Cross Hatching Wont Go Away

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David Hessel

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Re: Cross Hatching Wont Go Away

PostFri Sep 23, 2016 2:02 am

I have been doing compositing and computer graphics for over 15 years, in the files posted in the link a few posts up has this effect backed in, as I said the pattern can be used to general a mask the data can be isolated and turned into a black and white mask that be moved around and reapplied in other places. Whatever settings you have found are just a band aid hiding the issue. I have worked with scaling imagery of all sizes and resolutions even over 16k. It IS there. 15 years of experience using the same software for years working with all sizes and resolutions of files and never seeing this and now the footage off this camera displays it and it is suddenly a software scaling issue. Not likely.
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PaulDelVecchio

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Re: Cross Hatching Wont Go Away

PostFri Sep 23, 2016 2:17 am

David Hessel wrote:I have been doing compositing and computer graphics for over 15 years, in the files posted in the link a few posts up has this effect backed in, as I said the pattern can be used to general a mask the data can be isolated and turned into a black and white mask that be moved around and reapplied in other places. Whatever settings you have found are just a band aid hiding the issue. I have worked with scaling imagery of all sizes and resolutions even over 16k. It IS there. 15 years of experience using the same software for years working with all sizes and resolutions of files and never seeing this and now the footage off this camera displays it and it is suddenly a software scaling issue. Not likely.


Maybe that file you are working with has an issue then. The ones I have only show it when the scaling quality is lower. As far as my settings being a bandaid, well, ok... but...

Whatever I'm seeing can be fixed in Avid, Resolve, Premiere, After Effects, and Final Cut X. Maybe the issue is with some cameras. I'm not sure. I'm interested in why the issue I'm seeing is showing up on only 4.6k footage according to some people. Maybe what I'm seeing and what you're seeing are variations of the same thing and yours can't be fixed while what I'm seeing is an issue with settings, although why they are supposedly unique to this camera I don't know.
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David Hessel

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Re: Cross Hatching Wont Go Away

PostFri Sep 23, 2016 2:27 am

Phillip Bergman wrote:
PaulDelVecchio wrote:I just played around with some files Eli sent to me. I saw the cross hatch pattern in VLC player on everything above HD except UHD 3840x2160, which is a multiple of 1920x1080. Here's what I found.

In Premiere on Windows 10, I saw the cross hatch pattern. Right click on the viewer and switch it to HIGH QUALITY PLAYBACK and you'll see that it goes away.

In OSX Sierra, I don't see the crosshatch pattern at all. Not in VLC or Final Cut 10.

Eli didn't see the pattern in Quicktime 7 or on another Windows machine he tried.

All of this leads me to believe this:

The pattern is NOT in the source files. The pattern is a SCALING ISSUE that results from a lower quality scaling algorithm. When I switched to HIGH QUALITY PLAYBACK in Premiere, it went away. Being that UHD is double 1080, the lower quality scaling algorithm(s) may not have an issue with down scaling to HD or with any type of scaling. With frame sizes NOT multiples of 1920x1080, it shows up.

For everyone having an issue, what is your monitor's resolution? I tried it on my desktop workstation that has 2 monitors. 2560x1440 and 1920x1200. I also tried is on my Mac laptop Macbook Pro Retina.

I'm wondering how much of this has to do with software (OS, Video Player, etc) and the resolution of your monitor. That seems to be the issue here. I do not see this issue in Resolve.

Again, I am 99% sure that this is NOT A PROBLEM WITH YOUR SOURCE FILES but rather it's a result of a lower quality scaling algorithm that is being used in the software you are seeing this in.

If anyone wants to send me footage, I'd be happy to test.



Hey Paul,

I use 1920x1080 monitors and also my Macbook Pro Retina screen. I see the crosshatching on both when playing in VLC, Quicktime, REsolve, Premiere. Here's some clips you can download from google drive and check them out. Both shot at ISO 800 Prores 422 I believe (maybe LT). On the one outside you can see the crosshatching in the shadows, and the one inside you can see the crosshatching all over. I am very curious about what you said about not seeing it anymore in OSX Sierra. I will install that right now and test it out.

https://drive.google.com/drive/folders/ ... sp=sharing


Fair enough all I can say is that the files in this post have the grid effect baked in. I cannot speak for any other files from any other camera since these are the only ones I have looked at personally.
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Re: Cross Hatching Wont Go Away

PostFri Sep 23, 2016 2:27 am

Ok so further testing...

This first image shows the grid pattern. Bring it up full screen/open it in a new tab/download it. It's clear it has a grid pattern. That's when I use "Bilinear" or "Optimize for Playback" in Resolve, which is located under IMAGE SCALING > RESIZE FILTER.

