6D ML RAW producing rainbow color speckles with specific lenses

[Jaysenedwinward]

I have searched the forum exhaustively and tried every solution I could think of but I fold. I now come to you for help.



I am finally up to speed with the whole RAW video workflow. The only thing holding me back is that I cannot for the life of me figure out why my video sometimes comes out like the above picture. It only happens when I use the 24-105mm L and only sometimes. In the photo above you can see weird rainbow colored squares but even in the actual moving footage, everything looks pixelated like an old Super Nintendo game.

Below I have a screengrab taken with the same lens and camera.... 4 seconds later in the clip.



No squares or rainbow color gunk and even when I pan back to the water (I suspected that it was moire) it didn't happen again. This also never happens with my 50mm f/1.8 nor does it occur with my 135mm f/2 L.

My settings are:

MLV Raw 1536x654
Aspect Ratio 2.35:1
Shutter 50
Dual Iso
MLV_Snd

I rip using MLV2DNG

I bring the footage to Davinci Lite or Premiere and it doesn't matter. It still looks terrible before I touch any settings.

[ddelreal]

Yeah, the 6D is known for this. I have a couple of 6D bodies and know your pain. It's really bad with my 28-75 2.8 Tamron. But like you, not bad at all with my 50mm 1.4, 85mm 1.8 or even my 70-200 2.8. I think it has a lot to do with far focus, wide shots with lots of detail and where everything is in focus. I'm still trying to get around this too. As mentioned in another thread, I tried the Mosaic Engineering VAF filter. It works pretty well but I sent mine back because we take stills too and it's too cumbersome to install/uninstall often. I'm trying various lens filter ideas including DIY - clear lens filter with some clear nail polish drops. It helps but not sure I'm liking it though. You could always try the 5x (actually 3x) zoom to help, but then you need to go wider on your lens.

[Levas]

It's aliasing from the 6d and bad debayering from your raw editor. (DaVinci debayering is not that good for the lineskipping Canon raw video)

It happens more when you have supersharp lens conditions. From f8.0 to f11 most lenses are at their best, go to f16 and they get a little softer.
Or shoot wide open (like f1.8, f2.0 or f2.8, depending on the max aperture of your lens).

What also works, is using another raw editor. I use photo editing software RawTherapee (opensource and free) for my raw DNG's.
http://www.magiclantern.fm/forum/index.php?topic=3904.msg123338#msg123338

I export the DNG's to TIFF and impport the TIFF sequence in DaVinci Lite

[Walter Schulz]

Seeing those artifacts "Dual ISO" comes to mind. Scenes with harsh contrast (as in rather dark twigs against highlighted/blown background) are prone to it. Please redo test using crop mode without Dual-ISO.

[Levas]

These artifacts are not from using dual iso.
These artififacts happen all the time in DaVinci Resolve in combination with Canon ML raw, especially with sharp (wide angle) lenses...
Seen them a lot with my Samyang 14mm on the 6d.
Shoot wide open or close down beyond f11.

[ddelreal]

It's not just Resolve. I shoot wide all the time, it's the wide angle lenses with everything in focus. Aliasing and Moire are plentiful in that situation.

[Jaysenedwinward]

Thank you so much for the help guys.

You were dead right. The 6D while using a really wide angle looks terrible like this every time no matter how I tried to debayer. =(

I am very upset with my 6D purchase at this point and I think I am finally ready to just sell it and get something else. I have a bunch of Canon lenses so i guess I'm stuck with Canon at this point. I've heard the 5D does not suffer from this what so ever. True?

Or should I just go for the Blackmagic 4k everyone is gushing on and on about?

[Walter Schulz]

You may want to try crop mode or FAV in full frame mode. In full frame mode 6D will use line skipping prone to aliasing. All ML supported cams share this problem but 5D3. 5D3 is the only ML supported cam using pixel binning. 7D2 is told to do so, too (but I have no reliable source yet).
Or - as told before - use full frame with FAV. Crop mode will not use line skipping. Con: Crop as in virtual teleconverter. You will loose FOV.
And all of above will not change 6D's limited SD card bandwidth.

[Jaysenedwinward]

I have not tried the FAV or cropped mode yet. I will have to look into how to do those. I am a ML noob.

I do appreciate just how amazingly helpful everyone here is. I hesitated to post for so long because I wanted to make sure I tried everything I knew beforehand but you guys have given me some things to try.

[Walter Schulz]

Press zoom button to enter crop mode.

[Mehmet Kozal]

I used to get that kind of images all the time with my 650D whenever I didn't turn "crop mode" option on. VAF filter solved this problem for me, which I think is necessary when you film in raw [except the 5D MarkIII]. That's my experience.

[ddelreal]

Crop mode works well for me and has fixed a lot of this issue. Just need a really wide lens though...

