DIY Video Projector Part II

[slize]

Funny -----> click

Propably not useable, but still funny .

i saw that on the german diy forum, and it started a VEEERRRYYYY long discussion if this will work...

but they ran out of it, so nobody could get and try it yet...

 

[mathias]

It woiuld be way better to use 2 bulbs on a normal 60deg prisim to combine the light into 1 beam and then we would have roughly 2x the light output.

Trev, I don´t understand how you can get that to work, so please explane that to me, because it´s not working for me.

Yep they will find it probably and will pay A LOT of money.

Slize, how are you going to solve the problem then ?

 

[ace3000_1]

Trev, I don´t understand how you can get that to work, so please explane that to me, because it´s not working for me.

Heya mathias, the 60deg prisim will invert the beam 10deg towards the center of the prisim to converge the light beam into 1, (you would think they would call it a 40deg prisim but its 60deg from the outer plane).

Trev

P.S i sent you an email did u receive it the otherday?

 

[slize]

Slize, how are you going to solve the problem then ?

probably by using mirrors

 

[mathias]

Trev, I'm sorry I still don´t understand it: What I can see, the only thing the 60 degrees prism is doing is changing place on the two beams they never get mixed. And if you change the angle on the lampbeam there will be rainbows.

Ps. I haven´t got any mail from you ?

 

[slize]

he was asking me if i got his mail

 

[ace3000_1]

he was asking me if i got his mail

Actually i asked both, mathais, that picture is wrong ill draw u one up, u dont get rainbows with white light nor with the right optics. The picture u have drwn up is 1 way of doing it though, but with a dichoric prisim with a beam splitter.

Trev

 

[ace3000_1]

Here is my pic mathias, its self explanitory so i dont need to explain, sorry for the crappy drawing lol.

Trev

 

[mathias]

Trev, what you have drawn is a mirrorprism, there is no way a glassprism can work in that way you have drawn. With a 60 degrees mirror prism the two beams will spread from each other. And the 45 degrees mirrorprism is not working either.

My conclusion is, there is no way to mix two beam with normalmirrors or prism. The only way to do it is with semipermeable material.

 

[The Alchemist]

What about using curved mirrors? When looking at a telescope i can think about a system like this:

An externally hosted image should be here but it was not working when we last tested it.

It's just a wild drawing in 2d, in 3d it will be not ok i guesh but maybe other non planer mirrors can be used?

 

[ace3000_1]

Trev, what you have drawn is a mirrorprism, there is no way a glassprism can work in that way you have drawn. With a 60 degrees mirror prism the two beams will spread from each other. And the 45 degrees mirrorprism is not working either.

mathias, the angle u have thought is wrong, its measured from a outer plane as stated earlier and its why i said i dont know why its a 60deg prisim when it should be a 40, the angles on yours are the wrong way round, BTW i like everyones drawings lol (makes mine look better lol)

Trev

 

[ace3000_1]

My conclusion is, there is no way to mix two beam with normalmirrors or prism.

Yup your right on that note, but depending on the grade we have our materials we can acheive things that the human eye can and cant see.

Trev

 

[mathias]

The angle u have thought is wrong, its measured from a outer plane as stated earlier and its why i said i dont know why its a 60deg prisim when it should be a 40

Okej, I think I understand what you mean, but with this the beams only cross each other, so the problem still remain.

 

[ace3000_1]

Ya and thats where u use a lens to corect this, u dont have to use a 60deg prisim, u could use a 46deg prisim, it all depends on how wide and where u want your light to go, but to get a strait beam u would have to use a corecting lens to convert the light so its paralelle, probally 2 condensers could do this, i havnt fooled around in this that much with any condensers so its realy only a guess at this stage, it should work though, it would have to be a double condenser setup i would think. But with this idea we can also use a frensel at the point of where the light converges, this will give us a point source, also u could use this with a normal condenser setup.

Trev

 

[mathias]

More lampmixers

After some thinking and calculation, I think I have a new idea of a lamp mixer with two 45 degrees glassprisms they are cheap and easy to find. The last prism is for colorcorrection of the first prism, otherwise there would be rainbows from one lamp.

 

[ace3000_1]

Mathias, a good rule to follow, what is on one lamp should be on the other, this will keep it eficient and help get the desired results, the last idea may work though, but u would need 3 prisims.

Trev

 

[mathias]

what is on one lamp should be on the other, this will keep it eficient and help get the desired results, the last idea may work though, but u would need 3 prisims.

I´dont know what you mean, you can always move the prism so the beams overlap each other and you can turn the last prism around. Why 3 prisms then I it´s work with 2 ?

 

[ace3000_1]

Sorry mathias i miss read your last post, but one thing that has got me curious is how can that work with one prisim having that degree of refraction while the other hasnt? wouldnt both sources of light have the same refraction difference on the 2 colour corrected prisims? they wont match up, and if only the prisim to the left is colour corrected, the prisim on the right has a big difference of refraction, its working as if its a lens.

Trev

 

[ace3000_1]

Why 3 prisms then I it´s work with 2 ?

Why 2 prisims when its the work of one? lol use a correcting lens after the prisim.

 

[mathias]

but one thing that has got me curious is how can that work with one prisim having that degree of refraction while the other hasnt? wouldnt both sources of light have the same refraction difference on the 2 colour corrected prisims?

The first prism (that with the green rays) give refration in one direction on the red rays, to correct this the last prism is turned in the other direction, so the refration take out each other. The green beam has no refration because totalreflection.

But one very strange thing with this design is that it doesn´t work in the other direction (backwards) ? So if there are anyone good at optic is this magic or what ?