I Changing the focal plane of a video projection?

[wosoka]

A bit of unsual scenario, I need to divide a video projection beam horizontally into two. Since the splitted beams in my diagram are treated as a separate beam they have to have their focus plane changed. Is that possible to do and how would one do it?

http://image.ibb.co/jAu9x7/9241421.jpg

If this helps the resolution of the original beam is pretty low by todays standards, 856x480 pixels.

 

[sophiecentaur]

It would be hard to get into the internal optics of the projector but you could replace that 45° mirror with a curved mirror. However, the overlap between the two regions on the split image would be fuzzy. OK if you can do with an omitted part between the two images.
A large non-plane mirror could be hard to get hold of. Why not just use two video projectors, one with the left part of the image and the other with the right part?
More details of the actual setup could hep get a good answer to this.

 

[wosoka]

you can ignore the 45 degree mirror, it is irrelevant for the issue at hand

I don't want to describe the whole project with a wall of text just to ask a single question, but I can say that obviously the easiest solution would be to use two separate projectors if that was an option but sadly isn't

 

[sophiecentaur]

If you can't afford two projectors then I would say you definitely can't afford of the sort of optics to do the job with just one.
An alternative approach could to be to use two large flat screens in different places. That could be cheaper still and large screens are always useful to have, once you have bough them.
Or. . . could the projector be positioned strategically, at equal distances from both screens, with a bit of adjustment of the actual screen positions?

 

[wosoka]

It's not about not being able to afford projectors. The near-eye foveated screen project I am working on is complicated, it would take over 1000 words to describe it (which I know because I have it written down and can copy paste here), but do you really want that? Bottom lines is two projectors or flat screens won't work, if they could I wouldn't be wasting my time and complicating things.

 

[sophiecentaur]

It's not about not being able to afford projectors. The near-eye foveated screen project I am working on is complicated, it would take over 1000 words to describe it (which I know because I have it written down and can copy paste here), but do you really want that? Bottom lines is two projectors or flat screens won't work, if they could I wouldn't be wasting my time and complicating things.

A link to a 1000 word page would be quite in order on PF. People here tend to like information and background detail.

 

[wosoka]

Oh... give some time to generate a PDF with illustrations then

 

[sophiecentaur]

Oh... give some time to generate a PDF with illustrations then

Or some relevant links would do. From what I can see, we could be talking in terms of small, rather than large? That could make things different.

 

[wosoka]

Yup, pico projectors with a 30mm aprture beam and 1.2 throw ratio

 

[sophiecentaur]

Yup, pico projectors with a 30mm aprture beam and 1.2 throw ratio

That's good to know. So what else do we need to know?

 

[wosoka]

I think that's all, really. Two projectors are not suitable becaue of the extra weight and dimensions they would add and would be a waste of doulb the illuminating LEDs, DLP chips and projection optics.