Weird gradient in sky.

[Nocturnus]

I have one picture that came out with a very nice blue sky. When I use SilverFX to convert to B&W, I get a very nasty gradient in the sky. I can not see any type of gradient in the sky in the color image. Anyone had something like this happen before and is there a easy way to fix it?



I'll post the color image when I can find it. That's not jpeg compression in the image, you can see that in the original after I convert it.

[Jake]

I don't know anything about SilverFX, but make sure the image is 16bit and not 8bit.

[Nocturnus]

Tried it 16bit, same thing. Shows up if I do a grayscale conversion. I'm guessing it's there in in the original color image, jut not easy to see.

[Jake]

Was it shot RAW?
I would try to do the B&W while staying in whatever RGB mode you're working with vs going to grayscale.

[Nocturnus]

Yes, shot in raw. I did a raw -> SilverFX and it was there, and did a raw -> gray scale and it showed up also (did the gray scale just to see if it would show). I guess I can smooth it out in PS if I really need to.

[Jake]

Banding can be a pain to get rid of. Try going 16 bit RAW > B&W via channel mixer in PS and see if it pops up. Sometimes the banding can be worse in a certain color, so with channel mixer you can maybe pin point wheres it's happening.

[texkam]

Anyone had something like this happen before and is there a easy way to fix it?

Yes, and noise is your fiend. Do an internet search of "banding in gradients" for a variety of fixes to this problem.

[Nocturnus]

Cool. I'll give that a shot when I get home tonight.