Bit-Depth

This Won't Hurt a Bit
Many photographers new to the concepts of digital image processing, when they encounter the phrase bit depth their eyes glaze over. They know that it has something to do with image quality, and that more bits are somehow better, but that's about it. Let's look at this relatively simple but often misunderstood topic and see if we can make sense of it.
We should get some basics out of the way first. A bit is the smallest unit of data. It can be 1 or 0, black or white, on or off. 8 bits comprise a byte. A byte (or 8 bits) can therefore represent 256 different states; 2 ^8th power.
Most of the digital world operates on 8 bit images. This includes your inkjet printer and usually your monitor. What this means is that 8 bits of information are used to create the image that you usually see.
A Short Digression
This is why you don't want (for example) to print a B&W image on an inkjet printer using just black ink. The printer would only be able to lay down 256 shades o...