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Moire-Aliasing in Komodo

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Marko Alonso

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Has anyone noticed a tendency of the komodo to produce aliasing-moire?
I noticed it first with some small detail, and it becomes more apparent with a focus chart. Switching in Davinci the decode quality to full res. premium helped quite a bit, but there is still some. Any ideas on what other settings to adjust?

focus chart:
https://drive.google.com/file/d/1eGdXenOZiRQRxsgIKH1OPIk5S8qoyO6s/view?usp=sharing


Recording settings/specs:
Zeiss Standard 50mm @f2.8
172.8 shutter
6K MQ
23.98
800 iso


Davinci settings:
Full Res. Premium
Bit depth 16
Color science IPP2
Color Space RedwidegamutRGB
Gamma Curve Log3G10
with LUT applied

Thanks,

Marko Alonso
 
Ok, and hear me out.... the technical reasoning is beyond the time I have right now, but you might actually be seeing a lens artifact accentuated by the chart more than aliasing-moire. And of course it could be both things at the same time, moire and a form of fringing. Which specific chart details are you seeing the moire-aliasing? I'm definitely not saying that Komodo doesn't moire at times, but my eye sees subtle lens related issues more than clearly moire issues in the video.

I could be crazy though! :)
 
Is that video a 100% crop of the 6K material? What's the scaling algorithm used?
 
I haven't noticed any on a recent commercial shot on Komodo (not out yet, waiting for post production). Was using Arri UP, 6K HD mostly @2.8. Did you check another lens? This does seem to suffer heavily from CA.

Also there's a post about CA and Komodo. Things are rather related, search the forum. Might be due to the OLPF used in Komodo
 
There could be some fringing since those lenses are old, thought I was stopped down, and tried other shots stopped down even further, and tried other lenses (a canon zoom) and had similar issues. Ive heard that with RED you can have some artifacts when you are not shooting at full quality (6k, HQ in the case of the Komodo), since the image is being compressed more.
 
Could you send some seconds of the R3D?
I see some optical problems (green/pink shift on the focus pull)
I don't think it's due to a compression artefact.
 
Patrick Tresch said:
Could you send some seconds of the R3D?
I see some optical problems (green/pink shift on the focus pull)
I don't think it's due to a compression artefact.
Click to expand...

Second that, it's hard to know the reasons without having the source file.
 
I could be wrong, but this just seem like extreme Longitudinal Chromatic Aberration. (LOCA) It's consistently switching between green and purple, and the shift when you rack focus is really dramatic, which is pretty much what LOCA looks like, lol. It seems like the LOCA is just bad enough to draw a lot of attention to the fine areas. The added color comes off as moire, due to quickly shifting colors, but it's not. Try it on lower contrast, finer materials, not a pure black/white test chart.

I haven't seen any moire issues with this camera, even in the most extreme situations. (filming a phone screen, fine pattern cloths, etc) It's sharp, but the new OLPF seems to be doing a great job in that regard.

That said, this is some STRONG LOCA. This is just anecdotal, but I seem to notice more LOCA on the Komodo than I have on other cameras. I don't know if this is just me noticing it due to the better resolution/color detail, color profile differences, pixel peeping, or if it's actually more significant than other cameras, but I definitely have had moments where it's VERY noticeable. It's never enough to ever actually risk making a shot unusable, but enough to bug me.
 
Perhaps the global shutter "freezes" the LOCA artifact, making it easier to discern.

IAC, putting "Moire-aliasing in Komodo" as the thread title strikes me as unfair shade since the camera/sensor/OLPF is not the culprit.

Cheers - #19
 
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