dorky bit depth question

[kkamin]

I learned that a pure black and white image (just 2 shades: solid black 0,0,0 and solid white 255,255,255) is a one-bit image, because the pixel can either be black or white.

When you move to gray scale channels, you have 8-bits per pixel. Each pixel can be 256 shades of gray. Why does the number come out to 8 for the bit depth? Is that how many binary numbers it takes to produce an integer between 0-255?

 

[Bitter Jeweler]

Yes.

 

[dxqcanada]

2 to the power of 8 = 256 (0 - 255)

 

[kkamin]

2 to the power of 8 = 256 (0 - 255)

so smart! :thumbup: Thanks to both replies.

What about the Pro Photo color space, I guess it is 16-bits per channel. How many shades of gray are there per channel? I've never worked in that color space before.