| ace3000_1 |
Heya peoples , just thought id start this up as ive just realised what we can do with loa's and an extra frensel while explaining about frensels to a few mates in the mirc chat room, if u get a loa and place it infront or behind a frensel and focus it to its focal point then that light it gathers from the loa becomes a point source of light, now i think doing this and running that point source from the loa through a condenser then through another frensel behind the lcd we can use loa's as a point source for projection, i have atached a pic below to show what i mean.This is just an idea and it should work, ive fooled with the loa i have and the beam to get it a point source but i havnt tried it for a projection setup but it does give us ideas. It is just a theroy for now.
Trev |
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| vudutek |
| seems possible, but wouldn't the extra focal lengths required result in a rather lengthy projector? |
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| ace3000_1 |
heya bud, yep it would forsure a waste of time realy but id thought id post the idea up for others to think in it. Maybe u could use a short focal frensel for the light collecting.
Trev |
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| vudutek |
hmmmm...
LOA> 9"FL fresnel> condenser> 9"FL fresnel> LCD> 13"FL fresnel> lens
might actually be on to something here.... between it being flourescent, and the distance required, heat sure wouldn't be a problem :) |
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| ace3000_1 |
ya mutible bulbs too to make a big light souce u could always use a mirror to bend the light before the condenser to make things abit more compact, i think it would work for a small lcd setup better with short focal frensels.
trev |
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| ace3000_1 |
| if u wer to make the loa source bigger and having the collecting frensel bigger and having that going through a longer focal condenser and a smaller collimating frensel then u could actually make the light brighter going through the lcd themn having a lcd equal in size to the light source, not realy feasable as in size but it would work |
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| 18wheeler |
| quote: | Originally posted by ace3000_1
Heya peoples , just thought id start this up as ive just realised what we can do with loa's and an extra frensel while explaining about frensels to a few mates in the mirc chat room, if u get a loa and place it infront or behind a frensel and focus it to its focal point then that light it gathers from the loa becomes a point source of light, now i think doing this and running that point source from the loa through a condenser then through another frensel behind the lcd we can use loa's as a point source for projection, i have atached a pic below to show what i mean.This is just an idea and it should work, ive fooled with the loa i have and the beam to get it a point source but i havnt tried it for a projection setup but it does give us ideas. It is just a theroy for now.
Trev |
:rolleyes:
I don't think it will work. you need to convert a non-point light source to a parallel source that can be collected to a point by the extra frensel. The problem here is how to convert a non-point light source to parallel. And if you can make it parallel, probably it is better to just use the parallel light onto LCD directly.
I know people will say we don't need to make it parallel, we just need collect enough light to the condensor lens. unfortunately those spreading light rays wont make their way to the lcd after condensor. Again, if the diagram works, we better off just direct the light directly towarding the LCD. |
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| jcbklyny |
| In theory it should work... but like wheeler said, you would be better off going another route. And I'm surprised your even bringing this up Ace. I know your into "small" diy projectors... and this idea would be anything BUT small :) |
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| ace3000_1 |
| quote: | | I don't think it will work. you need to convert a non-point light source to a parallel source that can be collected to a point by the extra frensel. The problem here is how to convert a non-point light source to parallel. And if you can make it parallel, probably it is better to just use the parallel light onto LCD directly. |
yep your probally right bud, i just thought id put this idea in here for others to try as in experiment, i see how fast things have come in here as of tech in the last 6months or so, we have come along way infact ALONG WAY! all of us, well mainly the ones who have stayed here i must admit, we have good light engines working out, different reflectors for different aps, better lighting systems, better optics and the construction of our projectors is alot better in technique and looks not to mention saftey lol, our home brew scratch built projectors way out do ohp's, and we made them from scratch! id like to see all of us get far with our ideas in finding an easy, fast and cheap solution that works for all of us in here, a comon parameter if ud like to call it, even though there is now id like to see a better one, jcb and myself have strayed abit with our projectors from the rest, and cruser no doubt, we are using some of the new ideas out of here but with our own light engine design and different materials, why this may not apeal to all to build projectors like ourself's we all learn from them at who evers exspence it maybe, and i think its great, even though we all argue from time to time lol atleast we are moving forward, this idea of mine is just an idea, and yess not very suitible but maybe we can learn from it to make a new design in a light engine, i think its possible, who knows maybe it would work with leds! or maybe we can squeaze even more light out of our mh system, who knows lets all see what the future holds.