Image


This one doesn't have the issue. That's because I used "Sharper" (you can use "Smoother" too and not get the issue) under IMAGE SCALING > RESIZE FILTER.

Image


So hopefully that helps people too.
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David Hessel

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Re: Cross Hatching Wont Go Away

PostFri Sep 23, 2016 2:51 am

PaulDelVecchio wrote:
David Hessel wrote:I have been doing compositing and computer graphics for over 15 years, in the files posted in the link a few posts up has this effect backed in, as I said the pattern can be used to general a mask the data can be isolated and turned into a black and white mask that be moved around and reapplied in other places. Whatever settings you have found are just a band aid hiding the issue. I have worked with scaling imagery of all sizes and resolutions even over 16k. It IS there. 15 years of experience using the same software for years working with all sizes and resolutions of files and never seeing this and now the footage off this camera displays it and it is suddenly a software scaling issue. Not likely.


Maybe that file you are working with has an issue then. The ones I have only show it when the scaling quality is lower. As far as my settings being a bandaid, well, ok... but...

Whatever I'm seeing can be fixed in Avid, Resolve, Premiere, After Effects, and Final Cut X. Maybe the issue is with some cameras. I'm not sure. I'm interested in why the issue I'm seeing is showing up on only 4.6k footage according to some people. Maybe what I'm seeing and what you're seeing are variations of the same thing and yours can't be fixed while what I'm seeing is an issue with settings, although why they are supposedly unique to this camera I don't know.


Question, are you rendering out these to UHD files after applying your fixed settings and viewing them 1:1 or are you just looking in the preview window in resolve?
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Re: Cross Hatching Wont Go Away

PostFri Sep 23, 2016 3:22 am

David Hessel wrote:
PaulDelVecchio wrote:
David Hessel wrote:I have been doing compositing and computer graphics for over 15 years, in the files posted in the link a few posts up has this effect backed in, as I said the pattern can be used to general a mask the data can be isolated and turned into a black and white mask that be moved around and reapplied in other places. Whatever settings you have found are just a band aid hiding the issue. I have worked with scaling imagery of all sizes and resolutions even over 16k. It IS there. 15 years of experience using the same software for years working with all sizes and resolutions of files and never seeing this and now the footage off this camera displays it and it is suddenly a software scaling issue. Not likely.


Maybe that file you are working with has an issue then. The ones I have only show it when the scaling quality is lower. As far as my settings being a bandaid, well, ok... but...

Whatever I'm seeing can be fixed in Avid, Resolve, Premiere, After Effects, and Final Cut X. Maybe the issue is with some cameras. I'm not sure. I'm interested in why the issue I'm seeing is showing up on only 4.6k footage according to some people. Maybe what I'm seeing and what you're seeing are variations of the same thing and yours can't be fixed while what I'm seeing is an issue with settings, although why they are supposedly unique to this camera I don't know.


Question, are you rendering out these to UHD files after applying your fixed settings and viewing them 1:1 or are you just looking in the preview window in resolve?


Rendering them out then looking at them in Resolve, Premiere, After Effects, and FCPX. I also tried uploading to Vimeo and Youtube and I don't see it in either. I do see it when I play it back in VLC.
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Re: Cross Hatching Wont Go Away

PostFri Sep 23, 2016 3:29 am

I'm also doing further testing. for me bottom line is any footage shot above 2k brought into resolve and rendered onto matching timeline of the same resolution will show this pattern.

If I shoot UHD 4k 4.6k and bring into resolve and render it with HD output file the pattern is gone.
So right now my 4.6k camera can not output in 4k.

Can we get BMD response here?
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Re: Cross Hatching Wont Go Away

PostFri Sep 23, 2016 3:50 am

So now, what concerns me is if we're seeing this in media players but not in editing software with certain features enabled, then are we going to see this in our final products? I haven't seen this with my camera, but for those with this issue, this is a definite concern.
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Re: Cross Hatching Wont Go Away

PostFri Sep 23, 2016 3:58 am

PaulDelVecchio wrote:Rendering them out then looking at them in Resolve, Premiere, After Effects, and FCPX. I also tried uploading to Vimeo and Youtube and I don't see it in either. I do see it when I play it back in VLC.


I applied the exact same settings you posted screenshots for resolve on the previous page and yes in Resolve the problem appears to be gone. By changing the scaling algorithms to higher quality ones and forcing a 1080 output regardless of the timeline resolution made the issue go away.

