Screen and gauze combination for back projection

[spotblaster]

A forthcoming play I am lighting requires darkness outside upstage windows and an opening door with occasional projected effects appearing in the gloom. Some of the effects will be done with moving and static lights and some with video projection. (Video projector 2600 lumens with wide angle lens hung above. Video material tweakable for maximum contrast).

 

It is proposed to hang a grey Rosco BP screen with a sharkstooth gauze hung in front of it about 1.5m upstage of the back wall of the set. Light can be kept off the surface.

 

The downstage lighting states will generally be quite dim. The play is set at night with gas lamps as the apparent source of light. The grey Rosco BP screen material has been chosen as it has a wider viewing angle than black.

 

The question I am seeking opinions on is the gauze. Would 8 point or 6 point be most suitable? Is the answer the obvious - a denser gauze would look better when it has to be black but the less dense one better when projection is in use?

 

Maybe I have answered my own question but any opinions would be appreciated.

 

Many thanks

 

 

 

 

Spotblaster

[groggy]

I'd request a samples of each and have a play around if you've got the time. Projecting onto a BP screen and with a gauze in front may have a strange effect for the audience. As the screen will become a light source and the gauze will muddy the image. if the content is bold and the detail is not hugely important then probably go with the 8pt as it will work better for gauze reveals. As you say in your post keeping light off the gauze and screen will have the most impact on your image quality.

[kitlane]

If you are front projecting then the 'strange effect for the audience' will be a Moire effect. The gauze will cast a shadow and the pattern of the gauze itself and its own shadow will give you a moire pattern.

 

I suggest you look at other screen manufacturers. Gerriets do some particularly nice, dark coloured screens.