Apple Shake 4 - Manual (Page 412)

412 Chapter 15 Image Processing Basics
You might need to use a higher bit depth when employing certain nodes, such as
Emboss and Blur, since they naturally create smooth gradations. In the following
example, the image on the left has a Blur node and an Emboss node applied. At 8 bits,
terracing appears. By inserting an Other—Bytes node at the beginning of the node tree
set to 2 bytes (16 bits), the Emboss effect is smoothed.
Be sure to increase the bit depth of the image before the Blur node. This does not
mean you need to insert a Bytes node before every Blur. Rather, use the Bytes node
when you plan to apply numerous operations to a blurred image. Why? Because
blurred images are likely to display unwanted banding after multiple operations are
applied.
8 bits 16 bits
2-bit image, 4 values per channel
possible 16-bitimage, 65,535 values per
channel possible