However when I rendered out the timeline un-scaled, at original UHD, the cross hatch pattern is still there on the output file.

This is just a small section from the bottom right enlarged to make it easier to see.

UM46K.jpg
UM46K.jpg (24.99 KiB) Viewed 19901 times
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Re: Cross Hatching Wont Go Away

PostFri Sep 23, 2016 4:03 am

David Hessel wrote:15 years of experience using the same software for years working with all sizes and resolutions of files and never seeing this and now the footage off this camera displays it and it is suddenly a software scaling issue. Not likely.


What other cameras have you worked with that originate without an OLPF ? The do call them AA filters too. I wonder if that's the issue ?

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Re: Cross Hatching Wont Go Away

PostFri Sep 23, 2016 4:30 am

David Hessel wrote:
PaulDelVecchio wrote:Rendering them out then looking at them in Resolve, Premiere, After Effects, and FCPX. I also tried uploading to Vimeo and Youtube and I don't see it in either. I do see it when I play it back in VLC.


I applied the exact same settings you posted screenshots for resolve on the previous page and yes in Resolve the problem appears to be gone. By changing the scaling algorithms to higher quality ones and forcing a 1080 output regardless of the timeline resolution made the issue go away.

However when I rendered out the timeline un-scaled, at original UHD, the cross hatch pattern is still there on the output file.

This is just a small section from the bottom right enlarged to make it easier to see.

UM46K.jpg


Just curious, how did you take this screen shot? Screencap from a player, export from an edit system, etc?


EDIT: I exported the chair footage to UHD DNxHR HQX and then converted that to h.264 UHD and I see the crosshatch pattern in VLC. When I view it in After Effects, it's not there at 100%.

On a side note, I was able to provoke a cross hatch pattern on MY camera's footage in Resolve by switching the resize filter to "Optimize for Playback" and also "Bilinear" (which I had not done before because I've always been using the best quality settings) however, when I followed the same process - UHD DNxHR HQX to h.264 UHD, I can't see the crosshatch pattern. One thing to note though is that on my camera, the crosshatch doesn't look as prominent and it looks like grain/noise but if you look close, it's got a subtle crosshatch pattern to it. Very odd. This is at 1600 ISO though.

So now the questions are:

1. Why am I not seeing it on my camera when rendering to UHD/UHD h.264 and...
2. What do we trust? Our media players or the editing/grading software?

Most people will be viewing our stuff through traditional players so the fact that it shows up in Quicktime, VLC, etc is a big concern.
Last edited by PaulDelVecchio on Fri Sep 23, 2016 4:51 am, edited 3 times in total.
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Re: Cross Hatching Wont Go Away

PostFri Sep 23, 2016 4:37 am

I rendered the time line as a tiff sequence and saved out a cropped and 400% enlarged version from Photoshop.
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Re: Cross Hatching Wont Go Away

PostFri Sep 23, 2016 4:44 am

John Brawley wrote:
David Hessel wrote:15 years of experience using the same software for years working with all sizes and resolutions of files and never seeing this and now the footage off this camera displays it and it is suddenly a software scaling issue. Not likely.


What other cameras have you worked with that originate without an OLPF ? The do call them AA filters too. I wonder if that's the issue ?

JB


This could very well by the first, admittedly I am more experienced with the post side of things rather thank acquisition so I cannot say for sure. I suppose that could be the issue that is causing it, I kind of doubt it since it is such a regular grid structure and I would expect it to me more like aliasing from lack of an OLPF. Whatever the source it comes from the camera not the software processing it and it is a problem if you cannot shoot above 2K without fear that the image will be degraded by this artifact. It would be great to get a dng from a suspect camera so I can pull out a bayer image and see what a 4.6K raw image looks like before being debayered.
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Re: Cross Hatching Wont Go Away

PostFri Sep 23, 2016 4:48 am

Paul, thanks for the tip about using Sharper. The example you posted certainly looked better enabling Sharper. I've never turned that option on, but I think I should use it often.


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Re: Cross Hatching Wont Go Away

PostFri Sep 23, 2016 4:56 am

Ok so after further testing I concluded the following:

4.6k prores film footage "native file" viewed with either VLC/QT8 showes the crosshatch pattern:
Brought the footage into resolve, color corrected it and rendered at various timelines BELOW 4.6k (tried 4k DCI, UHD, 2kDCI, 1080p) - resulted in clean footage no signs of crosshatch (used VLC/QT8 to view footage).

UHD prores film footage "native file" showing crosshatch pattern with VLC/QT8:
Brought the footage into resolve, color corrected it and rendered at the same resolution timeline (UHD) resulted in crosshatch pattern on the output.(viewed with VLC/QT8)

I think it safe to say that if your "native file" shows crosshatch, as long as you process the footage at a lower resolution you are safe...

