Why do Proxy File sizes vary with Resolution ?

[Paul33]

Is there a simple explanation as to why VS proxy files for 4K clips are smaller than the same duration clips shot at 1080HD ? I would have expected the proxy files to be identical and in line with preferences no matter what resolution the source file was.

Not an issue, just can't explain it !!!

[Ken Berry]

I'm exactly sure what you are saying. What settings are there for the proxy files? As you are probably aware, proxy files are copies of the original but in a far lesser format than the originals, and a format which is easy to edit and relatively quick to play back. So the proxy files will always be considerably smaller than the originals. Sometimes for 4K the proxies can be 1080p, and this is possibly where your comment comes from. But if, as I imagine, the bitrate for the 1080 proxies is quite low e.g. 5000 kbps or even lower, again the size of the those proxy files would be much lower than full HD video files at, say, 16,000 or 20,000 or even higher kbps. For any format of video, the higher the bitrate, the larger the file will be...

Or did you mean something totally different...?

[lata]

Hi
Not noticed this myself, If you compare the Proxy files created for two video files, same duration.
The 4K version I would expect to be larger than the HD version, but not so the 4K proxy file is smaller, considerably smaller
These were 30 second clips

click image for larger view

[Paul33]

Not sure I know what I mean LOL !!!

I have two ten second clips from different shoots and they are ......

Clip 1

Resolution: 2048x1152
FPS: 25 fps
Bitrate: 33 Mb/s
File Size: 41.2 Mb
Proxy File Size: 27.8 Mb

Clip 2

Resolution: 3840x2160
FPS: 30 fps
Bitrate: 84 Mb/s
File Size: 104.2 Mb
Proxy File Size: 19.9 Mb

Just puzzled as to why the proxy file for Clip 2 is smaller than the proxy file for Clip 1.

The reference to "preferences" was because I thought the proxy settings set the dimensions for proxy files. Is that not the case ?