Short-Throw Projectors

[orwell84]

!5 feet of throw distance? Throw distance and projected image size are the factors you want to consider. The projector people website has a calculator to figure this out. 15 feet of throw distance is a lot. I looked at this projector, but will probably vgo with the Optoma you mentioned. It gives and 8 foot wide image at about 5 feet of throw distance. This is about all the space I have.

[Sean Nixon]

My throw distance will be somewhere around 6-8ft. It's the width that's 15ft (the width of the screen). I plan to use 3 projectors/TH2G/Sol7/curved screen.

[orwell84]

Check out www.markuspilot.com. He has a good description of a 3 projector setup with dimensions that are similar to yours.

[BHawthorne]

!5 feet of throw distance?

Yep, short-throw has good points and bad points. The lens is a bit extreme on the short-throw, but to get the projection height I wanted within a reasonable room size short throw or mirrors are required. I don't want to screw with first surface mirror mounting and alignment, so that limited me down to short-throw. Roughly I have my projectors currently mounted around 6 foot throw distance at the moment. That allows for plenty of projection height to ensure immersion factor is there. The extreme short-throw lens is what accentuates that bow in the curved screen, so there are trade-offs here. There are plenty of examples of people using mirrors but that is another layer of alignment and mounting headaches to deal with. I'd rather keep things simple as possible. As is there are several layers of complexities to deal with in this new hobby projection technology. I didn't want to add anymore more valiables than I had to into the design.

Check out www.markuspilot.com. He has a good description of a 3 projector setup with dimensions that are similar to yours.

Yep, looks pretty comperable to mine. Using both Sol7 and a simular triple mounting configuration. A bit more permanant of a screen design though. My screen design is a lot cheaper and can be taken down in about 15 minutes notice. While the room is a dedicated gaming room, I wanted the ability to put up and take down the screen as needed. Painters drop canvas works great for my current needs. It's good to see different examples of screen design. Depending upon your goals you have several potential design options.

[Spatate]

And what about a short throw combined with a fresnel lens that you curve?

Sol7 would correct the distortion no?, wouldn't allow it to use less than 3 projectors?

[BHawthorne]

And what about a short throw combined with a fresnel lens that you curve?

Sol7 would correct the distortion no?, wouldn't allow it to use less than 3 projectors?

How would you encorporate an fresenel lens into a projection setup?

[Spatate]

How would you encorporate an fresenel lens into a projection setup?

Here's my idea...

[BHawthorne]

Here's my idea...

Hrrrm, anyone want to buy me an optical quality fresnel lens so I can test this and post the results? Xmas broke me for this month.

On a related note, optical mylar sheet is also capable of convex and concave anamophic shaping. I have the mylar from an old back projection big screen tv someplace to also play with as a shapable first surface mirror.

[kelvinlars]

Really very good idea..

[Spatate]

Fresnel is not very expensive.... here's a supplier

http://www.3dlens.com/shop/fresnellens.php

Cheers