Also, I think I noticed that Resolve has a bug ... when my UHD footage processed on the same resolution timeline showed crosshatch pattern, I needed to shut down resolve without saving in order to start the procedure again otherwise I noticed that even if I process the footage at a lower resolution timeline it will render with the crosshatch pattern so by "resetting" Resolve I was able to produce cleaner footage upon rendering.

I need some sleep.
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Re: Cross Hatching Wont Go Away

PostFri Sep 23, 2016 5:03 am

PaulDelVecchio wrote:So now the questions are:

1. Why am I not seeing it on my camera when rendering to UHD/UHD h.264 and...
2. What do we trust? Our media players or the editing/grading software?

Most people will be viewing our stuff through traditional players so the fact that it shows up in Quicktime, VLC, etc is a big concern.


Good questions, if you can share a shot from your camera I will have a look and see if it is behaving differently.

I have noticed that at 100% the effect is fairly subtle unless you look closely but it is there. On playback it almost resembles regular noise. Zoom in more and you can see it clearly. I think this regular grid like pattern is exaggerated by the more real time scaling algorithms causing the affect to more pronounced when viewing the footage on a player that is down scaling it for display on a lower resolution monitor. I have been able to measure the pattern, they form boxes of lighter colored pixels that are 6 x 6 pixels in size.
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Re: Cross Hatching Wont Go Away

PostFri Sep 23, 2016 5:08 am

David Hessel wrote:
PaulDelVecchio wrote:So now the questions are:

1. Why am I not seeing it on my camera when rendering to UHD/UHD h.264 and...
2. What do we trust? Our media players or the editing/grading software?

Most people will be viewing our stuff through traditional players so the fact that it shows up in Quicktime, VLC, etc is a big concern.


Good questions, if you can share a shot from your camera I will have a look and see if it is behaving differently.

I have noticed that at 100% the effect is fairly subtle unless you look closely but it is there. On playback it almost resembles regular noise. Zoom in more and you can see it clearly. I think this regular grid like pattern is exaggerated by the more real time scaling algorithms causing the affect to more pronounced when viewing the footage on a player that is down scaling it for display on a lower resolution monitor. I have been able to measure the pattern, they form boxes of lighter colored pixels that are 6 x 6 pixels in size.


Yup. It is there. Saw that myself on my footage when enlarged to "actual size" on a UHD file.
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Re: Cross Hatching Wont Go Away

PostFri Sep 23, 2016 5:10 am

well at least if anyone who has this crosshatch pattern and wants to shoot UHD can get clean UHD timeline by shooting 4.6k and downscaling it to UHD timeline within resolve.
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Re: Cross Hatching Wont Go Away

PostFri Sep 23, 2016 7:52 am

PaulDelVecchio wrote:Most people will be viewing our stuff through traditional players so the fact that it shows up in Quicktime, VLC, etc is a big concern.


This is exactly the problem.

I shoot documentaries almost exclusively, and more than 90% of the time I'm hired to hand off ProRes files at the end of the shoot day. Most of my clients grade directly in their NLE, they do not use Resolve. If I shoot ProRes UHD files on my Ursa Mini 4.6, the cross hatch pattern shows up even in files that have been edited, graded and exported from Premiere and FCPX (I haven't tested Avid).

This is a serious problem. I can't hire my camera out for any ProRes UHD job that won't be running the footage through Resolve as part of the workflow. This is most of my gigs. Unless BMD can fix the issue, I've got a $5000 camera that was supposed to generate some income that now I'll only be able to use for personal projects and the rare documentary producer who actually gets their work graded in Resolve and won't mind seeing the cross hatch issue throughout their offline edit.

BMD markets their cameras to a large extent for their ability to shoot directly to ProRes files compatible with any NLE. I think the cross hatch issue makes that claim complete BS. "Compatible" files shouldn't need a trip through Resolve to render properly.

I've got an RMA arranged for my camera, but when I asked the BMD support staff handling my ticket whether it would eliminate the problem, their answer was that it would "improve" it. That doesn't inspire confidence that the issue will be fixed.

Hey BMD. Please confirm the official word: Can the cross hatch problem be completely eliminated in camera or not?
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Re: Cross Hatching Wont Go Away

PostFri Sep 23, 2016 8:01 am

Does anyone have a camera that DOES NOT show any signs of crosshatching? IF so, can you post a link to a raw prores clip at 1600ISO (with shadows in the scene) so we can inspect?
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Re: Cross Hatching Wont Go Away

PostFri Sep 23, 2016 1:00 pm

Jamie LeJeune wrote:
PaulDelVecchio wrote:
Hey BMD. Please confirm the official word: Can the cross hatch problem be completely eliminated in camera or not?


