Earlier this year, I was animating a simple talking character to be used for roughly 60 seconds. For some reason, I decided that I wanted to forgo the hard edge shadow that I was so familiar with from my favorite cartoons (Justice League, Batman, Superman, etc) and go for a softer, more "Disney" style shadow. Basically, Disney has a smoother, more blended look to their shadows and, for the life of me, I couldn't figure out how to achieve that on my own. Well, I eventually saved up my money and got CS5 and found out about "Lens Blur." Not sure what Lens Blur is really supposed to do, but it filled my purposes beautifully.
So go ahead and check your version of Photoshop, if you have Lens Blur in there, feel free to follow along.
Step 1: Scan in your original art.
I usually like to use about 300 dpi (dots per inch) and set my scanner settings to Black and White. I useful tip I learned Producing Independent 2D Character Animation: Making & Selling A Short Film by Mark Simon is to draw all of your rough art in a "non-photo blue" pencil. Xerox machines and scanners (set to B&W) can't see the blue. That way, you can rough your art out first and then ink over it with your black pen. Another tip is to use a red pen when inking to mark your shadows. It will show up as black on the scan, but you can keep track of shadows with your original art near by.
Original Art:Scanner Set to B&W:
Step 2: Color in your Art Work
Go ahead and start coloring your art work. I usually use ToonBoom to color in my art work because of the ability to adjust my palette after I've used the "Fill Bucket." You can also fill your work in with Photoshop and just paint in the black lines. (Use the "Wand" tool and select the black lines. Then just go over it with the pencil).
Step 3: Selecting the Colors to Blend
First Select the "Wand Tool."
Next, hold in the Shift Key and select all colors that need to be blended (the normal value, shadow, and highlights). Make sure "Contiguous" and "Anit-Aliased" is NOT checked while you are selecting.
Step 4: Select Lens Blur
Go up into your Toolbar and select "Filters", then "Blur", then "Lens Blur".
Once inside the Lens Blur's editor, start adjusting the "Shape" and "Radius" until you get a nice, smooth transition between the colors (or whatever effect you are looking for).Hit OK and you should have it. Feel free to go back and use it with any other sections of the same picture. Just remember that they all have to be of the same color range. Let's say I also had shadow values on the cape, if I selected it too, then it's colors would bleed into the tights' selection.
Now, a couple of things to keep in mind when using this.
First: The reason to use Lens Blur as apposed to any others is because Lens Blur repeats the edge pixels. Use of Gausian Blur or any others results in Photoshop pulls color from outside the selection. (Click for larger view. Notice Yellow is bleeding into the blue, even though its out of the selection.)
Second: Place your shadows and highlights careful when drawing and compensate for the natural spreading of the colors that happens with the Blur. In the following picture, I did not plan accordingly and the highlight bled past his chest and over to his arm (where there shouldn't be a highlight). I'd love to say that I was really smart and planned that on purpose to teach you a lesson, but I'm not. (I adjusted the contrast so you could more easily make out where the highlight is bleeding over the line.)
In closing, if you are looking at my final product and thinking that you could do the same thing with "Bevel" and "Emboss" effects, then only blame my use of shadow. In further works, I'm going to be more mindful of using it to express shape and form and try to avoid any type of symmetry or parallel lines that may be causing that effect. Also, I'm pretty sure I could achieve this effect on a series of images using Actions and the Select Color Range feature, but have not tested it enough. Hope this helps some of you out.