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mash 05-15-2008 04:19 PM

Using EXR elements
 
Hi, I'm working on a couple of matte paintings at the moment using 3d elements. The 3d department and comp wants to keep everything in linear color space so they are rendering the CG elements as EXR files.
I was wondering if anyone else has had this problem and how did you go about dealing with it?
Also how do you deal with previewing your images for film output?
Do you use a LUT in photo shop or go though a Comp program and look at it there?
thanks,
Mike

rrische 05-20-2008 11:08 PM

Hi Mash,
What specific problems are you having?

I'm currently working on a film where we are doing many 3D projection shots.
Here's how the workflow is happening....

3D renders a still from the projection camera(s) for the matte painters.
These files are 32 bit EXR's. We open them in photoshop and convert them
to 16 bit. Paint paint paint. Finally, we convert them back to 32 bit EXR's
for reprojection and compositing.

BUT, I learned something quite valuable. If you are converting from 16 bit
to 32 bit, you will have problems with your layer transparency, especially
if you have layers set to anything less than 100% opacity. Changing to
32 bit will change the appearance of your layers unless-

You go to the edit menu. Choose 'edit>color settings'
When the dialogue box comes up, choose 'more options'
The last checkbox on the bottom should be 'Blend RGB Colors using Gamma 1.0".
Check this box.

Now, when you convert your layered Photoshop file to 32 bit, the appearance of your layers will stay the way you want.

In order to save your file with layers intact (handy for sending separate
cloud layers to another program, for example) you will need a 3rd party
plugin, as Adobe's implementation of OpenEXR is very basic. The only
plugin I know of that will open and save layered EXR files is 'ProEXR'.
I have it and it works.

Good luck.

GordonTarpley 07-25-2008 09:26 AM

wow!

"...You go to the edit menu. Choose 'edit>color settings'
When the dialogue box comes up, choose 'more options'
The last checkbox on the bottom should be 'Blend RGB Colors using Gamma 1.0".
Check this box..."

i feel like i just stumbled across a bar of gold!
thanks!

Gossioii7 04-17-2009 01:53 PM

useful tips
 
This is great! It really shows me where to expand my blog. I think that sometime in the future I might try to write a book to go along with my blog, but we will see…Good post with useful tips and ideas


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