UST focus distance

[Nojoy]

Hi all,

Used a WXGA Epson projector the past two years as a virtual matrix, and considering changing to an ultra short throw this year.

Never used one before, but read something I could use some clarity on: Do most UST have a distinct maximum focal distance?

i.e. most UST specs have an upper screen limit size (100/120/150 inch etc). Can you move a UST further away from screen to increase to 300+ and still achieve focus?

 

[Skymaster]

Personally I've never encountered any issues focusing to infinity on any lens, short or long, but the light output is the big issue. Double the diagonal distance is 4x the screen real-estate, and 1/4 of the brightness.

Borrowed this response from the AVSForums site---

Depends on the 'short throw' projector you are talking about. Some have optics which limit the capability to focus at about 100". Others hit 'infinity' and are pretty much in focus at any distance, but it becomes worthless because you would have a 600" diagonal and in a completely dark theater you still wouldn't have enough light on the screen for a usable image.

 

[Nojoy]

Thanks mate, yeah had seen that as well and that's what spurred the question. Lumen and environmental is controllable. If the unit physically can't focus beyond say 100 inch, it's not fit for purpose

 

[Skymaster]

Any way of contacting either Epson and/or the Lens manufacturer to get more detail? Or perhaps get a data sheet for it?