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Exposure blown out in final file but not in Picture Viewer

Posted: Sun Oct 20, 2019 4:36 pm
by shane_rhodes
I'm having an issue with the final output of my render. Everything looks great in the Live Viewer and the Picture Viewer but once I open the .tiff or PSD, the image is incredibly blown out. It's not something I can fix in the image editing software as the blown out pixels are actually blown out to the point of lost pixel data. I've never had this issue before but now it seems to happening with every render. What am I missing?
Image from the Picture Viewer (how it should look)
Image from the Picture Viewer (how it should look)
What the image looks like in Photoshop (or any image viewer)
What the image looks like in Photoshop (or any image viewer)
Octane Settings
Octane Settings
Render Settings
Render Settings

Re: Exposure blown out in final file but not in Picture Viewer

Posted: Thu Feb 17, 2022 6:04 pm
by RyanScammell
I've been having a similar issue lately as well. It seems pretty intermittent and it's been very difficult for me to nail down what change seems to be causing the issue in a given file. I will also say that I was talking to another motion designer today who said he's having the exact same issues. Both of us have sometimes found copying all our elements into a new project seems to solve it but it doesn't help me understand what I could have accidentally changed to cause the issue to arise. To put into perspective, I'm pretty consistently using the same settings on all my projects so it's unclear what would be different in starting a new file. And more importantly why the live viewer would show something correctly that then would render incorrectly.

FYI on all my machines I'm running 2020.2.5 because I was having some issues with 2021 and downgraded back.

Re: Exposure blown out in final file but not in Picture Viewer

Posted: Thu Feb 17, 2022 7:25 pm
by aoktar
You should use same color space when you import images. Otherwise it will be different than LV or PV.

Re: Exposure blown out in final file but not in Picture Viewer

Posted: Thu Feb 17, 2022 8:54 pm
by RyanScammell
I'm not sure what exactly you're referring to. Whenever I import an image texture or an HDRI I don't change any color space settings. (Not in the project or in the image texture node itself). Is it something specific to the file being imported?

Re: Exposure blown out in final file but not in Picture Viewer

Posted: Thu Feb 17, 2022 9:03 pm
by aoktar
RyanScammell wrote:I'm not sure what exactly you're referring to. Whenever I import an image texture or an HDRI I don't change any color space settings. (Not in the project or in the image texture node itself). Is it something specific to the file being imported?
It's clear enough. You should use a similar color space in pshop what you're using to view in plugin's interfaces. I'm not using pshop btw.

Re: Exposure blown out in final file but not in Picture Viewer

Posted: Thu Feb 17, 2022 10:12 pm
by RyanScammell
I can't speak to Shane's situation but look at this on my end:

This is Twister D v4 straight out of octane.
Twister D v4_0142.png
This is Twister D v6 straight out of octane.
Twister D v6_0027.png
On my end those look very different regardless of whether they're in photoshop or after effects or preview or whatever.

And to clarify, both files have octane settings set to SRGB (and the C4D project settings are also both set to SRGB & Linear Workflow).

Here's a link to both files if it's helpful:
https://www.dropbox.com/s/pvocgtl9s6gzl ... 4.c4d?dl=0
https://www.dropbox.com/s/pa3nl7762c1oa ... 6.c4d?dl=0

And to further complicate things here's the same project rendered out of my laptop instead of my desktop. Same exact project but different result.
Twister D v6_0000.png

Re: Exposure blown out in final file but not in Picture Viewer

Posted: Thu Feb 17, 2022 11:28 pm
by aoktar
This is not a case I can help you, because it's not a plugin related issue. Better to talk with support team for learning how to set your color management pipeline.

Re: Exposure blown out in final file but not in Picture Viewer

Posted: Fri Feb 18, 2022 2:53 pm
by RyanScammell
I'm not sure how you can say for sure it's not a plug-in issue. We're talking the same file produces different images just by rendering the exact same file on a different computer. It's clearly not as you initially suggested that the problem is in the Photoshop settings, because as you can see these are just PNGs straight out of octane and uploaded directly to this site. So I'm not quite sure where the "pipeline" is that you're referring to. The file comes out of octane one way on one computer, and a different way on a different computer with all the same settings. Then it gets posted straight to this forum. So there's no real pipeline here. It came straight out of octane and then got posted here.

This is an issue that's only popped up somewhat recently (within the last 4 months) so maybe it's something that's related to R25? Or a new Nvidia driver? I'd just be hesitant to so quickly dismiss it as not related at least in some ways to the plug in.

Re: Exposure blown out in final file but not in Picture Viewer

Posted: Fri Feb 18, 2022 3:12 pm
by elsksa
Hi,

I see that the Exposure was set to "2.2", unless it is a coincidence, the γ2.2 value is usually referring to the approximation of the piece-wise function (sRGB EOTF). Octane's color-management is covered on my article: https://www.elsksa.me/scientia/cgi-offl ... management

PSD export is nowhere a standard in productions/studios.
I would advise to favor OpenEXR and an appropriate software for post-work, other than PS, such as Nuke, Fusion or equivalent (including Blender Compositor).
More information about file format - not all of them are covered as the article is focused on the highlights of OpenEXR: https://www.elsksa.me/scientia/cgi-offl ... mat-debunk.

Last but not least, the wording of "exposure is blown out" is fallacious. What is referred as blown-out are the values contained in the exported light-data of Octane rendered scene. A scene can be over-exposed without being blown-out. The nuance between the two is capital.

I could also suggest a more generic informative article: https://www.elsksa.me/scientia/cgi-offl ... rvival-kit.

Octane, as far as I know, does not contain any obvious "color-management related" bug. Most of them are user-errors from uninstructed/unaware users.

Re: Exposure blown out in final file but not in Picture Viewer

Posted: Fri Feb 18, 2022 7:09 pm
by aoktar
Hello @Ryanscammel,
I'm saying because I know what we did as a developer. You are asking something not our mistake or something needs to be fixed. Any devs has not to spend their work time on finding and fixing user mistakes. We have support team for helping you if you cannot find and learn the usages. I'm answering some posts if it's quick to help. I'm being away if something is time consuming. Hope it's clear, regards!