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Resolution vs compression
1683 2 2018-12-1
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Sharky1
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I read here and elsewhere people where picking lower resolutions to yield less compressed video for better post color grading.  I went out and did some test files  recorded at C4K, 4K and 2.7K.   I checked my file size vs length in time combined with this calculator https://toolstud.io/data/filesize.php?speed=60&speed_unit=Mbps&duration=5.5&duration_unit=minutes&compare=harddisk. Checking vs 60 mbps and I believe I verified C4K and UHD 4K at 24fps each are at 60 mbps as close as I can tell.  2.7k is right about 45 mbps that I have read elsewhere.   Since C4K and UHD same frame rate, same 60 mbps but different sized image the C4K should be more compressed per frame or pixel.   So I multiplied the dimensions of the frame divided by the mbps and yielded a number.   I’m not really sure what that tells me, but I ended up with C4K 147,4565.  UHD 4K 138,240 and 2.7K at 92,551.   Again not sure what that is telling me, but I thought I would share the math.  I assume the lower the number is less compression or ratio since C4K and UHD 4K I’m 99% sure came out to the same 60mbps so it only makes sense the lower resolution image would have less chroma or other data dropped.   Maybe someone who knows more would chime in.   Anyway I’ll have to go out and try to grade these 3 sample rates (same time and place) and see how much I can push any of them or grade them for ease.  I have heard numerous times that the 2.7K is easier to grade quickly in post and hardly descernable differnt sharpness.  Thoughts?
2018-12-1
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Sharky1
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United States
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Double post
2018-12-1
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Sharky1
lvl.1
United States
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Wrong math.  H x W x fps = pixels per second.  Then mbps / pps = bpp. A quantifiable relation.  http://community.ooyala.com/t5/D ...
2018-12-1
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