EX1 users: Vegas 8bit changes footage look

essami wrote on 4/6/2008, 11:32 AM

Hi,

I just had a revelation after trying to for a long time get good images out of my EX1 footage. My problem that I did not realise turns out to be that using 8bit timeline with no color space conversion changes the images. This has been said by many people in the past but I thought it good to to re-cap.

Sony Clip browser: Image OK
Vegas explorer (no matter if project is 8 or 32bit): Image looks washed out
Vegas timeline 8bit: Image looks washed out
Vegas 8bit with Studio to Computer RGB: Image OK
Vegas timeline 32bit: Image OK

thanks to Randy, Glenn and everyone at dvinfo for helping me figure this out. Im finally getting good results.

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Comments

farss wrote on 4/7/2008, 2:54 PM

"Looks better" is a very subjective statement. Why not record some bars in camera and then process through both pipelines and bring the results back into Vegas and compare them on the scopes. Only need a few seconds worth to do a test like that.

What has me confussed is in the scenario you're describing is you're almost if not actually smart rendering.

Bob.

GlennChan wrote on 4/8/2008, 12:05 AM

For Cineform users, the Cineform converted .avi files are in Studio RGB and with an 8 bit project rendering to Main Concepts nothing need be done. If such a project is set to 32 bit BEFORE CC then the whole track, using Track FX, need have a Studio to Computer conversion done also BEFORE CC AND ALSO a track FX levels adjustment so the histograms, when properly set for the color space, LOOK THE SAME in the 32 bit project as they did in the 8bit.
Right.

I'd avoid the trackFX level however, since there can be some weirdness if you fade to black. Apply those levels conversions at the eventFX level (you can also do it at the mediaFX level, but that will be slower if you do pan/crop and make the image smaller).

If the codec you're rendering to wants to see the other levels (computer or studio), then you'd apply a studio<-->computer RGB conversion on top of what you've already done. I'd recommend you nest your .veg into a new .veg and apply the conversion there (at any of the FX levels). The other way of doing things, applying a Levels FX at Video Preview (or track), can be dangerous if you forget to take that FX out (e.g. render to new track).

GlennChan wrote on 4/8/2008, 12:08 AM

A compositing gamma of 1.000 would explain a difference. What compositing gamma are you using?

2- It's also possible that there are differences in the codec between 8-bit and 32-bit mode... there might be really (really) subtle differences in rounding error.