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ProResHQ and the Broadcast Safe filter
I’m running FCP v6.06 on Leopard.
I’ve been checking a SD ProResHQ project for Luma overs. I get occasional luma warnings on the Tektronix WFM 700 scope. When I do, I can apply the Broadcast Safe filter (the default is enough to to clamp the waveform below 700 mv and eliminate the warning). This requires a render, and when I do, the overs come back and warning returns. The act of rendering, breaks the clamp that was working great before rendering.
If I export that same clip as 10bit uncompressed, drag it onto the timeline and apply the Broadcast Safe filter and render, the clamp works as expected. There is something about ProResHQ that is not rendering correctly.
I do notice a slight gamma shift with the rendered 10bit uncompressed clip, but its legal.
Any insight into this?
STeve
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3 Replies
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What kind of footage is in the SD sequence?
Are you rendering in “High Precision” ?
rafael -
You should use a ProcAmp or Levels filter for this, and manually adjust the whites till they read safe on your scope.
Arnie
Post production is not an afterthought!
https://www.arniepix.com/ -
I now believe that its not so much of a ProRes problem as it is that the original clip has a scale value in the motion tab. Baking it out to uncompressed flattened the scale. It seems that the Broadcast safe plug-in breaks with any scale or distortion (as in pixel aspect ratio) changes. Nesting the scaled clip and applying the Broadcast safe filter to the nest seems to work great.
Thanks for the heads up on the Proc Amp filter. Occasionally I get superblack luma errors that seem to punch thru even the Extremely Conservative setting of the Broadcast Safe filter applied to a nest. Following it with the Proc Amp filter at its default setting cleans this up without raising the average floor of the blacks (like the Levels filter will).
STeve
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