What do you think?
1. Is 8-bit (and therefore JPEG) enough for output quality? or it dangerously nears the perceivable limit?
2. Is this very slight banding visible when printing?
3. Could I be being able to see these bands because of a bad calibration of my screen?
A thought provoking post. Your demonstration image appears to have a very steep contrast curve in the areas where the banding is apparent, which accentuates the banding. Whether or not banding would be present with more normal contrast is debatable. Before attempting to answer your question, I performed a Google search and reviewed some literature on the topic.Norman Koren
uses a theoretical approach based on the Weber-Fechner law, which deals with just perceptible differences in vision, and concludes that an 8 bit work flow for the final image is acceptable, but just so.
A Previous Thread
on LL discussed 16 bit printing, and some photographers claimed to see a difference. However, 16 bit printer drivers at that time appeared to be available only on the Mac with more recent versions of the Mac operating system. For us Windows users, the question may be academic unless special drivers supporting 16 bit are available. Mike Chaney
discusses 16 bit printing with the newer ink jet printers offering an expanded gamut and concludes that 16 bit printing might offer a small advantage for those using 16 bit ProPhotoRGB.
Since I use 16 bit ProPhotoRGB for my more critical work with my Epson 2200 printer, it would make sense to have a 16 bit driver, but I have not noted banding in my output and do not think that 16 bit output is necessary with this printer. With the more recent Epsons with still wider gamuts, it could help, but I can't comment on this. From a leterature review, I conclude that the improvement would be small. I would be interested in hearing from users of wider gamut printers, since I may upgrade printers in the near future. Also, I would like to know if 16 bit output would be possible with Windows 7 with Photoshop.