Ripple/wavy pattern in dark area

resolve technical issues related to use of Neat Video
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spatience
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Joined: Wed Jun 14, 2017 10:51 am

Ripple/wavy pattern in dark area

Post by spatience »

I have just upgraded to ver 4.5 and notice a marked improvement on my earlier version. However, I have noticed a ripple/wavy pattern or banding in a darker area but is not apparent when there's more light.

Do you have a suggestion how this can be avoided ?

Thanks
Stephen
NVTeam
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Post by NVTeam »

Is that something like the banding illustrated in this page?

Thank you,
Vlad
spatience
Posts: 7
Joined: Wed Jun 14, 2017 10:51 am

Post by spatience »

Hi Vlad,

No, the banding doesn't look like that you have linked to. I have instead provided 2 images which should give an idea:


http://www.stephenpatience.photography/ ... scura1.jpg

http://www.stephenpatience.photography/ ... scura2.jpg

Hoping you have a solution here.

Thanks
Stephen
NVTeam
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Post by NVTeam »

Hi Stephen,

Is this video from a real camera or is it a CG imagery?

Could you send a sample video (both original and also processed by Neat Video)? Please also create a test project with that original video, add Neat Video to that clip and make sure the problem is reproducible after rendering. We will open the project, render it, reproduce the problem and then analyze it.

Thank you,
Vlad
spatience
Posts: 7
Joined: Wed Jun 14, 2017 10:51 am

Post by spatience »

Hi Vlad,

The image you see is not CG. There is no actual movie file. It's a camera obscura of about 500 frames from a time-lapse using a DSLR. The image sequence sits in After Effects (AE).

I could render out a raw AVI file with no noise which will be around 50GB - probably too big. To maintain the best quality, I'd rather be working on the actual raw sequence of tiffs (as have done with astro time-lapses) rather than anything rendered. Maybe you want a part of the tiff sequence rendered as an AVI to work on which would be more manageable ??

To make the supplied image, I rendered about 10 or so frames as an AVI and then exported the Neat Video processed frames back out into tiffs from AE and then made a few jpgs from there.

I have provided an HD version from one shoot here:
https://www.dropbox.com/s/866n2jy4uamfx ... 2.mp4?dl=0

Let me know what more you may need.

Thanks
Stephen
NVTeam
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Post by NVTeam »

Hi Stephen,

Thank you for preparing a video clip. It seems to show some static concentric bands that are likely present everywhere but mostly visible in shadows. Is that what you are referring to?

Do you see those bands in original shots? Which image format is used by the DSLR to save those individual shots and what camera model is it? Could you post one of those original shots?

Thank you,
Vlad
spatience
Posts: 7
Joined: Wed Jun 14, 2017 10:51 am

Post by spatience »

Hi Vlad,

Yes, I agree, they are concentric like bands in the shadows. I don't see them in the originals files.

The image format is NEF from a Nikon D810. Here's a couple of NEF raw files:

https://www.dropbox.com/sh/docx527yx6g9 ... -OCMa?dl=0

Thanks
Stephen[/url]
NVTeam
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Post by NVTeam »

Hi Stephen,

Thank you. Yes, I also do not see those bands in the original images. Perhaps that problem depends on the RAW converter used or on the next steps in the AE workflow that create those bands.

For example, please check if the rendering bitdepth chosen in your AE project affects the results. Try to change it from 8 to 16 and 32 in AE to see if this helps.

If that doesn't help, please create a small test project with 15 frames (to keep the file size manageable), verify that the problem is reproducible and then upload that project with source clips. We will run it on our machines, reproduce the problem and determine its causes.

Thank you,
Vlad
spatience
Posts: 7
Joined: Wed Jun 14, 2017 10:51 am

Post by spatience »

Hi Vlad,

I have checked my worksflow. I import the NEFs into Lightroom and grade and colour correct etc in there working also with LRTimelapse software. I export them as TIFFs with no compression, 300 pixels per inch, 16bits, and sRGB colour, before importing in After Effects which is where I apply Neat Video. Having looked at the finished exported tiff, I see the patterns there.

I have given more thought to the issue and suspect it is more to do with a 'moire effect' where the D810 does not have a low pass filter or anti alias filter aimed at making images more sharper. With this filter in, the camera ever so slightly blurs these lines.

Having researched a fix, there are various ways in post production using tools either in Lightroom or After Effects, but these also interfere with luminosity it would seem.

Should I proceed with a 15 frame AVI movie file with no Neat Video applied ?

Thanks
Stephen
NVTeam
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Post by NVTeam »

> Having looked at the finished exported tiff, I see the patterns there.

Do you see the patters in earlier stages of the workflow? For example, in AE preview if you render a small part of the sequence right there, without exporting it? Also, do you see the patterns while still inside Neat Video window, in the Noise Filter Settings tab?

This should help to identify the point where the patterns originate and then either adjust that point to fix the problem or work around the problem in that point.

Vlad
spatience
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Joined: Wed Jun 14, 2017 10:51 am

Post by spatience »

Hi Vlad,

I have confirmed that the concentric circles are there both before and after Neat Video has been applied. Here are links to 2 screen dumps from After Effects.

Before
https://www.dropbox.com/s/1emdf2uv80ksc ... o.jpg?dl=0

After
https://www.dropbox.com/s/ttwp8eqj3tj3m ... o.jpg?dl=0

I'm more convinced this is moire but the question for me now is will Neat Video get rid of these, or should I be looking to something else before I apply Neat Video. I think the earlier.

Stephen
NVTeam
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Post by NVTeam »

Hi Stephen,

Could you try to use the original RAWs instead of converted TIFFs right in that AE project for a test? Perhaps the conversion somehow added those bands even before AE and using the original RAWs can help to avoid that. At least for a test to find out the source of those bands.

Thank you,
Vlad
spatience
Posts: 7
Joined: Wed Jun 14, 2017 10:51 am

Post by spatience »

Hi Vlad,

I have done what you suggested and imported the raw NEF file directly into AE. At this stage, Adobe Bridge kicks in as a means to edit before it goes onto the timeline.

Looking at the images though, I notice a light ring which sometimes shows on the image due to the fact that it is very ashperical. I suspect that is the cause of my problem. I checked another lens from another camera I had set up and it did not have the issues.

Bottom line - I need to re-shoot my scene but choose a different lens.

Thanks for your help.
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