Trev |
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| ace3000_1 |
| quote: | | In theory it should work... but like wheeler said, you would be better off going another route. And I'm surprised your even bringing this up Ace. I know your into "small" diy projectors... and this idea would be anything BUT small |
hehehe yeah man i know, just an idea, obviously not for us who use mh systems but maybe for those who want to use a LOA, im curious to see if it would work with leds, to see if it would combine the light into a bright point, even thought leds still arent bright enough maybe for the future.
trev |
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| nmd_sb |
| Yeah I was thinking about the LED point also, because I have this headband light, it has 4 bright LEDS, there is a low setting and a high setting, each LED has a reflector, and they are placed in a way the light converges to one spot, all 4 LEDs point to one spot. You can see a big bright circle, I guess the hardest part is positioning several to point to one point. |
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| VvvvvV |
how about making a pseudo laser like this... good space useage.
how mad is that... |
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| 18wheeler |
| I thought laser works like that before. but.... no, won't work. light exit the opening in a corn shape, and most light will be eaten by millions of times reflection. |
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| ace3000_1 |
can u even get white laser's? also i dont think they would work, its a totally diferent kind of light all together, its an inducted light from memory and has nothing to do with the natural light colour spectrum, if u get a laser pointer, shine it on the wall and look at the red dot u notice how different to light is and how anying it is, now if u got a white laser and ran that through a lcd im probally guessing it would look like **** cos of the different type of light, in laser it seems u can see the particles of light, in natural light u cant although in mh at 4200k it tends to make yours eyes abit funny looking at the light on the wall and u can see some particles if u look close enough but very fine, optics for lasers are very different also, they are specialised only for laser and the optics we use now for projection wont work how they are suposed to ie a fs mirror, laser is a totally different wave length, actually u could probally make a light pipe with a laser and some fiber optic to create a super bright back light, either way its interesting stuff.
Trev |
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| cohort36 |
Don't know if this will actually work in practice or not, but it sure looks like it will in theory. Just use a lens or mirror with a long focal length to focus the light to a point, then use another lens (another mirror may work, too) with a short focal length to collimate the light into a beam. The attached picture shows a long FL mirror with a short FL negative lens. The lens does not have to be negative, you can use a positive and just position it slightly differently. The width of the final beam is roughly the ratio of the short FL/long FL. ie, if the long FL is 10" and the short FL is 1", the final beam will be ~1/10 as wide as the initial beam. It can be done with a point source, too, it doesn't have to be parallel light coming in.
Does anyone know if this works in real life, or if it's just something that only works in theory? |
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| VvvvvV |
| i think that the output of the converging FL will be as wide as the width of the original bulb's direct beam. |
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| mikejz84 |
I already played around with reflectors for LOA--the results, nothing.
The problem with your model the beams of light are not coming off the bulb in any orderly pattern, they are going every which way and reflecting them is near impossible. |
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| ace3000_1 |
ya i knew somone would say that lol just a fast pic that was, to reflect difused light is near on imposible but it can be reflected, there is a special material that alows this and its not a point source reflector of such, the material is a alloy with a special coating, ive got some here just looks like mirrored ally but there is more to it then that for being able to get used for an loa. i take it your talking about my drawing mike.
trev |
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| nmd_sb |
| there's also something else, but it's very hard to get, a blackhole, it would suck in all the light and exit it out on the other end. :D |
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| ace3000_1 |
| hmmmmmmmmm try in outer space? lol actually dont they bend light backwards hence sucking it all out? |
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| nmd_sb |
lol :D , i dont know, I think it sucks everything in.
btw, what happened to the person that was going to dip their LOA in liquid acrlic? |
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