Vertical Lines on under exposed dark areas

[Boygetslost]

Hey,

Does anyone have any advice on dealing with the vertical lines that appear in dark under exposed areas. Im trying to work with the noise floor of the 5d3 in 14 bit. So far I am handling/dealing with the chroma noise ok. But the vertical banding is very difficult to remove and if there a slight hint of it, really damages the sharpness when Youtube compresses it.

Is there anything I can do, I assume this is normal?

Has anyone got any advice with how to deal with this ?


https://ibb.co/zn4xXwd

(The lines are more noticeable in movement then in a still frame)


Thanks


5D3, 14 Bit uncompressed 1920 x 1080
Build: crop_rec_4k_mlv_snd_isogain_1x3_presets_2020Dec11

[Kharak]

What you are referring to is FPN, Fixed Pattern Noise.

Neat Video takes care of some of it.

Darkframe Averaging also removes some of it.

But in the end you are digging in the noise floor, i have in-house noise profiles that clean up the noise floor perfectly, except for the FPN, because the FPN is “detected” as part of the scene. I believe the FPN could be removed/interpolated in to the image again, with the right algorythm, because in most cases the FPN is a row of pixels being slightly under or overcharged compared to the neighbouring rows. But I am not capable of creating anything like that. I keep hoping Neat Video will add some kind of FPN remover, we will see.

So VFX it is, using Mocha if you really need to get rid of it.

And of course always add noise (Grain) back in to the image to dither the details and in some cases hide the FPN.

[Boygetslost]

Cheers  Kharak

I thought it was fixed pattern noise but I didn't want to just assume.

How do I dark frame average? I had a google search but that lead me down a rabbit hole.

Is there a specific point that the lines become apparent that I could look for in the scopes? Or some way of seeing a marker for it in any of the view assists?

[masc]

How do I dark frame average?

https://github.com/ilia3101/MLV-App/wiki#darkframe-subtraction

[wib]

I tested it and it's very efficient.

you have to record 10s of dark clip right after your shot if possible, with the same settings, as the sensor will generated the same noise patterns. then check what the guy does in the video below on how to use that dark clip.

[Boygetslost]

Thank you Wib!

That is literally the most informative video I have ever watched on the subject. Answered so many questions!!!


So the under exposed lines, is that normal to all 5d 3's or is it bad luck that I have the issue on mine?

[wib]

i have them appear sometimes when too much under exposed.

[Boygetslost]

Thank you, any advice for dealing with hot pixels, I seem to have quite a few?

[wib]

There is a tool to clone stamp them withinn MLV App and also in DR.

But also a good advise is to turn off and let cool you camera sometimes. The longer it is ON and recording, the hotter it will make the sensor, and produce noise.

[Boygetslost]

Thank you!