Yes... BMD?
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Cross Hatching Wont Go Away

PostFri Sep 23, 2016 3:13 pm

Clarification, if shooting in UHD and downscaling in Resolve removes the apparent crosshatch, can the same be achieved by downscaling in the camera? Use the full sensor 4.6K readout, but downscale in camera to record ProRes at UHD/HD or other 16:9 resolutions.

Remember 4.0 firmware allows that Sharpen setting that Paul is using in Resolve to remove the crosshatch.


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Re: Cross Hatching Wont Go Away

PostFri Sep 23, 2016 3:41 pm

rick.lang wrote:
Remember 4.0 firmware allows that Sharpen setting that Paul is using in Resolve to remove the crosshatch.


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I don't think it's the same thing but I'm not sure. I thought the sharpening done in camera is the same as the sharpening in the RAW tab in Resolve.
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Re: Cross Hatching Wont Go Away

PostFri Sep 23, 2016 4:08 pm

PaulDelVecchio wrote:
rick.lang wrote:
Remember 4.0 firmware allows that Sharpen setting that Paul is using in Resolve to remove the crosshatch.


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I don't think it's the same thing but I'm not sure. I thought the sharpening done in camera is the same as the sharpening in the RAW tab in Resolve.


Yea adding the sharpening in camera makes the cross hatching way worse
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Re: Cross Hatching Wont Go Away

PostFri Sep 23, 2016 4:09 pm

Thanks, Phillip. That was my original assumption.


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Re: Cross Hatching Wont Go Away

PostFri Sep 23, 2016 5:21 pm

rick.lang wrote:Clarification, if shooting in UHD and downscaling in Resolve removes the apparent crosshatch, can the same be achieved by downscaling in the camera? Use the full sensor 4.6K readout, but downscale in camera to record ProRes at UHD/HD or other 16:9 resolutions.


It's a good thought Rick.

In my testing, shooting full sensor and recording UHD ProRes results in cross hatching.

Shooting full sensor and recording HD ProRes does not result in cross hatching.

Shooting windowed UHD or HD ProRes results in cross hatching.

Other users have reported similar results.
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Re: Cross Hatching Wont Go Away

PostFri Sep 23, 2016 5:29 pm

Thanks, Jamie, I will watch out for that.

I'm mostly shooting 2K 16.9 now and I hope that will be good for the shoot this Sunday (pro bono but I need good results anyway as many people are going to view the results). I have rarely seen a problem on my camera when exposed well. Sunday will be a EXT DAY under mixed skies so need good shadows and highlights.


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Re: Cross Hatching Wont Go Away

PostFri Sep 23, 2016 7:45 pm

you can download a DNG of raw lossless 4.6k here:
https://spaces.hightail.com/receive/OCj9h

This is a screenshot of the DNG zoomed in at 400%
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Re: Cross Hatching Wont Go Away

PostFri Sep 23, 2016 9:26 pm

Thank you, I will have a look.
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Re: Cross Hatching Wont Go Away

PostFri Sep 23, 2016 10:33 pm

I am seeing something very interesting with the green channel. Can anyone confirm that the 4.6 uses the standard bayer pattern as below? I believe it does but I don't have any confirmation. Thanks.

R G
G B
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Re: Cross Hatching Wont Go Away

PostFri Sep 23, 2016 10:51 pm

Nevermind found it in metadata, it is

G B
R G
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Re: Cross Hatching Wont Go Away

PostSat Sep 24, 2016 2:16 am

rick.lang wrote:Thanks, Jamie, I will watch out for that.
I'm mostly shooting 2K 16.9 now and I hope that will be good for the shoot this Sunday (pro bono but I need good results anyway as many people are going to view the results). I have rarely seen a problem on my camera when exposed well. Sunday will be a EXT DAY under mixed skies so need good shadows and highlights.


Are you shooting 2K downscaled from the full sensor, or windowed 2K? On my camera, windowed 2K ProRes files also exhibit the cross hatching.
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Cross Hatching Wont Go Away

PostSat Sep 24, 2016 4:55 am

Jamie, on Sunday it's the Fujinon B4 zoom so that's 2K windowed. I'll test Saturday with ProRes and raw and see if one is better than the other. My guess is the ProRes will look better. My deliverable with be HD h.264 destined for the client's YouTube channel.

