Okay, I have some more information. I asked someone who had mentioned it, and they gave me this page from John Knoll's book Creating the Worlds of Star Wars: 365 Days (2005): Spoiler So we can see that they added this Pro-Mist lens filter to soften the image that had too much perceived sharpness. I looked up before/after comparisons for Pro-Mist lens filters and saw that they diffused the light, which explains that hazy look that AOTC and ROTS sometimes had. However, I didn't actually see any extra noise added by them. But I did find this post by a cinematographer in 2005 who said So even though modern Pro-Mist filters don't seem to add any noise (as far as I can tell, but professionals who have a better eye for this may feel differently), they did seem to add some kind of noise to the image back in 2005. So while this isn't the same as a "grain plate" that I had previously thought, it may explain the noise we are seeing in the film.