Bit Depth and Colour space
Bit depth is the tonal range which the image is recorded in. If you had your camera set to fine or basic then it will take the image in 8-bit jpg and if it was set to RAW then it will take a 16-bit RAW file. 8 bit has 256 values which is farl less than the 16 bit image which would have 32000 values giving much more room for editing.
8 bit and 16 bit images usually look identical at first with only a few minute differences in tones but if you were to perform a drastic levels edit and put it back to normal then the 8 bit image would gain banding and would posturize.
for example here we have a comparison of an 8bit grdient and a 16 bit gradient. They look identical with no differences but the 8 bit will become damged after a simple levels edit.
This is the two images after the levels edit. Again they look identical and perfectly gray. It’s when you try to put the levels back to normal, you get the problems.
You can see that the 8 bit no longer has the smooth gradiation that the 16 bit image has retained. This is called banding. So if you want to avoid this banding then you edit in 16 bit.
Colour space:
colour space is another option you need to think about when editing.
There are 3 main types of colour spacing. sRGB is the lowest form of gamma. If you edit in this you are getting rid of a ton of data that your camera has recorded. Adobe RGB has a much larger colour range and is the indutries more commonly used colour space for editing. Finally you have ProPhoto which has the maximum amount of potential for editing, combined with 16-bit this gives you much more room for error than an image in sRGB and 8 bit.
To change an image to 16 bit you need to open it in camera RAW first and change the setting like so.
you start by opening your image in Camera RAW making sure it is a RAW file. You then need to go into the setting to change the colour depth and bit rate by clicking on the highlighted area.
This is the box that will come up, you go to the highlighted boxes and change the top one to adobe RGB if it’s not already or ProPhoto. You then change the second one to 16-bit.