[DeafEyeJedi]

Try a 8-16mm or at least in that range to make of doable with 3x crop mode...

[keepersdungeon]

Yeah I'm having the same problem now. Apparently raw therapee works well with moire better than LR.

[keepersdungeon]

Actually raw therapee works great, still have some moire but got rid of all the rainbow colors and even had better details from the horizontal lines on the window. Thanks @Levas. I used 1600 resolution, I think I will be even better at 1728

[ddelreal]

I went ahead and reordered the Mosaic Engineering 6D-VAF, can't do crop mode all the time...

[keepersdungeon]

Hmm I don't know I heard that it's not that gd for photos and as I take photos with my 6d as well it's not that practical to remove it and put it back every time... 

[ddelreal]

Yeah, it can be cumbersome which is why I returned the first one but in the long run I can't afford new bodies just yet and outside of crop mode there isn't really any other way to combat moire and aliasing on the 6D. We take photos with our 6D bodies too, just have to take the time to remove the filter when switching from video to pictures.

[Levas]

@Keepersdungeon,  RawTherapee makes raw video work for me 
But all other programs that could perform AMAZE or LMMSE debayering work probably just as good (but there aren't that many  )

If you have wide angle shots at small apertures like F8 or F11, so everything is almost in focus, you must try the microcontrast settings in the sharpening tab in RawTherapee.

Sharpening tab ->microcontrast -> Enable -> Enable 3x3 matrix instead of 5x5 -> push quantity to 80
Works really good with shots with lot's of tree leaves, meadows and stuff.

(For normal sharpening (unsharp mask) I use most of the times a amount of 100, or I turn it off, way better than standard settings with 250 amount of sharpening.)

[keepersdungeon]

@Keepersdungeon,  RawTherapee makes raw video work for me 
But all other programs that could perform AMAZE or LMMSE debayering work probably just as good (but there aren't that many  )

If you have wide angle shots at small apertures like F8 or F11, so everything is almost in focus, you must try the microcontrast settings in the sharpening tab in RawTherapee.

Sharpening tab ->microcontrast -> Enable -> Enable 3x3 matrix instead of 5x5 -> push quantity to 80
Works really good with shots with lot's of tree leaves, meadows and stuff.

(For normal sharpening (unsharp mask) I use most of the times a amount of 100, or I turn it off, way better than standard settings with 250 amount of sharpening.)

Yeah exactly!
And thanks again for the sharpening tips, I'll give that a try tonight.
If u don't mind me asking, is it better to shoot at 1728 or 1600 for the aliasing and moire? Coz at some forums they say lower is better as it's more blurred but for aliasing isn't it better to have higher res?

[Levas]

Aliasing is due to the lineskipping sensor, lower resolution won't help for that, it's still skipping lines.
A softer lens, with lower 'resolution' could help, so probably crappy old lenses are best for video

But in this case more resolution is better.
Especially if you upscale to 1920 wide resolution.
1600 to 1920 is 20% upscaling (so the pixels/areas where the aliasing is happening become 20% bigger too)
1728 to 1920 is 11% upscaling...

So the more upscaling you need, the more obvious the aliasing becomes.

Edit, Davinci Resolve lite does a great job upscaling, it has some specific settings for upscaling.

[keepersdungeon]

Aliasing is due to the lineskipping sensor, lower resolution won't help for that, it's still skipping lines.
A softer lens, with lower 'resolution' could help, so probably crappy old lenses are best for video [emoji14]

But in this case more resolution is better.
Especially if you upscale to 1920 wide resolution.
1600 to 1920 is 20% upscaling (so the pixels/areas where the aliasing is happening become 20% bigger too)
1728 to 1920 is 11% upscaling...

So the more upscaling you need, the more obvious the aliasing becomes.

Edit, Davinci Resolve lite does a great job upscaling, it has some specific settings for upscaling.

Ok great thanks again for ur help.
What I did and helped a bit is I resized my 1600 raw images to 4k then resized them back to 1080p it helped a bit but not that clean.

[KelvinK]

Not agree about upscaling in Resolve. I tried same file with upscale in LR and Resolve. LR gives less visible aliasing.
In Resolve in delivery tab I set use the best quaility.

Too bad you can't upscale in LR and save it as DNG or I did't find the way. Only tiffs/jpgs.

[KelvinK]

Also LR automaticaly removes some hot pixels, but again it can't be saved as DNG, so worthless.

[Levas]

  Never tried upscaling in LR for raw video because of the bad debayering.
But I can load the TIFFs, I export with RawTherapee, in LightRoom and upscale it.
Hmm I'll test that against upscaling the TIFFs in DaVinci

Edit: RawTherapee has also an option to remove hot pixels