Photoshop - Visible color banding after saving.

[Roberto]

Hi,

Has anyone else perhaps had this problem. After editing an image which has a silky smooth background (no color banding visible in the edited version) and after saving (save as or save for web) color banding is almost always visible on the saved copy.

How can I solve this problem? Is it perhaps a Photoshop setting?

Thanks in advance.

[Forgiss - Sean Nel]

It often happens when you have a large colour gammut being squished into a smaller colour gamut. There are not enough colours to make smooth transitions, so the banding occurs... Then also, sometimes the colours are there, in the file, but your screen can't display them, so you see banding that is not actually part of the file...

[Roberto]

Hi Sean, thanks for the explanation.

Would it perhaps help if I photographed in raw and edited in 16 bit?

[Andre v]

Banding is also know as posterization. Link below explains it and offers some solutions to prevent it.

http://ronbigelow.com/articles/poste...terization.htm

[Roberto]

Thanks Andre.

[Henk Coetzee]

Would it perhaps help if I photographed in raw and edited in 16 bit?

Yes

[Forgiss - Sean Nel]

Hi Sean, thanks for the explanation.

Would it perhaps help if I photographed in raw and edited in 16 bit?

Yes, but if you still see the banding, chances are pretty good that it's your screen, and not the image. Although I prefer 16bit editing, it's not always required

[Roberto]

Yes, but if you still see the banding, chances are pretty good that it's your screen,

Sean, It's a Mac

Can I possibly mail you the image for you to take a look?

[SteveG]

banding/posterization can also be caused by JPEG compression

If you shoot RAW, and maintain 16-bit throughout your workflow and you STILL see the banding then I'd say it's the monitor profile. The banding may not actually be present in your image, but can appear when the image is converted to your monitor profile for display. Can't say for sure without having it in front of me. Feel free to mail me the image too, if you like. see signature for details.

[Roberto]

The problem is I enjoy photographing Jpeg, less space, less hassel and my genre (sport and wildlife photography) does not really require that I photograph RAW files in my opinion.

I believe you can not edit 16 bit unless you have a RAW file? Would it work then if you open a Jpeg file, save it as a TIFF then edit 16 bit?

[Stephen Child]

After doing a SFW and the banding is visable - I have heard that applying some noise to the banded areas (with a masked layer) helps to make the bands appear less obvious. Not too much noise - otherwise... well thats obvious...

[SteveG]

The problem is I enjoy photographing Jpeg, less space, less hassel and my genre (sport and wildlife photography) does not really require that I photograph RAW files in my opinion.

I believe you can not edit 16 bit unless you have a RAW file? Would it work then if you open a Jpeg file, save it as a TIFF then edit 16 bit?

first question: basically true. Although it's actually a 12- or 14-bit image in a 16-bit holder, depending on your camera.

second question: this might help you a little, for some edits, but not much. you'd get the advantage of being able to open and re-save multiple times without re-jpegging the image (is that a word?)

[AstraPics]

Roberto, without seeing your picture it's a bit difficult to offer an opinion, but I think SteveG has the correct answer - you are probably seeing Jpeg compression. This is almost always most visible in areas like the sky which have gradual, subtle changes in colour or density. Jpeg tries to save space by rendering those areas in only a few shades instead of thousands, resulting in the banding. To avoid that you should always move the Jpeg compression slider all the way to the right when saving the file. If you are choosing to save at a lower factor, say 10 or 8, then banding in areas without detail is almost unavoidable.