Projector throw distance

[bazzy]

Hi
I have a projector I want to put into my spare room and set the room up as a home Cinema type setup. At the moment I only have a plus 5U-512h projector (will replace with HD probably 3D when it fails) the problem I am faced with is the picture size is only 120cm by 160cm. the projector cannot get any further back as it is hard against the wall now. It is from lens to wall is 280Cm.
The optical zoom of the projector is maxed out, is there a way to use some sort of camera lens to increase the throw of the projector? If I can get the image height from 120 to around 160cm it would be perfect, image width would be subject to height. The image it projects is usually smaller because most movies have letter box top and bottom.
Regards

Barry

[AzzA]

If you're playing media from a PC, you could use a zoom-able player (like Zoom Player) to make the most of what size you can project.

Get a good quality mirror, like an old mirror from a rear pro' TV, and use it to increase the throw distance... you'd have to flip the image horizontally (again, Zoom Player can do this or ffdshow etc) or use two mirrors if you can't. Sorting out the angles and dangles, and still being able to use the room, might be "fun" though.

[bazzy]

I was hoping to avoid using mirrors in that they would have to be rather large and would take a fair bit of space. not sure how it would work with a 3D projector down the track either.

Has anyone been successfull with using mirrors in a small room?

Regards

Barry

[Jalorathis]

When that projector dies and you upgrade, either purchase one with replaceable lenses. (Damn expensive)

Most projector lenses have a number on them somewhere, or the projo itself will. Yours appears to be a 1.75 ratio lense. (I'm assuming the 160 you mentioned is the width).
This means, the:
Width of image : Throw Distance
160 : 280
1 : 1.75

After a bit of comparison, you can work out that for a 4:3 image, you will need a screen width of 213.32cm for 160cm of height.
213.32 : 280
1 : 1.31

However, the image height will change drastically when you get a HD projector. However, to maximise usage, you will need a 1.31 or lower lense ratio.

These do exist, at work we have lenses for the old crappy LP850 projectors down to 0.8.

These are non-zoomable, but we can project a 20ft wide image from 16 ft away.

More info if you like:


Hope this helps a little.

[bazzy]

I ended up replacing the projector with a 3D ready projector that has a good throw ratio

Am going to use the other one to project into my out door area.

Regards

Barry