Author Topic: Aliasing and Moire flicker on Dual ISO videos  (Read 9689 times)

kidfob

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Aliasing and Moire flicker on Dual ISO videos
« on: July 19, 2015, 07:08:06 AM »
Hello all. Im experiencing aliasing and moire on my dual iso videos in areas with fine detail.

I've tried to work around this by using the 3x zoom and 2560x1090 video resolution, but this doesnt seem to help much.

Any ideas?

Example video here:
http://www.mentatduke.com/videos/AliasingExample.m4v

Thanks

DeafEyeJedi

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Re: Aliasing and Moire flicker on Dual ISO videos
« Reply #1 on: July 19, 2015, 07:53:17 AM »
Link's broken?
5D3.113 | 5D3.123 | EOSM.203 | 7D.203 | 70D.112 | 100D.101 | EOSM2.* | 50D.109

kidfob

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Re: Aliasing and Moire flicker on Dual ISO videos
« Reply #2 on: July 19, 2015, 09:17:44 AM »
Right click and save as

DeafEyeJedi

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Re: Aliasing and Moire flicker on Dual ISO videos
« Reply #3 on: July 19, 2015, 09:28:11 AM »
5D3.113 | 5D3.123 | EOSM.203 | 7D.203 | 70D.112 | 100D.101 | EOSM2.* | 50D.109

kidfob

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Re: Aliasing and Moire flicker on Dual ISO videos
« Reply #4 on: July 19, 2015, 07:39:16 PM »
YouTube link. Watch as original/1440p:

dubzeebass

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Re: Aliasing and Moire flicker on Dual ISO videos
« Reply #5 on: July 19, 2015, 09:47:19 PM »
Danne figured out how to reduce it.

Danne

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Re: Aliasing and Moire flicker on Dual ISO videos
« Reply #6 on: July 20, 2015, 12:20:02 AM »
I,d say you need a 5d mark 3 and film in 3xcrop mode. Also reduce fringing if needed in ACR.
If you want to obtain around 20mm wideangle in 3x crop mode you can go down this route.
http://www.magiclantern.fm/forum/index.php?topic=12796.msg127357#msg127357

kidfob

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Re: Aliasing and Moire flicker on Dual ISO videos
« Reply #7 on: July 20, 2015, 12:53:15 AM »
Yes I am indeed using a 5d Mark 3 and shooting in 3x crop. I havent tried reduce fringing since i am using lightroom.

I am using a Tokina 11-16mm in addition to 3x crop.

Any other ideas?

Thanks!

kidfob

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Re: Aliasing and Moire flicker on Dual ISO videos
« Reply #8 on: July 20, 2015, 10:21:36 PM »
Just to follow up, I see basically ZERO moire or aliasing in the below video. What gives?:

THIS video had a LOT of aliasing however. Event with the 3x zoom and 2.5k:

Why the difference?

Danne

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Re: Aliasing and Moire flicker on Dual ISO videos
« Reply #9 on: July 20, 2015, 11:30:28 PM »
Both my videos.
 The one full with moire is done in regular mode and in an environment which usually produce aliasing. Blinds and lines on the wall.

The 2,5k videos are more like dual iso still photos. 3x crop mode gives 1:1 pixel. Also what type of scene and even what f-stop used will produce more or less artefacts. Even 3x crop wont give totally aliasing free files.

kidfob

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Re: Aliasing and Moire flicker on Dual ISO videos
« Reply #10 on: July 21, 2015, 06:33:04 AM »
Interesting. Didnt know about fstop affecting things. What would you say is an ideal fstop?

I'm using 3x crop with 1:1 pixel ratio also.

Thanks

Danne

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Re: Aliasing and Moire flicker on Dual ISO videos
« Reply #11 on: July 21, 2015, 09:10:44 PM »
Well. Fstop 2.8 could lessen aliasing effect as it would tend to soften background thus alson soften aliasing effect.
All deprnds on what you are trying to achieve. If you film a lot that gives yoj aliasing you could also try refining HDR filming since this will not give as much artefacts as dual iso. Of course ghosting could be a problem.

DeafEyeJedi

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Re: Aliasing and Moire flicker on Dual ISO videos
« Reply #12 on: July 22, 2015, 10:12:41 AM »
Here's an example... this was shot in non-crop mode on 16-35II @ 2.8 with a Circular Polarizer Filter on it to help compensate for the exposure in Dual-ISO (100/1600) while keeping it wide open in order to try and minimize Aliasing/Moire effect as well as @Danne was mentioning earlier.



It's not a perfect world but the Pro's definitely outweigh the Con's in there, doncha think?

Yes, I know it could have been better if I had shot this in crop-mode but hey I thrive living on the edges.
5D3.113 | 5D3.123 | EOSM.203 | 7D.203 | 70D.112 | 100D.101 | EOSM2.* | 50D.109

kidfob

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Re: Aliasing and Moire flicker on Dual ISO videos
« Reply #13 on: July 22, 2015, 11:31:51 PM »
Thanks for the feedback guys!

I'll do more research on this...