Man, I knew you guys would have the answers!
Let me see if I can answer all the questions
drgeoff wrote:But I presume you want some sort of image on the screen. What is producing the image you want projected and where is it in relation to the lens?
drgeoff wrote:If it is then his discussion mentioning screen size is confusing when the word "screen" in the context of "projector" usually means the large white area that the viewed image falls on.
Yes, my apologies I am overloading my variables
Let me clarify.
I'm making a diy projector, I've chosen a 10.1" 1920x1200 LCD "screen" (which I will just refer to as the LCD panel from now on to avoid confusion with the actual screen that I will be projecting the image onto). The specs claim the viewing area is 9x6", so half my vertical viewing angle is where I got the 4.5" number from.
My light source is a 100w cool white LED. I know that I should have my LED an equal distance from the collimator's Focal length, but I have not been able to get a firm grasp on how I'm supposed to choose that focal length. Do I want to place it such that the LED's view angles perfectly hit the top and bottom of my Fresnel lens? Or should I just blindly follow all the guides I've seen out there and use a 220mm Focal length for the collimator?
So my build will be Light source (100w LED with a reflector) -> a distance equal to my collimator focal length (which is what I'm trying to learn how to calculate) -> collimator -> LCD panel -> condensor w/ 330mm focal length -> Triplet lens
I've thought about putting a piece of glass between the LED and the collimator as I've seen recommended with using other light sources to protect everything else from the heat of the light, but the LED shouldn't put out that much heat (well it shouldn't radiate that much heat, it will need a heatsink of its own)
toxibunny wrote:The lumenlabs forums used to be the best place to ask, but since cheap projectors became available, they lost a lot of relevance...
They are completely gone, in fact, much to my horror. I tried asking about this over at diyaudio in their projectors subforum, but no one is talking. I mean not even a derisive "can't you google this?" response, just pure crickets!