Any advice appreciated.


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Re: Cross Hatching Wont Go Away

PostSat Sep 24, 2016 10:57 am

I've written about it before in these threads, but I made a video so maybe more people find out about a possible solution and maybe a better permanent solution can be found. The scaling issue is just a symptom of the real problem. It seems it might be caused by an imbalance between the green channels on the bayer pattern sensor (source).


(best viewed in youtube's full quality, fullscreen on a 1080p monitor or better to see the two effects, if you're watching on a tablet or phone where you can't control youtube's settings, it will likely be difficult to see)

In the video I'm comparing two DNG:s, one original and one that's had its BayerGreenSplit parameter changed using CornerFix. The change is not visible in DaVinci Resolve since it doesn't support that particular parameter, but Adobe Camera Raw does.

There's an easier way than using CornerFix though, using ExifTool, http://www.sno.phy.queensu.ca/~phil/exiftool/.

To convert a whole DNG folder (example for Windows):

Code: Select all
"exiftool(-k).exe" -ifd0:bayergreensplit=10 "d:\Footage\2016-08-15\*.dng"

The value to use (in this case 10) would be individual to each camera i presume, I'm not an expert.
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Re: Cross Hatching Wont Go Away

PostSat Sep 24, 2016 1:59 pm

So I found something interesting which is also consistent with the green channel inbalance in the previous post.

So what I did was extract a bayer image from the dng provided. This image is black and white and has not been debayered so the bayer pattern still exists in the image.

Next I extracted each color channel, since red and blue are responsible for 1/4 the pixels the end up being 1/4 resolution at approximately 2.3K width.

The green channel is the same width as the red and blue images but double height since the green in a bayer pattern exists in every pixel row where red and blue exist in every other pixel row. For this camera it is

G B
R G

Here are the images, sorry I had to do compressed jpgs due to size restrictions.

UM-red.jpg
Red
UM-red.jpg (365.67 KiB) Viewed 19755 times

UM-green.jpg
Green
UM-green.jpg (799.76 KiB) Viewed 19755 times

UM-blue.jpg
Blue
UM-blue.jpg (321.63 KiB) Viewed 19755 times
Last edited by David Hessel on Wed Oct 05, 2016 9:19 pm, edited 1 time in total.
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Re: Cross Hatching Wont Go Away

PostSat Sep 24, 2016 2:03 pm

To confirm that every thing was correct I made a color image from these by scaling the green channel by 50% vertically and then in photoshop I copied the red image to the red channel, green image to green channel and blue image to blue channel. Here is the result.

UM-RGB.jpg
UM-RGB.jpg (309.99 KiB) Viewed 19753 times


As you can see the colors look correct as it should. The red and blue channels looked normal the green channel however looks like this.

UM-green-zoom.jpg
Green Zoom
UM-green-zoom.jpg (73.44 KiB) Viewed 19753 times


It appears to alternating rows of bright and dark pixels. It is possible that it is not only the green channel that is affected by these light and dark rows but since the red and blue channels only exist on every other row the effect cannot be seen in them. It seems it would be more likely that an entire row of pixels is lighter then the next entire row of pixels is darker and I have seen other evidence of this as well.
Last edited by David Hessel on Wed Oct 05, 2016 9:20 pm, edited 1 time in total.
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Re: Cross Hatching Wont Go Away

PostSat Sep 24, 2016 4:43 pm

This also show that there are significant differences between the two green pixels in the Bayer pattern.
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Re: Cross Hatching Wont Go Away

PostSun Sep 25, 2016 8:33 am

David Hessel wrote:This also show that there are significant differences between the two green pixels in the Bayer pattern.


Fascinating! Thank you David for doing these tests.

Are you saying there is a difference between the two sets of green pixels in the sensor hardware, or a difference in way the two sets of green pixels are being processed by the camera?

And what can be concluded from that difference?
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Re: Cross Hatching Wont Go Away

PostSun Sep 25, 2016 2:05 pm

All I can say I that in the dng posted by Eli there is a variation in the green channel. There is a lighter row followed by a darker row that repeats down the image. I cannot say what the cause is or if it is hardware or software.

What I meant from that statement is in the final dng on Bayer pattern of 4 pixels will have a fairly large different in the green pixels since they come from different rows. This is a green imbalance that can cause the grid pattern many are seeing. Someone else posted here suspecting that might be the problem which is were I first heard of it but it is a good candidate for what we are seeing.
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Re: Cross Hatching Wont Go Away

PostSun Sep 25, 2016 4:22 pm

Would LOVE to hear BMD's thoughts on all this......
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Re: Cross Hatching Might've Gone Away

PostMon Sep 26, 2016 9:25 pm

I received my UM 4.6k back from being RMA'd this morning and have run it through a series of tests... sharing all the results here.

