I'm not sure how to get exposure consistent. There seems to be a change between the texture and the 3D viewport (even with unlit shaders). It drops by about half in brightness from the PNG. Then when I get the preview, even without a post effect it seems to drop again by half in brightness. Is there a general pipeline for 3D objects that I need to be aware of that maintains brightness all the way to the snap?
I tried to replicate your problem but everything seems to be fine as you can see in the picture below:
What version of Lens Studio are you using? Did you upgrade your project from one version to another version?
Please download the latest version of the Lens Studio and create e fresh new project and see if you still have the same problem.
If you still have the same problem, please share some screen shots and also project files.
Looks like I just needed to start with a fresh project. I did notice that part of it was the "Base Color" is multiplied by the Diffuse Texture. I wouldn't call that my most desirable default behavior either.