Hi,
I'm throwing around lots of ideas at the moment on how to make my projector as less-a eye sore as possible, and so I need some help.
I've included a rough diagram of the basic theory behind my design and need to know, is there any lens that will bring in all the light which is converging inwards from the fresnal, and straighten it into a beam, while maintaining accurate colour representation, etc. and not mixing up the light.
In the pic I've explained it better. The light is yellow, the fresnal and convex lens are white, and the unknown lens is red.
For those who are saying to themselves, "Huh?!? Why does he want a narrow light like that? How will that give him a big image?" or those who have seen past that though and realise that that light flow will not be aimed at the screen, but still are curious as to why I want to know this (*phew*) then this is why,
DIY projectors, especially those with a design such as mine, do not look all that pretty. Many people design them however to blend into their environment in the form of furniture or possibly even use the mark 2 design from diylabs.org to turn it into a coffee table with a lens poking out (not that I've ever heard of people doing that, but I just had that thought, feel free to try it out), I even heard of one person wanting to turn theirs into a big fake grandfather clock. But anyway, my idea is to maybe hide the large projector out of view, or turn it into a piece of art and then have tubes running across the wall, directed by mirrors, and finally end up being sent through a zooming lens and onto the screen. This is because I have little room and so even saving say 15" of space will be a lot. (In effect looking just like a lens coming out of the wall).
Thanks for your help
I'm throwing around lots of ideas at the moment on how to make my projector as less-a eye sore as possible, and so I need some help.
I've included a rough diagram of the basic theory behind my design and need to know, is there any lens that will bring in all the light which is converging inwards from the fresnal, and straighten it into a beam, while maintaining accurate colour representation, etc. and not mixing up the light.
In the pic I've explained it better. The light is yellow, the fresnal and convex lens are white, and the unknown lens is red.
For those who are saying to themselves, "Huh?!? Why does he want a narrow light like that? How will that give him a big image?" or those who have seen past that though and realise that that light flow will not be aimed at the screen, but still are curious as to why I want to know this (*phew*) then this is why,
DIY projectors, especially those with a design such as mine, do not look all that pretty. Many people design them however to blend into their environment in the form of furniture or possibly even use the mark 2 design from diylabs.org to turn it into a coffee table with a lens poking out (not that I've ever heard of people doing that, but I just had that thought, feel free to try it out), I even heard of one person wanting to turn theirs into a big fake grandfather clock. But anyway, my idea is to maybe hide the large projector out of view, or turn it into a piece of art and then have tubes running across the wall, directed by mirrors, and finally end up being sent through a zooming lens and onto the screen. This is because I have little room and so even saving say 15" of space will be a lot. (In effect looking just like a lens coming out of the wall).
Thanks for your help
Attachments
I've been thinking same kind of system myself.
For optics see http://physics.bu.edu/~duffy/java/Opticsa1.html
It's a small java applet that lets you mess with optics.
There is also a free program called OSLO Edu or OSLO LT.
LT can be found from Sinclair Optics, http://www.sinopt.com/
and Edu from Lambda Research, http://www.lambdares.com/
From Lambda they also sent me a demo of TracePro.
For optics see http://physics.bu.edu/~duffy/java/Opticsa1.html
It's a small java applet that lets you mess with optics.
There is also a free program called OSLO Edu or OSLO LT.
LT can be found from Sinclair Optics, http://www.sinopt.com/
and Edu from Lambda Research, http://www.lambdares.com/
From Lambda they also sent me a demo of TracePro.
Can't help you much with optics, but personally, I've got a design in my head to make the thing look nice. I'm reading a book about composites, and I plan on refitting my projector into a slick carbon fiber frame. Of course it will still stand out, but it will look very sleek and stylish. As good, if not better, than a real projector.
extin,
thanks. I have noooo idea what I'm doing with the java applet tho. 😕
Lifter,
yeah I was thinking of making a super duper cool enclosure for it, but that then gave me this idea. I was thinking, being a fan of Dragon Ball Z (the most mature cartoon ever!!!!!), that I would make an enclosure that resembles one of the characters, and the light would come out like their fireballs do, out of their hand, etc.
But then I remembered how lazy I am and so decided to do a tubing projector. Then I'd be able to get the light outputted higher and therefore have better image positioning.
Thanks for your replies
thanks. I have noooo idea what I'm doing with the java applet tho. 😕
Lifter,
yeah I was thinking of making a super duper cool enclosure for it, but that then gave me this idea. I was thinking, being a fan of Dragon Ball Z (the most mature cartoon ever!!!!!), that I would make an enclosure that resembles one of the characters, and the light would come out like their fireballs do, out of their hand, etc.
But then I remembered how lazy I am and so decided to do a tubing projector. Then I'd be able to get the light outputted higher and therefore have better image positioning.
Thanks for your replies
Just add light source and lenses, then adjust the focal lenghts so that you get what you want. I don't know what units the applet uses. But it should give you a clue of how to make it work.
Hmmm,
ok thanks.
I've given it a little play with and seem to have made a straight beam. Now if only I knew how to make it a reality.
ok thanks.
I've given it a little play with and seem to have made a straight beam. Now if only I knew how to make it a reality.
(In effect looking just like a lens coming out of the wall)
This is a goal I hope to achieve also. To that end I've bought a lens from a photo enlarger. The lens is 9 inchs across by 3.5 inchs thick. In the photos the focal length is indicated as 8 inchs, from the specs I found for my 3M my triplett is at 14 inchs f/l. So either I've just shaved 6 inchs off the total "depth" of my projector...or I've got a REALLY cool lens to play with for 50 odd bucks 😉
If this monster is useable I've got the mounting job of a lifetime to do, it weighs in at just over 10 pounds.
zardoz
This is a goal I hope to achieve also. To that end I've bought a lens from a photo enlarger. The lens is 9 inchs across by 3.5 inchs thick. In the photos the focal length is indicated as 8 inchs, from the specs I found for my 3M my triplett is at 14 inchs f/l. So either I've just shaved 6 inchs off the total "depth" of my projector...or I've got a REALLY cool lens to play with for 50 odd bucks 😉
If this monster is useable I've got the mounting job of a lifetime to do, it weighs in at just over 10 pounds.
zardoz
Hi Morien,
basically the red lens is your objective lens. You can't have parallel rays out from your lens, because you need light beam spread as big as your projected image, if your light beam smaller than your projected image, it will generate hotspot, if bigger, than you get washed out projected image. Rule of thumb is: your fresnel panel focal length X 2 = LCD panel to lens distance X 1,33. I have the problem of this kind, see my thread: forget fresnel panel!
see you...
basically the red lens is your objective lens. You can't have parallel rays out from your lens, because you need light beam spread as big as your projected image, if your light beam smaller than your projected image, it will generate hotspot, if bigger, than you get washed out projected image. Rule of thumb is: your fresnel panel focal length X 2 = LCD panel to lens distance X 1,33. I have the problem of this kind, see my thread: forget fresnel panel!
see you...
Gunawan, a little off topic, but I was reading your "forget fresnel" thread, and I remembered that YWH figured out that placing a eyeglasses lens (a certain perscription, forget what exactly) in front of the projection lens will increase the focal length and allow you to move the projecter further away from the screen.
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