Awhile back, I started to occasionally render out images in Maya with a z-depth version intended for adding a depth of field effect in post-production with Photoshop. There are a couple of different options in Photoshop, which utilize the black/white/gray information in the alpha channel to calculate how far away from the ‘camera plane’ the depth of field is most in focus. One, is the filter native to Photoshop, under Filters>Blur>Lens Blur, and the other is a proprietary add-on I’ve discovered made by Frischluft called Lenscare. They each have their strengths and weaknesses, but for the purpose of this entry, I’ll stick with the native Photoshop version.
I started wondering to myself, what it would look like to apply the filter to achieve a sort of similar effect to hand drawn art, or photographs, as an additional method to draw the attention of the eye to where you want it to be.
Here’s a drawing I did last year, and it’s oriented in a turned position, so it seemed appropriate to use this one for a test of this idea. So I proceeded to select the white space around the horse with the magic wand tool, refine the edges of the selection, inverted the selection so it highlighted the positive rather than the negative space, and moved over to the channels palette where I created a new alpha channel.
So, knowing that the lens blur filter utilizes gradations of black and white to delineate depth, with white being near and black being far, then for an abbreviated and quick design, let’s create a black/white gradient from left to right, so that the horse’s head and forelegs are brought ‘nearer’ to the viewer.
Now, going back to the RGB Layers palette, load the newly created alpha channel as your selection, and use the Lens Blur filter. The following window pops up, allowing you to adjust the location of the focal distance and the amount of blur.
And that’s pretty much it. With a little more effort on applying the lights and darks in the alpha channel, an even better approximation could be reached. Or, a diorama look could be applied by using only solid shapes of varying shades of gray to different objects in the work.