Short story is that, upon first look I'm loving what they did. I'm not seeing any of the regular cross-hatching patterns on any of the 20 different tests I've run (both on firmware 3.0 and firmware 4b2).

My basic quick test is to bring the file up in quicktime and then scale it, looking for the "harmonics" that show the crosshatching artifact. On all of my previous footage this was the fastest and most reliable test.

Without getting into a huge post, I'm just going to give you dropbox links to various sets of files and you can see for yourselves. Of course I'm curious as to what everyone else thinks.

Firmware 3.x. - 6 tests. (raw 4.6k full, raw 4.6k windowed, etc as labeled in the screenshot files) Absolutely no changes of any kind applied to any of the tests.

1) https://www.dropbox.com/s/p2i5zvgklk9j3k7/v3%20screenshots.zip?dl=0 - This is a set of 1000% zoomed-in screenshots pulled from each of the six firmware 3.x tests, all inside of Resolve with the resolution of the timeline natively matching the resolution of the shot so there's no rescaling.

2) https://www.dropbox.com/s/hchvy691oxrfedj/UM46%20tests%20post%20fix%20-%20firmware%203.zip?dl=0 - Here are the 6 actual files, both raw and prores. They are labelled as they came out of camera so for you to know what each specific test is you'll have to listen to the audio track.


Firmware 4b2 - 14 tests. (raw 4.6k full, raw 4kDCI windowed, raw UHD windowed, etc as labeled in the screenshot files) Absolutely no changes of any kind applied to any of the tests.

1) https://www.dropbox.com/s/29rz5bggvkgfhex/v4b2%20screenshots.zip?dl=0 - This is a set of 1000% zoomed-in screenshots pulled from each of the 14 firmware 4b2 tests, all inside of Resolve with the resolution of the timeline natively matching the resolution of the shot so there's no rescaling.

2) https://www.dropbox.com/s/n5xxhmtia9l5r8y/UM46%20tests%20post%20fix%20-%20firmware%2042b.zip?dl=0 - Here are the 14 actual files, both raw and prores. They are labelled as they came out of camera so for you to know what each specific test is you'll have to listen to the audio track.

Every single one of these files passed my "harmonic artifacting" test and it seems to me as if the issue has been put to bed. I'm looking forward to hearing what y'all think.
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Re: Cross Hatching Wont Go Away

PostMon Sep 26, 2016 9:48 pm

Gary! Fantastic news! I hope we start to see all the cameras are like this, or that BM will RMA them and then return them like this! Thanks so much for your detailed tests and sharing.

I have read some wild theories about the magenta vignetting and this issue. At the very least they are probably both related to the green photosites, so I wonder if you'd mind sharing a test of that so we can see what your good sensor looks like under those conditions.

The test is a non compressed DNG of a white wall, hopefully somewhat evenly lit, a 35mm or 50 mm lens, Sigma 18-35 at 35 is best if you have it, and f/8. Post it here or in the magenta thread, if you are able to do it.

Thanks so much for sharing all this, it really helps to understand what's going on!
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Re: Cross Hatching Might've Gone Away

PostMon Sep 26, 2016 10:41 pm

Gary Yost wrote:I received my UM 4.6k back from being RMA'd this morning and have run it through a series of tests... sharing all the results here.

Short story is that, upon first look I'm loving what they did. I'm not seeing any of the regular cross-hatching patterns on any of the 20 different tests I've run (both on firmware 3.0 and firmware 4b2).

My basic quick test is to bring the file up in quicktime and then scale it, looking for the "harmonics" that show the crosshatching artifact. On all of my previous footage this was the fastest and most reliable test.

Without getting into a huge post, I'm just going to give you dropbox links to various sets of files and you can see for yourselves. Of course I'm curious as to what everyone else thinks.

Firmware 3.x. - 6 tests. (raw 4.6k full, raw 4.6k windowed, etc as labeled in the screenshot files) Absolutely no changes of any kind applied to any of the tests.

1) https://www.dropbox.com/s/p2i5zvgklk9j3k7/v3%20screenshots.zip?dl=0 - This is a set of 1000% zoomed-in screenshots pulled from each of the six firmware 3.x tests, all inside of Resolve with the resolution of the timeline natively matching the resolution of the shot so there's no rescaling.

