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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

Moire / Interlacing Issues in 4k R3D files

OK, I've got the file and I've merged the two threads to contain everything. I'll take a look after I grab something to eat.

Can you tell us how the R3D files are being viewed and processed on your end, Jon?
 
Jon Keeyes said:
We are trying to deliver a movie right now that was shot on a Red One MX and we have been encountering interlacing / moire issues on multiple shots from various days of production that are not able to pass QC. We have backtracked through everything and have now discovered that the moire exists within the 4k footage out of the camera.
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When I've encountered moire issues with feature projects, it usually happened because of a specific combination of vertical detail, lenses, and contrast, during a 1080 HD delivery.

My solution has typically been to just do a very tiny bit of vertical image softening (negative enhancement), and only on the precise areas of the shots affected. Generally, it's not tons and tons of shots; to name one example, it happened to me years ago on the baseball bleachers in League of Their Own. So this problem goes back many years and is not a Red-specific problem.

The other thing you could do is to take the problematic images to a specialty house like Lowry Digital in LA (818-557-7333) and have them fix it. That won't be cheap, but it will be done right.
 
I just downloaded the file and went through it a couple times. I'm not seeing anything weird here. Not on the fabric, the wall, her hair, the sheet, or the bg. Where is the moire (or artifact) you're experiencing?
 
Hi Guys,
Sincerely sorry about this. I just discovered that they did not upload a correct example. I'm new to the Red and Red Cine... apologies here. I now have Red Cine installed on my system so that I can view as well. Some of you asked for R3D Snapshots from the problematic errors. Here is a link to download a 12mb zip folder with the Snapshot files. Thanks again.
https://www.dropbox.com/s/1oqktitz40t5cu9/Red_Snapshot.zip
 
Just inspected the snapshots and looked around the high frequency detailed areas. I'm not seeing any moire, nothing that's jumping out at least. I do see subtle chromatic aberrations around some edges. A bit of image noise, but nothing truly out of the norm.
 
I'm personally not seeing any moire or aliasing. Where exactly are you seeing it?

Other than the bit of chromatic aberration from the lenses (which appears as green outlines around high contrast areas), I don't see any issues other than noise from the underexposure. Curious how this could fail QC? Looks good. Message me and I'll send you a link to the full res stills.


Your set looks awesome btw!
 
Matt. I'm not sure Jon would want you to post stills from an unreleased film on a public forum which can be webcrawled! The original clip was password protected?
 
ericyoung said:
Matt. I'm not sure Jon would want you to post stills from an unreleased film on a public forum which can be webcrawled! The original clip was password protected?
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I can take it down if it's an issue. These files are not password protected so anyone who wants to can download them...
 
Ditto on what the others are seeing. Both in the 2GB clip and the snapshots. No moire anywhere. I can see some things that could cause a moire to appear when down sampled -- the wood grain on the cabinet, the stripes on the mattress, for example. There has to be something going on with your viewing or processing that is causing the moire. I'm sure we can get this sorted. Looks like there's a bunch of us on the case. So far, I'm only viewing in Redcine-X. We need to know what is going on at your end so we can figure out where the problem is coming from. Could be happening in Premiere depending on project settings or other issues. Could have something to do with the scaling algorithm / filter being used if you're not working in or finishing in 4K...

This looks like a fun and interesting shoot, whatever it is. :)

BTW, it looks great at 1:1 pixels on a UHD display, the snapshots and the motion clip!
 
For whatever its worth, took a peek as well, and all looks pretty good. Agree with Matt, shots may be a little underexposed (possibly 2 stops), but nothing outrageous. Some CA isn't surprising either. Agree with Bob too that a motion clip may be provide more clues..
 
Been There

Been There

I had this very issue on a recent project and when we backtracked we found that at the colour grade coming from Resolve had the wrong output setting and was outputting at 1/4 Debayer. It looked surprisingly good at first inspection but on certain shots with fine detail you could see moire and stair stepping. Easy fix with a second output from Resolve with the "force to highest quality debayer" checkbox ticked.
 
Tom Gleeson said:
I had this very issue on a recent project and when we backtracked we found that at the colour grade coming from Resolve had the wrong output setting and was outputting at 1/4 Debayer. It looked surprisingly good at first inspection but on certain shots with fine detail you could see moire and stair stepping. Easy fix with a second output from Resolve with the "force to highest quality debayer" checkbox ticked.
Click to expand...
Very important note. This is a killer issue in Resolve, and users should stay right on top of this one.
 
I talked to the lab and they did indeed put up an incorrect shot. They are going to get me another shot that will only be two to three seconds long but prominently displaying the moire. I hope to have it up within a few hours for you guys to review. I appreciate the help in trying to figure out what is going on here.
 
Jon Keeyes said:
I talked to the lab and they did indeed put up an incorrect shot. They are going to get me another shot that will only be two to three seconds long but prominently displaying the moire. I hope to have it up within a few hours for you guys to review. I appreciate the help in trying to figure out what is going on here.
Click to expand...

Jon, can you clarify? Is it you seeing this problem or your lab? Does the issue appear using redcine-x? Or did you notice this after the final grade from your grading software?
 
Hi Bob. Just to clarify for everyone, I'm the director of the movie and not an editor by trade. My editor is out of pocket for a week so I'm having to take the lead on this as we're dealing with QC and distribution deadlines. We have seen some slight moire throughout editing but really didn't think anything of it. Once the final movie was sent for QC, that's when it became an issue because of the "rejected." In backtracking through the problem, we started wondering if it had to do with the color grade, but discovered the moire was in the base ProRes files converted from the 4k footage. We then started thinking it had something to do with the conversion of the 4k footage but the moire kept appearing in the ProRes files (my editor's broadcast monitor is broken so he's only being able to see footage on his hd computer monitor). Finally, the lab requested the 4k footage to review and they determined that the moire is in the 4k footage. I have not personally seen it yet in the 4k footage. I just got RedCine loaded onto my computer last night so I can start seeing what the lab is seeing as they provide examples.
 
Very curious about the outcome.

I bet it's not in the R3D! ;-)

Pat

PS: Looking at the snapshots I was thinking : People need to use light sometimes.
 
I just received more information. I will have a clip available in a couple of hours. How best to provide it to all of you for review? It's 600mb. I don't mind putting it on a Dropbox folder link to download (I can then remove it tomorrow).
In talking with them, I did get some more information. First, the lab is not viewing it in 4k as they don't have the capabilities to do so. They are viewing a scaled down version at 1920x1080. So the question comes back around to... is it in the scaling? Does it have something to do with the DeBayer. I should have the new sample shortly.
Thanks.
 
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