Difference between 8 bit and 16 bit in Photoshop


I have been working on Photoshop for quite some time now, but there is one thing that has got me confused till now. Is it better to be working on a 16 bit color mode or an 8 bit one? I know that the 16 bit should be better for images etc, as there are more colors to display, but on a file with lots of smart objects , what would be the best mode to work on? Also, does switching from 8 bit to 16 bit change the file size considerably?

I'm not sure whether this is a stupid question! So please be gentle, in case it is!

12/11/2014 8:05:00 AM

Accepted Answer

It depends on what you do. There are some advantages to 16 bits per channel images, as well as some disadvantages.

Some of the advantages are:

  • If you need to do a lot of color correction/other color based image manipulation you lose less data in transit.
  • If your data source has more than 8 bits of color then you can gain benefit from that.

Some of the disadvantages are:

  • Not all filters work in 16-bit mode
  • You use twice the amount of memory with all problems associated with this.

Basically as a rule of thumb if you do not have any specific reason to use 16 bit color, then you do not need to use it. There's no real advantage for the final image to be 16-bit unless you expect your client to do extensive color manipulation.

12/11/2014 1:46:00 PM

A friend of mine who is a photographer told me once that he converts his images to 16-bit while editing to reduce a loss of quality. I always wondered if this really had a visible effect, so i tried the following:

I started out with a 8-bit gradient.

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In the first image I adjusted the Levels in 8-bit mode. The second image was converted to 16-bit, edited and then converted back to 8-bit.

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You can see a slight difference with the gradients, but I really don’t know if it would be worth the effort (and the disadvantages joojaa already mentioned) in a real world scenario.