Projectors and mirrors

[Spider_senses]

has anyone tried to reduce the throw distance to size of projection ratio by reflecting it off a mirror? I can't afford a projector with a wide angle lens, what kind of loss in Lumens will I suffer by doing this?

[Grahame]

Yes, managed to do it once with reasonable success. I can't give you definitive figures on loss of lumens; obviously there was some loss but it was still workable. The main problem is that you need a pretty big mirror to seriously reduce throw distance. Think about the size of your desired final image. Then think about how much space you need for that throw. To make any serious difference to the throw distance, your mirror is going to have to be about half the size of your final image. That can be very unwieldy to work with if your final image is large.

You may also have to think about keystone correction to avoid a distorted picture, and many cheaper projectors don't include this facility.

 

~Grahame

[robloxley]

Yes, this is a common solution to short throw distances. You will however need quite a large, front-silvered mirror (to prevent double-reflections and blurring) which aint cheap. You will probably find that wide angle lenses are a cheaper option.

[tony]

have used a mirror quite often

good results as long as you don't have text just using a standard mirror

if you need good text then you need a true mirror which costs

 

good luck