I need some opinions on what optics will give me the best results (ss/sq) for my general layout, and what size screen should I set a goal for?
In the picture below you can see I have roughly an 8' by 12' wall to work with, and I want to mount the projector 16' away at a height of 6'
I was thinking a 15" LCD with a decent resolution and contrast ratio, a 250W HQI with a couple fesnels and triplet lens.
My source video will be digital cable tv, p-scan dvds, and a tv out from my computer when gaming.
The room is not dark, there is quite a bit of indirect/ambient light to hit that wall during the day, although I usually watch most tv and movies when the sun has gone down.
Thanks!
In the picture below you can see I have roughly an 8' by 12' wall to work with, and I want to mount the projector 16' away at a height of 6'
I was thinking a 15" LCD with a decent resolution and contrast ratio, a 250W HQI with a couple fesnels and triplet lens.
My source video will be digital cable tv, p-scan dvds, and a tv out from my computer when gaming.
The room is not dark, there is quite a bit of indirect/ambient light to hit that wall during the day, although I usually watch most tv and movies when the sun has gone down.
Thanks!
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OK then let me ask some smaller questions 🙂
If I use 4:3 aspect ratio for the DIY screen and have it 6' tall it would be 8' wide, so 8' x 6' = 120" diagonal right?
8'x6' with 120" diagonal is an ok size, yes?
In your opinion would a 250W HQI system from about 16' back give good results on that size screen?
If I use 4:3 aspect ratio for the DIY screen and have it 6' tall it would be 8' wide, so 8' x 6' = 120" diagonal right?
8'x6' with 120" diagonal is an ok size, yes?
In your opinion would a 250W HQI system from about 16' back give good results on that size screen?
I think what you should be concerned about is what type of projection lens you should use....I think at 16' throw, a regular plano-convex OHP lens would project your image too large...but others would be able to answer to that better....In fact I think you might just be at the cusp of getting an OHP to throw the size image you want at 16' throw.
The overall size of the screen you are wanting doesn't seem to be out of the ordinary in comparison to what has been done in the forum....Your throw distance might be a little longer than what regular OHPs have been throwing though...
Actually, the measurements you are wanting seem fairly close to what Proto5 was doing...(you might have a longer throw distance). Do a post search for Proto5.
Basically all this info is in the Forum...do a search on "throw" and whatever other relevant keywords you can think of, if no one else here wants to answer your question.
The overall size of the screen you are wanting doesn't seem to be out of the ordinary in comparison to what has been done in the forum....Your throw distance might be a little longer than what regular OHPs have been throwing though...
Actually, the measurements you are wanting seem fairly close to what Proto5 was doing...(you might have a longer throw distance). Do a post search for Proto5.
Basically all this info is in the Forum...do a search on "throw" and whatever other relevant keywords you can think of, if no one else here wants to answer your question.
ahh ok "throw" I will search for that
I was actually thinking of starting from scratch rather than from an OHP
the projection lens I was looking at was the one offered at diylabs http://people.eecs.ku.edu/~astaples/projector/lensinfo_triplet.htm
but I will ask him what sort of throw I could get out of that lens
thanks for the head start on my search
I was actually thinking of starting from scratch rather than from an OHP
the projection lens I was looking at was the one offered at diylabs http://people.eecs.ku.edu/~astaples/projector/lensinfo_triplet.htm
but I will ask him what sort of throw I could get out of that lens
thanks for the head start on my search
throw
Rhog:
Property is correct.....Throw distance is the bane of our existence here at DIY projector central.......All the OHP lenses (or the one you are considering) make the picture VERY BIG VERY FAST!!! My Elmo 305SD can fill my 8 x 12 screen when it it parked only about 8 feet away. You would think there would be an "easy fix" for this, like a reducer lens or something, but I haven't seen it yet.......let us know if you solve this "BIG" problem.
Rhog:
Property is correct.....Throw distance is the bane of our existence here at DIY projector central.......All the OHP lenses (or the one you are considering) make the picture VERY BIG VERY FAST!!! My Elmo 305SD can fill my 8 x 12 screen when it it parked only about 8 feet away. You would think there would be an "easy fix" for this, like a reducer lens or something, but I haven't seen it yet.......let us know if you solve this "BIG" problem.
do you know what this magic ratio is, or anyway to compute this if you have your distances with fresnel and projection lens focal lengths...
the size of the lcd would make a difference also, right? if someone is using a 7" compared to a 14" I would imagine this would "throw" off your throw distance
the size of the lcd would make a difference also, right? if someone is using a 7" compared to a 14" I would imagine this would "throw" off your throw distance
Re: throw
check this:
http://www.sciplus.com/singleItem.cfm?terms=1280
proto5 said:Rhog:
Property is correct.....Throw distance is the bane of our existence here at DIY projector central.......All the OHP lenses (or the one you are considering) make the picture VERY BIG VERY FAST!!! My Elmo 305SD can fill my 8 x 12 screen when it it parked only about 8 feet away. You would think there would be an "easy fix" for this, like a reducer lens or something, but I haven't seen it yet.......let us know if you solve this "BIG" problem.
check this:
http://www.sciplus.com/singleItem.cfm?terms=1280
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