On Nov 21, 2013, at 8:54 AM, Ashley Retallack wrote:

I was wondering what the best practice is to get an acurat result from nuke as far as compositing a vd16 image with an alpha from photoshop with a linear space. As the result always come out very different to what I have in photoshop. The only way to get a result that is the same is by merging in vd16 space and the converting back to linear afterwards.

Is there a safe way to convert a vd16 image with alpha to linear and have it combine with a similar result as combing two vd16 images.

You will get different results when comping in linear vs. video spaces. It's an order of operations thing and really can't be helped. Easiest thing is to comp the layers in video space and then convert the result to linear. If you're inserting an element in between, you might want to convert it to video space.

The standard Over operation with fully opaque pixels should work the same in either case, but when you have transparency or other modes like Add, you will see changes. If you must comp those layers in linear, you can make color corrections and other adjustments to try to compensate for the differences you're seeing, but you won't be able to get it to match exactly.


Brendan