Render in parts gives banding

I was rendering a motorcycle model I picked up somewhere* and I noticed a problem with rendering in parts - this is 242a. You can see I hope in the attached image there is a difference in colour between the lower corner parts and the ones above ie the disk brakes have a line through them where the parts join. Seems like a bug where adjacent parts are not evaluated correctly…anyone else seen similar things?

*edit to give proper credit I see the model is by ‘varuag’ from India

RESOLVED
Well I found the problem and the answer is it is a weird coincidence and unlucky combination of scene set up and viewpoint producing an illusion. The lighting, materials, background and renderer are not in themselves at fault in this case - the camera does not lie - it is just the circumstance. I changed things a little and the issue was avoided. Apologies for a false alarm. Sure had me fooled. Thanks to those who stopped to offer assistance

Well the topic title states you have banding, have you tried turning up the dither slider? If you check the release logs it’s supposed to help with banding problems.

hmmm well perhaps banding is the wrong term…:o
I think dither is an overall effect? sort of adds noise?
here I just have a difference between the rendering of adjacent parts for some reason :confused: …sort of like specular got added twice or something…well …I don’t know how to explain it.
thanks for suggestion though :slight_smile:

Weird, because it doesn’t affect the rims, the bolts that mount the discs or the paintjob. I assume both discs share the same Material? Can you tell what type of lamp is lighting the discs (if a Spot then check Clipping) and whether the discs/lamps are on the same layer and if so are they on the same layer as the rest of the bike. Are there any Negitive Lamps? Maybe post the .blend so we can look at it.

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I have had the same effect of banding in renders and posted a thread about it, no solution was found and this banding seems to go all he way back to the earliest versions of blender, I think that maybe something in the lastest version has somehow accented the banding and made it more visible (personally I think this is a serious problem when it comes down to it a lot of the powerful features unique to blender cant be used if you have to render it in another renderer) .

Basically it seems the banding mostly affects the scene when you use the world backround. changing the dither settings or any other settings is useless. Best thing to do is use a backround sphere or plane and attach a picture to that, if and when you can. If you are doing still work this is a reasonable work around.

some people trying to make sky boxes have had similar problems. I saw some threads recently where the sky box or pano could not be made seamless. I think its the same problem. I dont think anyone came up with a solution.