Reducing data: increasing compression vs decreasing resolution

[Jordan Beard]

I'm prepping for an upcoming shoot involving several lengthy interviews and I'm curious what the best practices are for shooting while reducing the amount of data produced. Should I shoot 5k with higher compression ratio (~9:1) or 4k with a lower compression ratio? I've done a few tests but I'd love to hear other opinions. Any advice or links to relevant threads would be greatly appreciated!

 

[Anton Shavlik]

Resolution increases visual quality faster than compression loses it. If I was looking for a certain data rate I'd always take the highest resolution I could.

5k 9:1 is not bad at all, especially in an interview where the background is likely soft and out of focus, and lighting can make sure noise is at a minimum.

 

[Michael Tiemann]

My experience is that resolution beats compression as long as both are in the linear zone. But when compression "breaks", which is sooner in some cases and later in others, it breaks bad. The only way to know what you are up against is to test your compression level and see if it breaks. As others have said, if you use the Edge Detect look you can get an idea of how much complexity the compression has to worry about. If the image has tons of fine detail, best to keep compression to a minimum and back off on resolution.

And another thing: because of the superior noise characteristics of DSMC2 DRAGON vs. EPIC DRAGON, you can still get a better image from DSMC2 at REDCODE X+1 than EPIC DRAGON at X, and you can get almost equivalent results at REDCODE X+2 on DSMC2 vs. REDCODE X on EPIC DRAGON.

 

[Michael Lindsay]

Resolution increases visual quality faster than compression loses it. If I was looking for a certain data rate I'd always take the highest resolution I could.

5k 9:1 is not bad at all, especially in an interview where the background is likely soft and out of focus, and lighting can make sure noise is at a minimum.

Different photographic approaches will make a difference.

We have tested this in detail and found it not to be the case for many scene types (not interviews)

Little to no motion blur, deepfocus, sharplenses, and a scene with lots of high contrast detail will mess you up unless you get the compression right down.. that said, and as you mention, an interview would probably be fine.

If the Revanant had been shot Red I would have recommended 3 to 1 ;-)

Ps my tests where Dragon not helium

 

[Björn Benckert]

My wote goes to keeping resolution high and increase the compression. Then if you got weapon you also have prores....

 

[Harvey Burrell]

Red tether for sure.

 

[Marcus Friedlander]

This thread should be required reading for all redusers.

http://www.reduser.net/forum/showthread.php?124071-Compression-Wedges