this was already done. The effect was too much, so the layer opacity of the Warming (85) layer was lowered to 20%:
The right side of the image has been warmed just a bit.
Finally, we will add a vignette, not only to concentrate the viewer's attention on Andrelica, but to embellish the warm and blue light on the edges of the image. Add a Curves adjustment layer, and set its blend mode to Multiply. With the layer mask selected, paint over the model with a large, soft (0% hard), black Brush. The result was a bit too dramatic, so the layer opacity of the layer was set to 60%:
The final image.