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circle of confusion - IMAX / RED


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#1 sarah cuming

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Posted 19 May 2010 - 06:57 AM

Am pulling focus on RED one cam, at 4k. This film may end up blown up to IMAX . Does any one know what Circle of Confusion I should work to?

I generally use PCAm on the i-phone, but its at the menders!


Thanks,

Sarah
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#2 Chris Keth

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Posted 19 May 2010 - 11:37 AM

Am pulling focus on RED one cam, at 4k. This film may end up blown up to IMAX . Does any one know what Circle of Confusion I should work to?

I generally use PCAm on the i-phone, but its at the menders!


Thanks,

Sarah


I normally work 4k red to a CoC of .00075". Since you may be going to imax, you might go a bit tighter to .0005".
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#3 Chris Durham

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Posted 04 August 2010 - 01:37 PM

Hey Chris, I'm just wondering why you use .00075" for 4K as opposed to .001" which I believe a lot of people use for S35. If I understand correctly resolution shouldn't have so much to do with things as format with consideration also given to projection (which is why I could see giving a smaller circle of confusion for IMAX which, but for the larger projection, should have a larger acceptable CoC). Is it to accommodate for pixel pitch? Just wondering. I use smaller than .001" myself but that's basically to make sure my calculations are conservative.
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#4 John Sprung

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Posted 04 August 2010 - 02:24 PM

The important thing here is that Circle of Confusion is a subjective decision -- there's no absolute right answer. So, the right approach is to shoot a diagonal newspaper test and look at it real big on a good 4K projector. Ideally, the DP would look at that test and make the decision.




-- J.S.
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