Originally Posted by johnkol
I looked into higher gain screens, but from what I have read they require a long-throw lens to avoid getting hot spots; I believe the rule of thumb was to use a throw ratio of 1.5 or higher. If someone could still make a retro-reflective screen with 2.4 gain...
That's not really accurate.
A screen with a reflective coating for increased gain can potentially have artifacts, however there is a differentiation between ALR screens which are usually grey and white screens with a slight gain increase.
A grey screen may have a 0.5 base for example. To reach 1.0 or 1.5 even the optical coating needs to raise gain by 0.5 or 1.0 gain.
A screen with a white base already is 1.0 and to reach 1.1 or 1.3 only 0.1 or 0.3 is required.
This makes the white screen much less susceptible to any artifacts. The 1.5x or 1.8 recommendations are for ALR type fabrics, not for what is essentially a white screen.
The quality of the fabric, technology used is also relevant. As it's mentioned above, the SI Solar White even though it's white and only has a 1.3 gain still has some sparkle. The poster did not mention the projector used or the throw range, which are important elements. Some posters have noticed even regular 1.1 white screens sold by Elite and ST can hotspot at ~1.4x throw ratios.
It's unclear what the effect will be with a throw of 1.13x with a projector like the HT3550.
You can inquire on the Steward thread on create a new one here:
Not many users are open to painting, but with paints you can create a custom shade that is positive gain but not artifact.
For that a thread can be created here:
Even the Cima Neve with it's slight increase will be beneficial. 0.1 or 0.2 gain means 10 or 20% gain.
To make sure you would have to get samples.