PS banding on MONITOR but not in lightroom.

[Chaca]

Hey,

Cant find the solution anywhere! PLEASE help.

Never have had this problem before. I do astrophotography and use deep sky tracker to stack multiple images together to form one big .tif file.

When viewing it in ligthroom looks fine. When opening in photoshop I get weird onion banding rings that disappear when zoomed in. I have tried turning off GPU with no help. I have updated the graphics card drivers and photoshop too but nothing is working.

Like I said before this is all new. Is there a setting that im not noticing that is making the problem? Why does it show up in PS and not in LR? Also if I open the image in Camera Raw in PS it goes away.

Photos are of the banding zoomed out(1). Zoomed in(2). banding disappears after one more zoom in click (3)

[D Fosse]

Could you please make actual screenshots and post those, instead of photographing the screen? It's impossible to get a realistic impression here.

Are these files 8 bit or 16 bit? What file format - specifically, are they jpegs?

General remarks:

If you're working in 16 bit depth, any banding you see is in your display system. The display pipeline works in 8 bit depth, most laptop and gaming displays are even 6 bit plus dithering. In an 8 bit system, you have only 256 discrete steps per channel.

Jpeg compression often adds banding on its own, quite aside from being 8 bit. The color component is more aggressively compressed than the luminance component.

The big problem with banding is that it's cumulative. In an 8-bit chain, several components may introduce a little banding on their own, each nothing too obvious, but they layer on top of each other and pile up. The end result can sometimes be quite ugly. So then you can have a long chain: 8 bit data > jpeg compression > monitor profile > video card/driver > calibration tables (if any) > display panel.

What's absolutely certain, is that a 16 bit file does not inherently have any banding whatsoever. There's 32 768 individual steps per channel.

Oh - you normally see a lot less banding in Lightroom compared to Photoshop, because Lightroom uses dithering on the output data. Photoshop doesn't.

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All that said: If this really is as bad as it seems here, I would suspect either a buggy video driver, or a defective monitor profile from your monitor/laptop manufacturer.

[Chaca]

Sorry for the late reply.

They are .tif files

They are 32 bit which I turn down to 16bit in PS.

I am zoomed in 62.08% on this next image.

This image is 67.73% zoomed in. As you can see all banding is gone.

Some things I noticed. I merge the layers the problem lessens. In camera RAW in PS there is no problem. If I Shift+ctrl+Alt+E and creat a new image with all edits the problem goes away. As shown here:

My monitor is an 8 bit. Is there a setting I can change in PS or windows that would fix this problem? Its nearly impossible to edit photos with fake banding showing up on my monitor. I have edited photos like these before and never had a problem with ghost banding.

I also have done a color calibration with a spyder 5 and its has the same problem. And all GPU drivers are up to date as well. I have also turned off GPU in PS but that didn't help either.

Thanks sooooo much for your help!!!!

[D Fosse]

OK. This is odd.

The thing is, at less than 66.67% zoom, the cached preview is always 8 bit, even with a 16 bit file. So it could be that a cumulative effect is starting to show up there, as I explained above. Even so, this seems excessive and I can't explain it.

There is something called the image pyramid, which is a series of cached downsampled previews at fixed zoom percentages, presumably for rapid retrieval. You should see this as a setting called Cache Levels in Preferences (the default is 4 levels). Apparently something happens at the 66.67% point.

You could try to change the number of cache levels - but I think what I would do first is to reset PS preferences. A corrupt prefs file can sometimes cause erratic and unpredictable behavior. Save out your actions, brushes and so on first.

[Chaca]

Hello,

I have tried resetting PS preferences but that did not fix anything. I have also changed the Cache Level to max(8) but still looks the same.

Can it be the .tif file? I shoot about 75 raw photos with Sony a7rii and use a program called Deep Sky Stacker to stack all 75 photos into one tif image for astrophotogrphy.

Also why doesn't PS use dithering on the output data? Can I turn it on somehow?

[D Fosse]

Dithering only applies to 8 bit files and AFAIK only with the gradient tool. But this looks beyond dithering.

Since it disappears at 66.67% and above, I think you can rule out both Deep Sky Stacker and the camera. The only clue seems to be that it happens at the point when Photoshop drops to 8 bit data instead of 16 bit data. That could mean a cumulative effect tipping over the visibility threshold. At the moment that's the best explanation I have.

Are these ProPhoto files? Try Adobe RGB. ProPhoto is vulnerable to banding because it is so huge that the "useful" values in the middle get very compressed.

[D Fosse]

One more thing: I notice your histogram is full of gaps. It shouldn't be unless you have a very steep curve applied, in combination with a selection-based mask. Selections are always 8 bit even in a 16 bit file (legacy code I assume).

Try to refresh the histogram by clicking the triangle. If the gaps are still there, it's in the data.

[Chaca]

I think this is what you mean. 

I changed it to Adobe RGB with the convert to proflie as pictured above. It changed very little when adding the curves levels. And yes I do add a very steep curves level. This is my normal workflow with astro photos because of how faint the images are. This is also the same steps that many Youtubers use in their workflow but non seem to have this problem and this problem is new within the past 3 weeks or so.

Here is the histogram before and after I click on the triangle.

after.

and here is the same image saved as a JPG.

[Chaca]

Also why would doing Shift+ctrl+Alt+E fix the problem?

[D Fosse]

"Also why would doing Shift+ctrl+Alt+E fix the problem?"

Because that adds a flattened composite layer with all adjustments baked into the 16 bit data.

I'm getting more and more convinced that you are seeing a cumulative result of many independent factors, resulting in a banded preview. When you commit all adjustments and all calculations are carried out, in 16 bit depth!, it goes away. The 66.67% threshold is where the on-screen data drops to 8 bit depth, and that brings all the banding out.

As long as you see no banding at 100% view, your file is fine.

Yes, this highlights a number of Photoshop issues in on-screen preview generation. With today's hardware, it should be possible to do all preview calculations on the full data, in full bit depth. But there is probably a lot of legacy code there, deeply embedded, from a time when computers struggled with big image files.