Transparent: Normally, transparent rear projection film can have a good effect in dark environment. It is transparent, so people can see things through the film. Also it will have a holographic image. But if the indoor light is too strong, the projection image can not been seen clearly.
Gray: Gray film can be used both in dark and light environment. And in both environment can achieve a good image. But people can not see things through the film.
Dark gray: Dark gray film has a high contrast then gray one. So it can be used in the strong light environment. Also people can not see things through the film.
1.Transparent rear projection film can have a good effect in the dark environment. As it have 92% transmittance, people can see things through the film,and it will have a holographic image. But if there have strong sunlight, the image projected can't been seen clearly.
2.Dark gray,grey,black film all are high contrast and can absorb the light,So they can be used under the strong light environment, the best opinion is high contrast grey.
Suggestions For Projector:
1.Any type projector all is suitable.
2.Projector lumens is more high,the effect is more better. But don't lower than 3000lumens(brightness).