Finally gathering the parts to build a projector, and now it's fresnel time. I'm building two projectors. (One for me, one for mom)
One will have a 450mm long throw lens, and thus I will be using a 550mm fresnel. The other will be using a 230mm lens, and thus the fresnel for it will need to be a 230mm.
My confusion, however is for the rear fresnel. I know it's supposed to be placed a distance equal to its focal length from the point of the light source, but I don't know which focal length I should get. The primary options seem to be 230mm or 330mm. Does one work better for smaller setups, or does it even matter which size I get?
Also, if I use mirror(s) in my design, then I assume the mirror(s) should be placed at focal length distance from both the light/fresnel and/or projection lens/fresnel.
I thank any and all for assistance in my questions and apologize if I've asked anything that would be easily found. (I tried, but couldn't find anything. Had some problem with the search tonight when looking for any reference to a HP LCD)
One will have a 450mm long throw lens, and thus I will be using a 550mm fresnel. The other will be using a 230mm lens, and thus the fresnel for it will need to be a 230mm.
My confusion, however is for the rear fresnel. I know it's supposed to be placed a distance equal to its focal length from the point of the light source, but I don't know which focal length I should get. The primary options seem to be 230mm or 330mm. Does one work better for smaller setups, or does it even matter which size I get?
Also, if I use mirror(s) in my design, then I assume the mirror(s) should be placed at focal length distance from both the light/fresnel and/or projection lens/fresnel.
I thank any and all for assistance in my questions and apologize if I've asked anything that would be easily found. (I tried, but couldn't find anything. Had some problem with the search tonight when looking for any reference to a HP LCD)