Sorry I misinterpreted your post. Also, there are many other readers on here who are not nearly as well seasoned in screen technology as you are after your 22 years on the forum, so I also post for their benifit too. There are a few screens out there that exhibit true lambertian diffusion.Hi Don,
Thanks for the further explanation of Fresnel/UST issues, but that wasn't the point my comment.
You said "for UST projectors, a high quality Lambertian white or Lambertian neutral density gray screen surface will give the most pleasing and most uniform image, (no hot-spotting) in light controlled rooms."
I interpret that to mean that for the best pic w/UST, forget Fresnel screens and use a Lambertian screen, which must therefore actually exist.
Again, I didn't think that there were screens that actually approached Lambertian behavior closely enough to work at such extreme angles.