I am editing 4K RED footage frame size 4096 x 2160 and my Preview frame size is set at 1919 x 1011. When i render my previews the aspect changes and the picture gets slightly squished resulting in a black line along the bottom. I can't seem to tweak the Preview frame size settings as they are locked together. Is this something I have to deal with until final master render out?
Well how 'bout that.
The problem I see is that the preview resolution isn't evenly divisible by 8, one of the cardinal rules when dealing with MPEG. This is likely because your original footage also has an odd frame size, meaning those dimensions aren't "normal'. 4k is typically 4096 x 2304 (16:9) or x 2408 (2:1). I've never seen x 2160 before, and trying to keep that same oddball aspect is what's causing the previews to go to weird dimensions, which is what's causing the distortion and black line.
Hi again Jim, 4096 x 2160 is the full frame of the Scarlet images that we shot. I plan to go to 2:35 in the end, but though I'd edit with what was shot. Any thoughts on codec to change for my previews?
Import the video and drop it on the "New Item" button to create a sequence that matches the source. Anything else is probably asking for trouble.
Then, I suggest you merely change the 1919 to 1896. That should make your second number divisible by 8 also - I hope. My best guess is that you might be able to get 1896X1000. Both 1896 and 1000 are evenly divisible by 8. (Jim is correct about that, of course. The whole thing falls apart if both numbers are not evenly divisible by 8.)
See if that changes things.
Now, I found something interesting. I downloaded a couple of RED clips. One was 4096X2304 and the other was 4480X1920. The first one produced sequence settings with preview files of 1920X1080. I like that just fine. The second one gave me 1918X822. Interesting. And I guess we know what your 4096 x 2160 does.
I looked for black lines after rendering the one with previews of 1918X822. I couldn't spot them. So I can't check to see what happens if you change it to 1896. Please give it a try and let us know if that helps.
Any thoughts on codec to change for my previews?
Well, give Steven's advice a go first.
And keep in mind, previews aren't always necessary to the edit process. You should only create them when you have to see realtime preview and dropping the playback resolution just doesn't cut it. Further, you should not be using those previews for export anyway, so creating them when you don't need them will only slow things down.
Europe, Middle East and Africa