Banding / Posterization in blues?

dillont

dillont

Well-known member
Hi folks,

I've been reading a lot on the "noise" and "banding" issues (in quotes), and have seen banding in some footage that I shot. It's actually pretty horrible in the blues (not so much in other primary colors). I'm confused as to what might be causing this, and how I can get around it? I've been playing with lights and a fog machine to push and pull the camera in lighting exercises, sensitivity, and how hard I can color correct before the image starts to break down.

I'm in love with this camera, and would love to know how to work around bandin/posterization issues.

Here's a link to the video (2 minutes, multiple scenes / setups / lighting scenerios) which shows the clear banding/posterization in the blues.



The video is still processing on vimeo so I'll provide a link to youtube video too:
http://www.youtube.com/watch?v=gq74vSSmWRs

Dillon
 
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Hi Jan,

Honored to have your reply to this! Here are the settings I used:

Lens: Lumix 14-140 Generally f4-9

ISO 400

Scene file settings:
Film cam (some VFR)
Detail -5
V Detail -5
Detail coring +2
Chroma Levfel -3
Chomra Phase 0
Color Temp Ach / Bch 0
Master Ped -2
Iris Level 0
DRS OFF
Gamma - Cine Like V
Matrix Norm2
Skin Tone DTL Off

"candle shot" was filmed with a Canon EF 50mm prime full open.
 
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Really? 100 views and no answer?

I turned down my chroma levels as suggested - are my eyes deceiving me and am I misinterpreting what I'm seeing? In the blues, I'm seeing crippling banding in the brightest areas of the image (and this is on all multiple computer monitors and a 1080p plasma monitor. I'm ignoring the 'banding' i see in the shadows and darkest areas of the image.

Any help here? Please?
 
Hmm, thanks. I'll give that a try. I tried coring at that number (I think it was Barry Green's coring) to minimize the noise - is this the balance between "noise" and "banding" that I've been reading about?

I'll try it out again tomorrow. Thanks again.
 
I have been testing with those same settings except Gamma HDNorm and Skn Dtl 1 (variations of Barry's). Is there evidence of it out of camera? I had issues with banding that I saw on Vimeo but not here that I attributed to their compression. It was not as apparent as what you have. The blue smoke looks pretty egregious. I'm sure you tube exacerbates but is it the cause... interesting there is little evidence of it in the magenta smoke.
 
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dillont said:
Hmm, thanks. I'll give that a try. I tried coring at that number (I think it was Barry Green's coring) to minimize the noise - is this the balance between "noise" and "banding" that I've been reading about?

I'll try it out again tomorrow. Thanks again.
Click to expand...

Too high coring remove details, 8bit (0-255) is also not very good for smooth gradient (fog) and chroma subsampling 420 (AVCHD) is right bad for color gradient. Coring 0 (-2) can help, I hope, but 422 will be better, 10bit will be the best.
 
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Here's some footage with natural fog (steam actually) what do you guys think of this? I don't see any noticeable banding or posterization. Then again, I'm not the best pixel peeper as my eyesight isn't all that great anymore and the lighting conditions are completely different than those Dillon tested in. However, there is fog and also blues.

 
Keep in mind that coring is used to minimize noise that is created specifically by adding detail. If you have taken away detail, it make no sense to have coring in there.
 
tflak I think that looks terrific. I don't see it. Some backgrounds seem to conspire to that effect more than others. Now how did you get that Chickadee, after the titmouse to hit it's mark like that? I checked again. That was not a cut. Excellent casting!
 
hscully said:
tflak I think that looks terrific. I don't see it. Some backgrounds seem to conspire to that effect more than others. Now how did you get that Chickadee, after the titmouse to hit it's mark like that? I checked again. That was not a cut. Excellent casting!
Click to expand...

Well, you're right - that was not a cut, however it was the third take. Damn chickadee played me for 10 extra ounces of sunflower seeds before hitting its mark.
 
Jan_Crittenden said:
Keep in mind that coring is used to minimize noise that is created specifically by adding detail. If you have taken away detail, it make no sense to have coring in there.
Click to expand...

Thanks for the tip, Jan. This was the first thing I shot with the AF100. And at this point, I was interested in avoiding noise (which was the current bugaboo of the moment) and so had pretty much followed Barry's suggestion:

The keys to getting the lowest noise are:
1) Use a detail level as low as you can stand; many folks are happy with -5 to -7
2) Using Norm2 as your matrix will dramatically lower the amount of perceived noise
3) Use a coring level as high as you can stand, although I find that +2 is more than adequate when paired with the other recommendations
4) Using either cine-V or b.press gamma will lower the appearance of noise
5) Use a slightly lower master pedestal, usually -2 to -3, to get proper deep black levels
 
I am trying to add a tiny bit of noise back in to help smooth out the banding. I've been comparing footage on my 7D on gradients and I can see that it looks almost dithered in the gradients. I think this is a good thing. I've not nailed down the best settings, but I think what i am going to do is get some gels and work with blue, green and red gradients just to see how they work compared to each other and the settings.
 
Rick, after my experience yesterday, I am considering doing the same thing. After reading all the posts and great suggestions in the other threads addressing certain concerns, I'm convinced that this camera is a powerhouse of total control - just need to know what does what to the image to get the image you want to dial in.

It's forcing me to become a BETTER artist! YAY!

Dillon

Rick Burnett said:
I am trying to add a tiny bit of noise back in to help smooth out the banding. I've been comparing footage on my 7D on gradients and I can see that it looks almost dithered in the gradients. I think this is a good thing. I've not nailed down the best settings, but I think what i am going to do is get some gels and work with blue, green and red gradients just to see how they work compared to each other and the settings.
Click to expand...
 
Jan_Crittenden said:
Keep in mind that coring is used to minimize noise that is created specifically by adding detail. If you have taken away detail, it make no sense to have coring in there.
Click to expand...

....yes Jan. I not understand why all users in their setting makes details controls at -5 /-7 and set the Coring at +2. It's clearly write on the Barry's book : coring level work on the edge of noise ( like a sort of defocus...) if you step down the details you don't have edge to minimize.

silvio bonomi
 
Well this kinda sucks,

I tried with different gamma settings and with different detail settings (with coring up and down) and the banding is there regardless. Though there is remarkable improvement under Cine-Like D. Uploaded vimeo file for comparison.

Settings are all the same except I cranked up detail levels and dialed down coring. Detail settings +6, detail coring -5.



Here's the youtube video link while the vimeo encodes:
http://www.youtube.com/watch?v=PtyYu2EtWNE

Thanks for all the helpful suggestons!

Dillon
 
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Hi,

I am not seeing the banding, and I think you should go look at it on a different monitor, played from a different source player like from the camera to a monitor. Additionally the settings you are using for plus detail and negative coring make even less sense than your earlier ones. Please reread what I wrote earlier about the relationship to detail that coring plays. I suggest that you reset your camera to the initial settings and start over. Record the same stuff again with the initial settings. If you are still getting the banding you have an issue with your monitor.

Best,

Jan
 
Thanks, Jan.

I'll give it another shot (pun intended). I do see much less banding in the lastest video I posted up (using cine like D). Admittedly, I did NOT look at the latest upload on the plasma HD monitor.

Will try again.
 
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