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Moire or aliasing?


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#1 Tiago Pimentel

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Posted 04 March 2018 - 09:19 AM

Guys,

Watch the tree branches. Would you say this is moire or aliasing issues from scaling down 4.6k footage to hd? And what would be the best way to avoid this?



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#2 Philip Reinhold

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Posted 04 March 2018 - 09:40 AM

I think the best way to avoid moire & aliasing is by using cameras with optical anti aliasing filters. I´ve no glue about post-production solvings but im sure there are some ways which can reduce this a bit - like chroma noise reductions?… however you´ll lose detail resolution.

 

Most professional digital cine cameras by arri, red & sony have internal olpf filters to solve that issue.

Since you said 4.6k - i guess you´re using a Blackmagic Ursa camera right?

 

They don´t have an internal lowpass Filter. But there are good 3rd party options for it which are worth their money (especially if you like to shoot in portugal with all the beautiful pavings, tiles & details ;-) ): http://www.mosaiceng...f/bm/umpro.html


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#3 Tiago Pimentel

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Posted 04 March 2018 - 11:44 AM

Thanks Philip. I've had my eye on that olpf for a while. My only issue is that i don't get moire on clothes like most people complain. That seems like aliasing due to some bad downscaling. I usually shoot in 4.6k raw and then edit and export in a 1080p timeline in Resolve. Maybe I'm doing something wrong.

I'm wondering if a olpf would prevent it from happening again and what is the tradeoff regarding overall sharpness...

Edited by Tiago Pimentel, 04 March 2018 - 11:47 AM.

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