Gamma of material preview doesn't match final render

[fooprobe]

Thanks for the very clear response. I would love to use the simplest possible methods, but I find that it is very common to see the difference as shown in the example I posted. I teach a class of about 10-15 students three times a year, plus other classes and this issue is extremely common, both with backgrounds and textures. We don't do a lot of product renders so I can't comment on that.

So we will continue to turn off linear workflow and turn on RGB and LDR correction. We always use these settings and never see any issues.

thanks!

[mikel.jagan]

Hey,

One really important that we over-looked that seems to be the issues here is that we noticed you are using a .jpeg for your background -- this is what is causing such a dramatic shift. If a 32-bit .exr or .hdri is used, the issues that we have been discussing do not occur and keeping the "Linear workflow" box checked would work in your best interest.

[fooprobe]

Yes of course, and it's great that there's a workflow for those who will take the time to use HDR input and output.

But most images for textures and backgrounds are coming from Google and will be jpegs. Guys, the images you use in your own materials library for download from this very site are 8 bit, not HDR. Openfootage is the only source I'm even aware of for 8k+ HDR panos, and their stuff isn't free. And it takes longer to render. HDR in/out is simply not the easiest workflow, and it boggles my mind that it's the default. But hey, at least there's an LDR workflow, and it's not that hard to set up, that's all a poor boy can ask for.

[mikel.jagan]

Hey there,

I understand. There are some free HDRI's out there, and making your own can be a bit time consuming, but the results are really nice. Also wanted to clarify; images for material textures do not need to be 32-bit, 8-bit is fine. As far as environments and illumination on dome lights, backgrounds and skylights -- these should ideally be 32-bit .exr or .hdri files, emphasis on ideally. While you can use 8-bit files in the environment channels, be aware that there will be issues as there's simply not enough data to illuminate a scene. :/

[renee81]

I love so much the light you get with hdri /lightdome that I don't use the sun anymore.
Like Mikel said,some free ones can be find,personnaly I love the ones from Peter Guthrie,while they are not free,they are not that expensive,and for some project it is worthwhile,and you can use them over and over,so to me it is a good option.

[fooprobe]

We always use HDRI for skylight - I agree 8 bit is usually pretty useless for that. But those images can be low res and are readily available in great variety, especially for exteriors (which is where it matters most for arch vis). It's the backgrounds that are an issue. And HDRLabs, CGSkies, etc typically provide files in that prescription: low res HDR, hi res 8 bit.

I'm pretty sure we've had problems with 8 bit textures using linear workflow, but maybe I'm misremembering. I'll post one if I can find one.

thanks for the help.