I have heard a lot of good things about both the JKP screens as well as the Stewart Neve and Snomatte in this forum. Alas, I don't have screen samples of all of them, but I have the JKP screens, the Studiotek 130, and then I threw in the Carada BW and CW for good measure. I particularly focused on transparancy and brightness as those are my main concerns. Though I feel the small sizes of the samples make the former a bit difficult to evaluate. After all the HP also looked quite transparant when looking at a small sample, but much less so when panning a whole screen.
These are my subjective opinions:
The Carada screens had very smooth surfaces and didn't show any screen texture or visible artifacts that I noticed. However, they were also clearly dimmer then the higher gain JKP and Stewart screens.
The Studiotek was brightness wise quite similar to the JKP 1.3 screen. The JKP a little brighter right in the sweetspot, wheras the Studiotek was brighter when moving slightly outside if it and clearly so when moving far to the side. (though this was in a direct A/B comparison and I dont believe I would have picked up on it if viewed on their own). Both screens had perfectly smooth surfaces, but where the studiotek had tiny shiny sparkles that were visible when studied up close, the JKP 1.3 completely lacked any visible sheen. With normal light that is... When viewied under projected light and standing close to the sample but in the sweetspot, I could see a very obvious shimmering, diffracting pattern that moved around as I moved my head around. At first I didn't notice it from the sofa, but after seeing it up close and knowing what to look for I could still spot it 4 m away (depth of the room). I first thought it could be some kind of moire, but it persisted when I zoomed the image size in and out. I don't know if it could have something to do with the polarization of the projected light as this phenomenon is completely absent in normal light? Perhaps it won't show on DLP's or LCOS projectors with the RGB polarizers aligned in different directions (e.g. Sony?) as I haven't heard of it before. Anyways, this completely ruled at the JKP 1.3 for me. When looking at the JKP 1.1 and 0.9, they displayed the exact same effect, though to a lesser extent. Still slightly visable from the seating position when moving my head. (and I fear it will get worse with a full size screen).
Thus it seems the Studiotek would be my best option. However, I still feel a bit trepidition for the sparkles. Though the screen sample was completely transparent from the sofa, I think it might be something else with a full screen. The option then seems to be the Neve or Snomatte materials. However, I haven't seen neither and I don't think there is any place to demo them closeby. Perhaps my best bet is to order screen samples from stewart? Also, I'm not so sure how much is the projector and how much is the screen? I can actually see the screen door effect from my seating position 3.5 meters away. Maybe this is contributing to the artifact seen in panning motions? What do you say guys, can a bright panning scene be completely transparant with regards to solid or moving patterns on the screen? If you have a JVC and a good screen maybe you can test it without eshift and see if you can spot anything?
Othwerwise, any thoughts?
Also, I took some (crappy) pics with my phone showing the relative brightness of the samples through my 3D glasses worn straight or tilted 90 degrees to show how much polarization they retain (big difference in brightness means high degree of polarization is preserved by the material). Also included is the Firehawk G3.
The samples are on a white wall and as follows: Carada BW, JKP 1.3, Studiotek G3, Carada CW, Firehawk G3.