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From: Jim Curtis <jpcurtis@me.com>
Subject: MB Looks head-scratcher
Date: Wed, 08 Aug 2012 10:28:12 -0500
Message-id: <353CA474-E840-4A1B-8006-5F6CA4E93C83@me.com>
To: After Effects List <AE-List@media-motion.tv>

Sorry, this is a Pr issue.  I'm posting here because I wonder why it's not an Ae issue.  Let me explain.

I'm getting these little crosses in zero black areas using Magic Bullet Looks on an Adjustment Layer.  

Here's a screen grab:
http://jamesphilipcurtis.com/public/Screen%20Shot%202012-08-08%20at%209.54.15%20AM.png

I'm getting this in Pr 601, MacPro3,1, 10.7.4, Quadro 4000.  The footage is ProRes4444 recorded from Arri+Cinedeck


This is some interaction with the Pr Levels effect on each clip, where I've taken the linear footage, and expanded the black (and white) levels to 0-100.

Turning off GPU in Looks prefs gets rid of them, but then rendering takes 10x as long.  I pasted my timeline from Pr into Ae.  Applied MBL to an Adjustment Layer, and the problem does not repeat in Ae.

I deleted the first instance of MBL in Pr, and applied a fresh Looks setting.  The crosses come back, but much tinier, even with no changes made in the MBL GUI.

I tried trashing Looks prefs, Pr prefs, reboot, reinstalled CUDA and nVidia card drivers.  This only started recently after using Looks with the same setup ever since CS6 came out.

I have discovered a workaround, but it's not perfect.  If I set each instance of the (RGB) Black Output Level on the source clips Levels Effect to 1 instead of 0, the crosses go away.  

I surmise this is perhaps a sub-black warning in Looks?  I'm wondering why I haven't seen it before, and why I don't see it in Ae, even if I force the black in the source clip to less than zero, followed by MBL.

I believe that Pr doesn't allow sub-black, but Ae does.  This may be why I can't repeat this issue in Ae.

Thanks,
Jim C.


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