Here goes... this is what I've done so far in my attempt to build a projector... it's using a 15.4" proview LCD panel, and a 400w street lamp, and for now, OHP parts to test with. The OHP has a 355mm FL doublet lens, and when I tested with bare lenses only, it seems to have a very good FOV, if a bit blurry... here's the first test:
ShagMan said:The OHP has a 355mm FL doublet lens, and when I tested with bare lenses only, it seems to have a very good FOV, if a bit blurry... here's the first test.
nice test to test the the fov of the lens. You wrote the lens is 35cm EFL, but can you tell us the separation of the two outer candels? as well as the separation from the central candel to de projection lens optical center (let's say fisical center) and also the throw of that test? If you separated the candels until your subjetive maximal aceptable "critical" point, all this information could give you the field angle of this lens. So then you can check if the 15,4" with your desired throw will work or not.
Unfortunately I didn't do any precise measurements... the center "iris" portion is right in the middle, and the two lenses are just inside the short side of a CD case, that's what I used to hold them together The throw in that test was about 10'. I'd have to measure, but I bet it's seperated a little further in the actual OHP head... might ahve to take it back apart and make my own lens casing
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