DIY-Projector Plans and theory collection !!

[ace3000_1]

The ellipticalreflector design is used in all modern slideprojectors with a lamp of the type ELC A1/259 with built in reflector. And the other designs use the normal ohp-design.

There is not 1 eliptical reflector in your design, eliptical reflectors have 2 focal points, i only see a wide angle spot reflector, a spherical reflector and a parabolic reflector in your drawings.


Eliptical reflector:

[ace3000_1]

Here is a little somthing for hezz to help him along his way with his lens design.

http://wwwhip.obspm.fr/gaia/rvs/work...mla_optics.pdf

[mathias]

There is not 1 eliptical reflector in your design, eliptical reflectors have 2 focal points, i only see a wide angle spot reflector, a spherical reflector and a parabolic reflector in your drawings.

As you can see in the picture the reflector I use and show in my slideprojector designs is a ellipsoidal reflector and the light beam out of it is parallel and this type of reflector is very common in searchlight. I really don´t understand why you write things that is not true.

[mathias]

There is no way u will get rays out of a positive power lens in the way you show it, paralelle or non paralelle light, the light will go to the focal point of the lens.

You have also wrong in this statement, positive lenses work exactly as I have drawn.

[ace3000_1]

Mathias for your post above they are double convex lens, they are not plano convex in what im talking about and they are used as condenser's, if u want to argue on the truth, then dont argue with me, my information is from optical engineers who have phd's in all areas of optics, and this information come from the net acociated to their knewlege, for the record eliptical reflectors dont put out paralelle light and all have 2 focal points as i have stated above with the atached image, that image isnt draw by me btw. So now its upto you to find the truth and do the study for yourself, ive done the study ive contacted who i have had to contact and i know the truth, no guesses but answers from optical engineers who have studdied over this complete matter.

Trev

[ace3000_1]

Mathias, read this page, look at light, its an eliptical reflector and with the coresponding 2 focals, in the diagram that shows the 3lcd's its clear how it works, it is also clear that your angles are incorect from the condenser to the frensel, so maybe an apology may be in order.

http://www.extremetech.com/print_art...15893%2C00.asp

Trev

[mathias]

I have drawn normal positive lensen because it´s more easy to draw. There are not any diffrence between double convex lenses and plano convex more then plano convex have better optical quality.

Eliptical reflectors actully give parallel light, if you move the lamp backward in the reflector, this is how all searchlight works, if you don´t beleave me, try it yourself !

If you got your information from a optical engineer I think you have misunderstand him a lot, I have myself read many books from the University about optics and I am a enginner myself, and I think it´s unfortunately that you say people have wrong when you don´t really know that.

[ace3000_1]

Mathias, i realy dont know what your problem is, i see you cant admit to being wrong, my proof is in the pages that ive posted and is very clear, so realy if you take a look at the odds, then your the one who realy needs to read and to realise where you have gone wrong. Ive tried to help you mathias to show you where you are wrong but you cant acept the truth, it is now not my problem and i will not discuss this matter further with you.

Trev

[mathias]

I don´t understand why you have so hard to understand. That page you linked to prove that you get parallel light out of a eliptical reflectors. When they move the lamp backward in the second picture they get the focus on a longer distance from the reflector. What do you think happen when they move it more backward ? Maybe parallel light ?

And I haven´t any problem more than I want people to know the truth !

But thanks for the link, it helps me with my pro-projector.

[ace3000_1]

mathis, they arent after a paralelle light read the link again, if they wanted paralelle light they would use a parabolic reflector.