I've noticed using multiple GND's sometimes results in banding issues on the raw file in CS4. I normally use the noise reduction filter to clean up extra noise in the sky, but if there is banding it only serves to exacerbate the problem. Is it a lost cause or is there an effective way to reduce banding in RAW files and/or working PSD/Tiff files?
Posted by John Mumaw on February 12, 2010 at 8:13 AM
The only way I've ever seen to eliminate/reduce banding (outside of replacing the entire sky) is to add noise/grain to the area. May seem counterintuitive, but it really works. No amount of noise reduction or blurring will work because that only further damages image pixels.
If you don't have software to provide realistic looking grain, try downloading this scanned film grain with easy to follow instructions.
Posted by Wayne Rhodus on February 12, 2010 at 11:11 AM
Michael, have you considered leaving the GND filters in the bag and try bracketing exposures, then blend using software? That would eliminate the problem altogether and simplify in field shooting. Just a thought.
I would suggest trying to get to the root of the problem - you shouldn't be getting banding problems. Are you increasing the exposure in the sky in the raw conversion? If so, perhaps you should be exposing more to the right, or using a less strong GND filter.
Surface blur does a better job at removing artifacts than noise reduction or gaussian blur, and it preserves hard edges, but it obliterates fine detail... so if you have what should be a completely smooth sky it works wonders, but use it carefully (and with masks).
Posted by Matt Anderson on February 12, 2010 at 2:55 PM
+1 to what Floris is saying.
Your putting a band aid on the problem.
The noise reduction software in PS is useless. Get Noise Ninja. 65 bucks US, you can't lose.
Posted by James Hersey on February 12, 2010 at 9:37 PM
What color space are you using?
My experience with banding comes from compressing a large color space into a smaller one and how you do it (rendering intent). I would try using a different rendering intention and or check gamut warning.
Posted by David Bostedo on February 13, 2010 at 1:46 AM
And along the same lines as what James asked, are you processing your RAW files into 16-bit images?
I am converting to 16 bit using Pro Photo as my color space. Do you think that it could be a simple as being my monitor? I know if I look at the picture at different angles that I can see artifacts and things like that...
Posted by David Bostedo on February 15, 2010 at 12:30 PM
Michael - Looking at LCDs at odd angles can often produce some weird views. I wouldn't worry about it too much. It IS possible that the banding - posterization - could show up on some monitors but not others. It depends on how smoothly your monitor can render color. Can you post the image and get some feedback on here on whether or not others see it?
One thing to try is to re-develop your RAW file into a smaller color space...like Adobe RGB. It's possible that the wide space of ProPhoto could be partly to blame - which I've heard of, but never seem myself.
Finally, are you planning to print this image? Because that would be the true test of whether or not the posterization matters.
Posted by James Hersey on February 15, 2010 at 3:02 PM
David - It is showing up on several images. It is pretty much limited to blue skies. However, it easy to disguise/mask for web viewing and is barely noticeable, except to those very discerning. My concern is whether it will show up in print. I'll try to post an image tomorrow.
James - thanks for letting me know about this article. I'll check it out...
Sorry guys I haven't posted a test shot. I have been super busy and I don't sleep and do my editing at the same place - so it is not always convenient. Tomorrow I am going away for a couple weeks so I won't be able to post for a while. I do really appreciate everyone's time and when I post hopefully you guys can check it out for me. Thanks so much.
Posted by Chip Phillips on March 8, 2010 at 11:33 PM
Michael-does the banding show up in your prints? It could very well be a monitor thing.
I was noticing similar things, and didn't see it in prints.
Discussion
14 repliesIf you don't have software to provide realistic looking grain, try downloading this scanned film grain with easy to follow instructions.
Surface blur does a better job at removing artifacts than noise reduction or gaussian blur, and it preserves hard edges, but it obliterates fine detail... so if you have what should be a completely smooth sky it works wonders, but use it carefully (and with masks).
Your putting a band aid on the problem.
My experience with banding comes from compressing a large color space into a smaller one and how you do it (rendering intent). I would try using a different rendering intention and or check gamut warning.
One thing to try is to re-develop your RAW file into a smaller color space...like Adobe RGB. It's possible that the wide space of ProPhoto could be partly to blame - which I've heard of, but never seem myself.
Finally, are you planning to print this image? Because that would be the true test of whether or not the posterization matters.
http://www.creativepro.com/article/out-of-gamut-realizing-good-intentions-with-rendering-intents
How you shrink down a color to fit in your space can cause the banding / clipping
James - thanks for letting me know about this article. I'll check it out...
I was noticing similar things, and didn't see it in prints.