Workaround for Fixed Noise Pattern (Vertical Lines) in 5Diii Raw?

QuickHitRecord

QuickHitRecord

Veteran
How are people getting around the fixed noise pattern in 5Diii raw footage? I've worked with three different Mac-based conversion apps (RawMagic 1.12, MLRawViewer, and Recursive) that supposedly have "vertical stripe correction" built in, but upon running a test, none of them did any better than a conversion app without vertical stripe correction (RawMagic 1.12 with Vertical Stripe Correction box unchecked). I've looked on the ML boards and posted there as well, but I still haven't found a workable solution. It's a big problem because I have seen FPN show up in footage at ISOs as low as 400. What am I missing?
 
That's strange. I only got vertical lines at iso 3200. Are you underexposing a lot?
FWIW, I got rid of them with NeatVideo using temporal noise reduction; spatial NR doesn't seem to be able to handle them.
 
Can you show a screenshot with this problem. I have been shooting RAW now for months and I haven't had any problems with this. I use MLV Converter 1.9.2... I'm running the latest 1.2.3ML 21st June.
 
I think I'm exposing properly. Let me put up some images for context.

First, a lens-cap ISO test from my 5Diii shooting MLV raw (boosted exposure for illustration purposes -- this is probably old news to most of you):

5D_Raw_ISO_zpsb02b479e.jpg


Now, here's what ISO 800 looks like without vertical stripe correction (again, with an exposure boost):

No_VSC_zpsc47fd1ac.png


And with vertical stripe correction:

VSC_zpsd8e075ab.png


I can flip between and preview the first DNG of each export on my desktop and not see any difference at all, hence my concern that "vertical stripe correction" is not actually doing anything.

Lastly, here's a grab of a clip shot at 400 ISO, in Rec 709 with no LUTs. Applying FilmConvert really does a number on my footage, especially blues and reds. You may have to save these to your desktop and view them at full size to see what I'm talking about, but keep your eye on the blue patch. Notice that FC 'Film Grain' is dialed all the way to 0.

Without FilmConvert:

ScreenShot2014-07-07at83110PM_zps6bba46be.png


With FilmConvert:

ScreenShot2014-07-07at83118PM_zps60453413.png


And I do realize that there is a luminance boost going on there, but that's a LOT of blocky noise. I feel like I've got to push the footage around much more than that to get that kind of noise. Maybe this is a separate FilmConvert issue, or maybe I am missing something.

Either way, I appreciate any advice.
 
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Your images look as expected in terms of noise. My experience is that ML raw needs to be overexposed (relative to in-camera spot metering) with around half a stop. I guess the camera is pushing the signal up in processing to cover for this when shooting non-raw. Following this rule leads to nice clean footage in my experience, and I've only noticed the vertical noise appears objectionable at iso 3200 (I've never shot above 3200). There are traces of it in some 1600 shots but they disappear after very light NR, so it's a non-issue at this iso for me.

If I were to use this camera now I would treat it as an iso 1600 camera max. OR, make sure the iso 3200 shots are well fed with light.

FilmConvert compresses and stretches various parts of the color space - as does any film lut - and this surely will make noise stand out more. It's inevitable because film luts can be very specific on the regions they pull and push, and any color space compression means there is an expansion happening somewhere, which in turn accentuates noise. In any case, you should probably denoise before applying FC. You can also try ETTR, or simply overexpose consistently (that's what I did).
 
Thanks, cpc.

I did a little test based on your advice and used the ETTR hint in the raw histogram as a guide. From BMD color space, I applied VisionColor's VisionLog LUT (there's a mouthful), added another node in which I did some exposure and contrast adjustments, and a final node for FilmConvert (in the absence of a VisionLog source, the BMCC Film source seems to work well here). The result was the cleanest-looking 1600 ISO footage I have gotten out of my 5D yet!
 
This is the same FPN that one gets when shooting raw stills as well. h.264 compression smooths FPN as does jpeg compression (you can see this by examining jpeg stills versus raw stills).

I've shot raw video at up to 6400 while starving the camera for light with very usable results provided I used noise reduction (Neat Video). Noise reduction and a touch of sharpening is needed when shooting in raw.
 
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