2) https://www.dropbox.com/s/hchvy691oxrfedj/UM46%20tests%20post%20fix%20-%20firmware%203.zip?dl=0 - Here are the 6 actual files, both raw and prores. They are labelled as they came out of camera so for you to know what each specific test is you'll have to listen to the audio track.


Firmware 4b2 - 14 tests. (raw 4.6k full, raw 4kDCI windowed, raw UHD windowed, etc as labeled in the screenshot files) Absolutely no changes of any kind applied to any of the tests.

1) https://www.dropbox.com/s/29rz5bggvkgfhex/v4b2%20screenshots.zip?dl=0 - This is a set of 1000% zoomed-in screenshots pulled from each of the 14 firmware 4b2 tests, all inside of Resolve with the resolution of the timeline natively matching the resolution of the shot so there's no rescaling.

2) https://www.dropbox.com/s/n5xxhmtia9l5r8y/UM46%20tests%20post%20fix%20-%20firmware%2042b.zip?dl=0 - Here are the 14 actual files, both raw and prores. They are labelled as they came out of camera so for you to know what each specific test is you'll have to listen to the audio track.

Every single one of these files passed my "harmonic artifacting" test and it seems to me as if the issue has been put to bed. I'm looking forward to hearing what y'all think.


Hey Gary, yea I'm not seeing any Crosshatching like I would see in my footage either! What ISO did you shoot these at?
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Re: Cross Hatching Wont Go Away

PostMon Sep 26, 2016 11:02 pm

Kyle Gordon wrote:Gary! Fantastic news! I hope we start to see all the cameras are like this, or that BM will RMA them and then return them like this! Thanks so much for your detailed tests and sharing.

I have read some wild theories about the magenta vignetting and this issue. At the very least they are probably both related to the green photosites, so I wonder if you'd mind sharing a test of that so we can see what your good sensor looks like under those conditions.

The test is a non compressed DNG of a white wall, hopefully somewhat evenly lit, a 35mm or 50 mm lens, Sigma 18-35 at 35 is best if you have it, and f/8. Post it here or in the magenta thread, if you are able to do it.

Thanks so much for sharing all this, it really helps to understand what's going on!


Sure thing... will get to it as soon as I can, probably tomorrow. Right now I'm finally rigging up the camera to the Letus Helix... something I've wanted to do for awhile but needed to get the heavy duty baseplate and the special cable to run the UM off the Helix juice box.

Will get back to you mañana....
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Re: Cross Hatching Might've Gone Away

PostMon Sep 26, 2016 11:04 pm

Phillip Bergman wrote:Hey Gary, yea I'm not seeing any Crosshatching like I would see in my footage either! What ISO did you shoot these at?


All shot at 800 Sigma 18-35 at f5.6, 35mm. First set of tests (3.x firmware) with no nd, and then 0.6 for the second set of tests after it got brighter.
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Re: Cross Hatching Wont Go Away

PostTue Sep 27, 2016 2:53 am

Gary you rock, thank you.
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Re: Cross Hatching Wont Go Away

PostTue Sep 27, 2016 3:39 pm

Thanks Gary,
Based on viewing your clip I feel confident sending my unit in.

Thanks,

Eli.
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Re: Cross Hatching Wont Go Away

PostFri Sep 30, 2016 10:55 pm

So I just got my camera back from Blackmagic. I had hoped they would have given it the Gary treatment and gotten rid of the crosshatching, but instead they opted to just send me a new unit altogether, and this new unit has the same issue...though it seems to be slightly less noticeable than on my old unit. Frustrating thing is there's not word/notes/email from blackmagic explaining anything so it just feels like they just grab a camera off the shelf, don't bother to check if it has issues, and just send it out. So I don't know what to do now. I guess I just live with it until I can afford to buy a camera from a professional company. Sigh.
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Re: Cross Hatching Wont Go Away

PostSat Oct 01, 2016 2:12 am

I know it is a hassle but if you cannot return the camera keep doing RMA's until you get a good one. It is expensive to just eat the cost and BM should not be allowed to get away with this non-sense.
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Re: Cross Hatching Wont Go Away

PostSat Oct 01, 2016 3:29 am

I already emailed them about it and they responded pretty quickly offering another RMA so props to them for that, but I have a lot of shoots this month so i'll probably have to wait to send it back in until November. It's just frustrating having waited a year for this camera to come out in the first place, promising all these cool things, then getting rid of a lot what was promised (Global shutter, gyroscope, 160fps), and then releasing the camera 8 months late only to have horrible magenta issues and sensor problems that are still yet to be addressed. At this point I know I'm going RED for my next camera. I've tried to stick it out with blackmagic but I need an actual professional camera at this point.
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