Premiere render order magic and mysteries - HELP!
Shooting 4k Arri Mini ProRes.
I throw clips on 1080 timeline, and they come in at 50% scale as expected. I scale to 100% for tighter shot. Export 1080. No problem. I have not asked Premiere to create new pixels because I am at 100% of the source.
I pop clips on 4k timeline. They come in at 100% as expected. I scale to 200% for a tighter shot. NEST in 1080 master timeline and scale to 50%. Export 1080. Unexpected weirdness ensues.
With "Render at Maximum Quality" ON, the two versions are pixel-for-pixel identical.
With "Render at Maximum Quality" OFF, the second is slightly blurry.
I expected Scenario 2 to be a little blurrier because of the render order... Mathematically, the operations I did should result in the precisely the same image, but in the second scenario, Premiere is scaling beyond 100% (requiring it to create new pixels) before it scales back down to 1080. In AfterEffects, Scenario 2 WOULD result in a blurrier image, unless "Continuosly Rasterize" is checked.
Basically, Premiere seems immune to the hazards of scaling up and back down!
1) Is "Render at Maximum Quality" like "Continuously Rasterize"?
2) What is Premiere's render order?
3) Assuming that Premiere is smart enough to do the various calculations and preserve resolution, always attempting to use the maximum pixels from the source file--what kind of nesting would make that impossible? For example, if I edited in 4k and scaled footage past 100%, then put effects and masks on it, then nested back to 1080 and scale to 50% (meaning that there would be plenty pixels for an equivalent scale of the source footage at less than 100%)--wouldn't Premiere be forced to render somewhere along the line and therefore preclude it from always going to the source footage pixels?
I hope that last question makes sense!
One of my colleagues loves to edit in 4k, even though our output is always 1080. I tell him that it's better to edit in 1080 because that way you can crop and move around your footage, because it's easier to keep an eye on your scale and make sure you don't go over 100%.
"But," he says, "as long as I don't go over 200% scale on my 4k timeline, I should be okay because when I render to 1080, Premiere should be smart enough to calculate the RELATIVE scale of the source footage. As long as I'm under 200%, the relative scale on a 1080 output will be under 100%."
Mathematically, this is true. But I couldn't believe Premiere would be able to circumvent the immutable laws of render order!
Any insights would be very helpful!
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