DIY Video Projector

[vdi_nenna]

http://www.lighting-optics.com/pdf/t...s_june2001.pdf

This is an excellent source of info! It's all drawn out for you!

[rjacobs]

Timo,

You could try the following address for Fresnel lenses (your German is a lot better than mine):

Fresnel Optics GmbH
Flurstedter Marktweg 13
Postfach 21-99510 Apolda
Thuringia, Germany
Tel: 49-3644-50110
Fax: 49-3644-501150

(Web: http://www.fresnel-optics.com )

Please let me know the results!!

Robin

[tim0]

Robin,

nice find.
I wouldn't know what to ask them at this time.
What do you want to know?
They seem to speak English too and even have a US division:

Fresnel Optics
1300 Mt. Read Blvd.
Rochester, NY 14606
United States of America
Telephone: 716-647-1140
Facsimile: 716-254-4940

I think the idea of finding an old projector and recycle the fresnel lense and projection optics is a good one. I'll check the newspaper for old OHPs from now on.

Regards
Timo

[rjacobs]

Timo,

I don't want to call the US division as we would have to pay in (expensive) US $ again :-(

The questions I have are:

1) Are they willing to deliver fresnel lenses to individuals?

2) How much do overhead fresnel lenses costs? (at least 30X20 cm big)

3) How much do rear projection tv fresnel lenses costs? ( at least 100 X 75 cm, preferable bigger)

If those big lenses are cheap enough a rear projection tv would be a very simple but nice start. take a normal TV/monitor (for example those old Commodore Amiga 1084S monitors are perfect!) put it in a big box with a big fresnel lens in front. It's like looking to a magifying glass. ( a example of what I mean can be found here: http://www.rickleephoto.com/rlcoll.htm , only our result would be a BIG screen TV)
I found several sites that offer 40X30 inch (100X75 CM)lenses for around $ 100,-
If we are able to order them directly from a factory in europe they should be a lot cheaper. (After all it's only a sheet of plastic)

I looked yesterday on one of those online marketplaces but I only found overhead projectors for about DM 200,- or more. I also found a LCD screen to be used on overhead projectors but it was back and white.

Robin

[daatkins]

Various sizes of fresnel lenses can be bought here:
http://www.lektropacks.co.uk/acatalo...evision_4.html

(I've never used them so can't comment on quality/service).

Regards,
DAve

[rjacobs]

thanks Dave,

The only problem there is (again) the currency. Currently US Dollars and British Pounds are realy expensive for mainland europe. ('cause of the weak Euro) but it seems a good source so I'll keep it in mind.

Robin

[tvi]

<a href="http://www.sciplus.com/category.cfm?subsection=21&category=193">American Science and Surplus</a> has these:-
(These were originally designed to fit over a TV to magnify the picture, and most have their original ’70s packaging.) The focal length of the lenses is 20”. The small lens is 7–1/2” x 10” wide. The medium lens is 10” x 13-1/2” wide. <b><u>They’re slightly tinted</u></b>, but that doesn’t affect their performance.

32571 FRESNEL LENS, SMALL $9.50/EACH
32572 FRESNEL LENS, MEDIUM $12.50/EACH



<center>Regards
James</center>

[Sawzall]

and being in the US, what the hell..

What should I take advantage of right now using my US bucks? What is a real steal if I am looking for big amp parts and sub drivers? Or hell, even new main speakers. Even if I have to buy it now and let it sit for a little bit. I have some friends in EU, so even purchase over there would not be a big problem if mail order was an issue.

Nothing lasts forever, so what should I take advantage of?

[tim0]

Robin,

i have asked the questions that you posted to the factory. Will let you know if they respond and what they have to say.

I don't want RPTV, but really a high quality projector with SVGA input. It must project a sharp image of at least 2x1.5m. I cannot fit a big RPTV in my room because there is a very big audio system standing in the way :-). One of the goals of this projector is to remove the PC/TV monitor+desk and replace it with a projector suspended on the ceiling.

Regards
Timo

[rjacobs]

Timo,

Thanks!

RPTV is not my first choice either, but the optics are so easy it can't go wrong.. (more or less..) If I can make a RPTV with decent quality i'm planning to cut a hole thrue the wall that separates my living room with the room that contains only my hot water boiler. Having only the 'screen' in the living room it would be like a plasma screen on the wall :-)

I just placed a bid on http://www.ebay.co.uk to a overhead projector plus a 640X480 LCD panel (with VGA & video inputs), it's not SVGA but good enough for video projection; this is not a DIY solution but for the current bid price it's a nice all-in-one solution for me.

I wish I could finaly find just some of these cheap page-magnifier sheets (in fact fresnel lenses) to play with. (and no I don't mean thrue a online store; I'm not willing to pay $ 2,- for the sheet plus $20,- for P&P, just a shop here in Barcelona where I can thouch and look at the sheets.)

Robin

PS: For the person in the US wondering what you could buy with our strong $$$'s : Just look for something what you want to have and order it, just beware that electrical equipment runs as 220-240 Volts/50Hz here (although many things could be adjusted to 110V/60Hz) and our television standard is PAL not NTSC. I've been told that what 'import' cd's are cheap here.

[Edited by rjacobs on 08-23-2001 at 07:27 AM]