Linear workflow question

[prodviz]

Could be that you need to add an exposure node in photoshop and adjust gamma to 0.454.

(Or if it's the maya scene of the bottle we were looking at, I think I accidentally added a 2.2 to the camera's gamma, when it should be gamma 1 - when using a response curve, sorry).

[itsallgoode9]

Just talking about in general, and yeah i've been adding exposure node in PS. This is the correct way to do this and not just a bandaid?

[prodviz]

Cool.

I'm not sure if this is the right way or just a bandaid type deal.

8 bit jpegs have a burnt in Gamma of 2.2, and .exr's don't (correct me if I'm wrong there).
I wonder if Photopshop is adding a Gamma to the display of a 32bit image, so that's why they're washed out and we have to add (reverse 2.2) exposure node?

[DartFrog]

If your camera gamma is set to 2.2, and your response curves are set to linear (in the actual camera object) and you are saving your HDRI file with a forced 1.0 gamma (this should be default for hdri) and "standard RGB channel" if given the option, then no, you stuff shouldn't really be washed out. If it's washed out, consider your lighting setup. Maybe there's just too much light. If you're not sure, post a pic here and we could probably tell if it's more washed out than it should be. If it looks good in your preview and looks good while rendering, but saves washed out - it's a saving issue and something needs to change in your settings when you're saving. Changing gamma to .454 or whatever is a band-aid, to me.

[itsallgoode9]

thanks ishook. i thought that was maybe the case. just that I wasn't used to working with the way a lighitng curve works in a linear workflow and I needed to adjust my approach to lighting. I'll do some more testing when I have time and see how it goes. thanks for the feedback

[itsallgoode9]

So here's a render I did that shows off, what I think, my issue is. btw, i'm working in maya plugin

The render is getting too much light in some weird places. that shadow behind the can is washed out overall. The lighting hitting the can itself seems as if it's wrapping too far around the can. There is nothing else in the scene besides the single light (and that sweep is pretty far back) so it seems like it shouldn't be nearly this bright in the shadows. The material on the base of the can is the same material as on the top but it is much lighter. Sampling colors from the render, nothing in the entire render goes fully white, so I don't think any of this is an issue of my lighting being too bright (this image actually looks underexposed to me). The Value of the diffuse for the glossy material applied to the can is .400 but it is render much bright than that.

it's just a whole laundry list of stuff. As far as I can tell, i'm following methodology exactly but I must be missing something still. thoughts?



Here's the non linear verion (camera profile in the imager, 1.0 gamma, color management off)

[prodviz]

Are the issues with the first shot down to the default settings in Maya having a Agfa response curve?

Does setting the Gamma to 1 (as you've got on the second image) and then changing the Image Color Profile to Linear sRGB (in the render window settings - as Ciboulot mentioned in a previous post) give you the correct result?

[itsallgoode9]

Are the issues with the first shot down to the default settings in Maya having a Agfa response curve?

Does setting the Gamma to 1 (as you've got on the second image) and then changing the Image Color Profile to Linear sRGB (in the render window settings - as Ciboulot mentioned in a previous post) give you the correct result?

first image is setup with everything setup the way I understand linear should be. Camera response curve off. color management in render globals set to srgb input, linear output gamma set to 2.2, color profile input in render window set to linear, device output set to sRGB.

2nd image is using agfa response curve, gamma set to 1, color managment in render globals turned off, color profile in render window have both input and device set to srgb.

So basically, prodviz, your first sentence is the setup i'm using in the 2nd render. and your 2nd paragraph is my setup for the first render. If i raise the lighting in the 2nd render to the correct brightness (the image posted is pretty underexposed) it looks pretty nice.