Re: vd16 and alpha channels PS -> Nuke

Ashley Retallack <ashl...@...>


Thanks for the reply. Yes that's what I thought. so it's more that comp and reprojections need to over in the space space as the matte painting was done in rather than trying to correct the alpha to work with the converted color.



On 21 November 2013 17:27, Brendan Bolles <bre...@...> wrote:
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.


You received this message because you are subscribed to the Google Groups "OpenColorIO Developers" group.
To unsubscribe from this group and stop receiving emails from it, send an email to ocio-dev+u...@....
For more options, visit

Ashley Retallack | Pipeline Engineer 

BlueBolt Ltd | 15-16 Margaret Street | London W1W 8RW | T: +44 (0)20 7637 5575 | F: +44 (0)20 7637 3296 | |

Join { to automatically receive all group messages.