Perceptually, even 8 bit colour contains more than enough information for our eyes, although jpg compression, if it's set too high can lead to data loss, that's visible. Is it reasonable to assume that because I can see no banding (and the histogram is smooth black) then I have no problem and can have full confidence in that image ? That was probably poor practice anyway and easily corrected.Īre there any other steps that can create this issue? For instance could lowering say the red saturation and increasing the overall contrast create banding in the red?Īm I right in thinking that a histogram showing separate vertical lines rather than a solid blackĪrea is a graphical depiction of the problem ? Currently I just drag the histogram to roughly the right place in Darktable(16bit) and leave the fine tuning to the curves in Gimp which I prefer. It does not surprise me that I have not been aware of any problems in the thousands of images I have edited as the process required is excessive and foreign to my workflow.īut I will modify my workflow with the issue in mind. To replicate the problem it takes some fairly aggressive and conflicting steps with the curves tool or contrast slider (-50 then +50) The main issue with 8 bit is that it creates some limitations to the manipulation of the curves tool.Īnd after exceeding these parameters the image has visible banding.Īfter reading the article I can now easily replicate the problem. The first thing it clarified to me was that the difference between 8 and 16bit colour is invisible to us. Where better to get some info on 8bit editing than Photoshop and this excellent article Ĩ Bit Color vs 16 Bit Color - Working With 16 bit Images In Photoshop This thread is intended as a learning process for myself and others to understand the issues. Given that I have been operating with a dangerous amount of knowledge (sod all) I thought it was about time to do a bit of research on the issues with 8bit editing vs 16bit.īecause it would be hijacking the other thread I thought it wise to start this thread specifically about gimp and 8bit editing. I have gotten myself into a little bit of strife on a nearby thread promoting Gimp as a viable editor.

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