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EXR format worths?

Posted: Wed Sep 21, 2011 6:51 am
by areyal
Hi,

I was wondering if exr format has such advantages (compared to png 48 bit, for example)
Yes, I find it better when I have to tone the image, but I can do almost the same with png
EXR is not so extended and I'm afraid about compatibility issues

Regards

Re: EXR format worths?

Posted: Wed Sep 21, 2011 8:42 am
by Refracty
exr as well as pngs are both standard formats in compositing so don't be afraid of compatibility.
Usually 16 bit per channel is quite enough (png) for post tweaking and it will save disk space compared to 32 bit (per channel) exr.
But exr has other advantages. It can hold many different channels in one file (like specular, shadow passes ect.)

Re: EXR format worths?

Posted: Wed Sep 21, 2011 9:16 am
by areyal
so if I understand the main advantage of EXR are the aditional channels?

well, then I'll continue with PNG because additional channels (specular or reflexions) can have advantages in biased renderers, but in an unbiased as Octane I doubt it could for example separate reflexions or caustics in channels. Or am I wrong and Octane can do that?

Thanks for the reply

Re: EXR format worths?

Posted: Wed Sep 21, 2011 11:51 am
by matej
areyal wrote:separate reflexions or caustics in channels. Or am I wrong and Octane can do that?
No it cannot.

Re: EXR format worths?

Posted: Thu Sep 22, 2011 7:15 am
by areyal
After some test, I've found the "tone mapped" EXR interesting. Is the first time I use this format.

It seems washed, but when you adjust the levels in Photoshop you have a wide margin to retouch

Can some one post oppinions/advices?

Regards

Re: EXR format worths?

Posted: Thu Sep 22, 2011 9:41 am
by Refracty
This is related to linar workflow.
You have to correct the Gamma Correction in Photoshop by the factor 0,454 because this is 1 divided by the standart Gamma of 2,2.

1/2,2 = 4,454

Then you have it right.

Re: EXR format worths?

Posted: Thu Sep 22, 2011 6:51 pm
by areyal
Ok, thanks