Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: jjduncs on 2016-10-31, 12:20:36

Title: Corona 1.5 LUT vs ArionFX LUT's
Post by: jjduncs on 2016-10-31, 12:20:36
The amanmq built in LUTs share the same camera models as many of the ArionFX LUT's, yet they seem to output very different results.  Should the LUTs applied in frame buffer and in PS/Arion on a 32bit EXR be the same/very similar?

I have attached two images below, one with LUT applied in Corona, the other in PS with arion. Both using the a 'Canon DSC 315 #5' LUT
Title: Re: Corona 1.5 LUT vs ArionFX LUT's
Post by: Tetsuoo on 2016-10-31, 14:23:29
I love ArionFX I really can't do without it now, I use it for photos as well even if it's not 32 but 12 bits, it still worth it.

I can't tell for Corona but it looks like there's a gamma correction problem here. It's easy to be lost in all those settings, even more now with 1.5 -_-
Title: Re: Corona 1.5 LUT vs ArionFX LUT's
Post by: maru on 2016-10-31, 14:44:50
I guess this could be this: https://forum.corona-renderer.com/index.php/topic,13515.msg87161.html#msg87161
Or maybe in Corona something else is affecting the LUT, since other post processing operations are considered.
Could you send a more extreme example? Maybe with some hardcore instagram looking LUT?

I can't tell for Corona but it looks like there's a gamma correction problem here. It's easy to be lost in all those settings, even more now with 1.5 -_-
What settings do you mean specifically? In Corona you shouldn't touch virtually any settings, and if you do, they should not be confusing. An explanation would be greatly appreciated!
Title: Re: Corona 1.5 LUT vs ArionFX LUT's
Post by: jjduncs on 2016-10-31, 14:55:13
I thought it may have been a gamma issue. The LUT seems to flatten the image when applied in the VFB, but tends to add contrast when applied in arion. Will upload more dramatic LUT soon.
Title: Re: Corona 1.5 LUT vs ArionFX LUT's
Post by: jjduncs on 2016-10-31, 15:04:47
For this test i reset all corona processing to default (HC and contract back to 1.0 etc).

Still appears some gamma issue is happening with the in built corona LUTs.
Title: Re: Corona 1.5 LUT vs ArionFX LUT's
Post by: TomG on 2016-10-31, 15:10:17
BTW, just to check my understanding - in one image, you use a LUT provided with Corona with a particular camera name, applied in the VFB; then in the other you use a LUT provided with Arion that has the same camera name, applied in Arion? So each image uses a different LUT file (albeit with the same camera / film stock name), as well as the different software? If that's the case, what happens when you load the Corona LUT into Arion and use it there, and / or load the Arion LUT into Corona and use it there? Just to narrow down variables :)
Title: Re: Corona 1.5 LUT vs ArionFX LUT's
Post by: jjduncs on 2016-10-31, 15:14:35
I will try that now.

Tho I was assuming adanmq's LUT's would be the same (or at least very close) as ArionFX's given the camera list is identical and so are all the specific camera names. It seems they do respond very similarly except for the gamma(?) difference, with all the in built LUTs being a slightly flatter image.
Title: Re: Corona 1.5 LUT vs ArionFX LUT's
Post by: jjduncs on 2016-10-31, 15:19:38
Applying the Corona LUT file through Photoshop Colour Lookup matches the ArionFX LUT.

It is when it is applied through the VFB that the issue is happening.
Title: Re: Corona 1.5 LUT vs ArionFX LUT's
Post by: TomG on 2016-10-31, 15:37:49
TY for the extra testing and info! It rules out any difference in the LUT files.
Title: Re: Corona 1.5 LUT vs ArionFX LUT's
Post by: Fluss on 2016-10-31, 21:22:44
Some LUTs are meant to be used in a log color space. If i remember, there is a checkbox for that in render settings. Did you tried that ?
Title: Re: Corona 1.5 LUT vs ArionFX LUT's
Post by: jjduncs on 2016-11-01, 01:29:49
Yes have tested that in PS and Corona. It's not it unfortunately.