Hey hey, i heard this one before i gues. I went to google it and i fond in creative cow a thread what i think is the issue you see . I copy paste it here maybe it is of help for youre issue :
2944×2160 is a ProRes format with black padding left/right, the active image is actually 2880×2160.
Currently there are two way depending on your lens choice:
a) 4:3 2.8K with anamorphic lenses
– set your project resolution to 2048×858
– set Input scaling preset to “Scale full frame with crop”
Since the 4:3 is way too wide for 2.39 we need to do two things: crop & scale.
for the 4:3 2.8K shot set sizing “Zoom” to 1.142 (2944/2578) and “Height” to 0.5 to squeeze the image.
Now you can edit your 2048×858 next to this shots.
from:
https://forums.creativecow.net/docs/forums/post.php?forumid=3&postid=999640&univpostid=999640&pview=t
Aspect Ratio = (Horizontal Resolution / Vertical Resolution) × Pixel Aspect Ratio
https://forums.creativecow.net/thread/3/1005181#1005187
ts a big reduction in quality. you can upload 4k to youtube as youtube will automatically letterbox.
as you have surmised, going from anamorphic to 16:9 won’t be pretty.
Since:
Aspect Ratio = (Horizontal Resolution / Vertical Resolution) × Pixel Aspect Ratio
so your AR = 2.66666 square
and 16:9 = 1.77 square
To fit the player perfectly, encode at these resolutions:
2160p: 3840×2160
1440p: 2560×1440
1080p: 1920×1080
but if you had to keep AR, 2.6 square would be 1920/720 square pixels or 2880×1080.
anamorphic videos will be letterboxed in both 16:9 and 4:3 players. The player can only do this if the native aspect ratio of the video is maintained – i.e. don’t add black bars to the video itself.
Note: If you add letterboxing to a video before uploading it, the widescreen player will add vertical bars, resulting in black bars all around the video and a bad viewing experience.
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