Look at this guys projector: http://www.allinbox.com/freebox/freebox.htm
Why does he have his projector behind the seating area and what looks like about a 12 foot throw on a 8 foot screen with 15 lcd screen. I looked into where he claims he got his objective. He doesnt mention the focal of his objective but it does not look like its longer than 350mm.
Why does he have his projector behind the seating area and what looks like about a 12 foot throw on a 8 foot screen with 15 lcd screen. I looked into where he claims he got his objective. He doesnt mention the focal of his objective but it does not look like its longer than 350mm.
physics are physics!
If he really is projecting a 15" LCD to make an 8' diagonal image from a 12' throw, then he has around a 500 mm fl projection lens. I suspect your distance estimates are a bit off, and he really has one of the standard 480 mm fl triplets.
This is why people make long-throw projectors: So you don't have to struggle to see around the projector box that is sitting in the middle of the room.
If he really is projecting a 15" LCD to make an 8' diagonal image from a 12' throw, then he has around a 500 mm fl projection lens. I suspect your distance estimates are a bit off, and he really has one of the standard 480 mm fl triplets.
This is why people make long-throw projectors: So you don't have to struggle to see around the projector box that is sitting in the middle of the room.
480mm FL standard triplet? To my knowledge the only long triplet that exists are the large 135mm diameter ones sold at LL, DPC or opaque projector lenses. Take another look at the photo. Looks like a small diameter lens to me.
http://www.izzotek.com/objectifs.htm
That's where he said he got the lenses from, can only find a doublet of 400 mm, and triplets of 345, 300 and 265 mm as well as a few varifocals
That's where he said he got the lenses from, can only find a doublet of 400 mm, and triplets of 345, 300 and 265 mm as well as a few varifocals
looks like a smaller lens to me
Maybe it is a process lens. It looks like many of them I have seen. They are always pretty short, since they have such wide FOV.
But there really is no way to escape the physical laws: If he has those sizes and distances, his lens fl is around 500 mm. Why don't you see if you can ask him by email?
Maybe it is a process lens. It looks like many of them I have seen. They are always pretty short, since they have such wide FOV.
But there really is no way to escape the physical laws: If he has those sizes and distances, his lens fl is around 500 mm. Why don't you see if you can ask him by email?
- Status
- Not open for further replies.