Portrait (as opposed to Landscape) Aspect Projection, large screen, short distance

[Tapodhan]

I am looking to rear-project Portrait Aspect images onto a screen that is 108" tall and 81" wide. Because of available space the projector can be no more than 7 feet from the screen. I would prefer to do this using only one projector.
Any experienced advice re equipment, work-arounds etc gratefully accepted.
Alternatively, what are the options for using two linked projectors - one projecting the top half of the image and the other projecting the bottom half?
Hopefully,
Tap

 

[metti]

Re: Portrait (as opposed to Landscape) Aspect Projection, large screen, short distanc

You could do this with something like a Christie M series projector and their .73:1 lens. They are able to be used in a portrait configuration.

 

[Tapodhan]

Re: Portrait (as opposed to Landscape) Aspect Projection, large screen, short distanc

Thanks metti, but even the rental cost for that projector is going to be way out of my school's performing arts budget. Thinking about the issue further I realize that I could gain projection distance using mirror(s). That might increase the throw by up to 100%. Has anyone out there done that successfully? How?
A Sketch of my movable projection unit (with screen removed) is attached.

 

[ruinexplorer]

Re: Portrait (as opposed to Landscape) Aspect Projection, large screen, short distanc

Most smaller projectors are not supported by portrait mode. It is only recently that even the large frame projectors have been given the stamp of approval, with certain caveats. What I would look for is a projector that you shine straight down and then use the first surface mirror to angle the image into portrait. Are you looking to purchase or rent?

 

[LavaASU]

Re: Portrait (as opposed to Landscape) Aspect Projection, large screen, short distanc

How bright do you need this to be? If it's dark in the room a 9x ~6 screen is do-able with a home theatre projector. Most (none?) of those officially support portrait, but most will work fine if you don't mind reducing lamp and likely projector life. Its not hard to get a used 2-3k one for under $100.

 

[museav]

Re: Portrait (as opposed to Landscape) Aspect Projection, large screen, short distanc

Does the front of the projector have to be within 7' or the screen or is it that you have 7' of total depth including space for the projector itself and any ventilation requirements?

I have used mirrors many times for rear projection but you typically not only have to angle the mirror, you probably also want some adjustability to fine tune the mirror and projector relationships.

 

[metti]

Re: Portrait (as opposed to Landscape) Aspect Projection, large screen, short distanc

I have used mirrors in venues where the RP is particularly close to the upstage wall. One thing to keep in mind is that you are going to lose a fair amount of intensity unless you use a first surface mirror and in these sorts of very short throw applications you are going to end up needing a rather large mirror which is expensive and it can be a little tricky to keep it sufficiently rigid which is necessary for a distortion free image.