Call me crazy but...

noodles · 11th August 2002, 08:25 AM

I know how you people hate the 100" TV thing, but would it be possible to scrap the fresnel and lenses from my OHP and put them on my old computer monitor? I'm thinking it won't get much light (what I've heard about the TV).

noodles · 11th August 2002, 10:18 AM

I just "tried" it out. I have no clue what focal points are. But I tried a number of things. First, I made a cardboard box to go around the monitor. Then I put the fresnel at the end of the box (45cm long). It could project a 3 inch image to a sheet of paper I was holding in front of it. Then I cut the box in half and put the fresnel on it. It could project a bigger image, but it was really blurry. Then I just said screw the fresnel, and I put an OHP lens in front of it. It projected a fairly big image (3'x4') on my wall, but there was practically no color at all. I'm guessing the fresnel will direct the light straight into the lens and make it all nice and nifty. I wouldn't know. It's 5am.

noodles · 14th August 2002, 04:40 AM

um.... yeah. I figure my old PC monitor isn't bright enough. I held my projector lens by the tv and I got a huge screen with kinda pale color. So I figure I can box it up, and it'll be decent. Just experimenting with optics in general (is that the right word?).

the whinner · 14th August 2002, 06:26 AM

noodles!

i tried the same thing one year ago, and get the same results!
the fresnel on OHP is doublet, it is two fresnels glued together, so you cant use it for this. try to put ordinary page magnifier with bumpy side towards the tv screen instead of OHP fresnel, combined with OHP magnifier (the one from OHP's arm)!

the reason you are getting pale image is that OHP magnifying lens has small diameter, so there is not enough light passing through it! try to move tv closer to the wall, you will get smaller, but brighter image!

or use the lens from opaque projector, it is basicaly the same as OHP lens, only much bigger, and it will give you much brighter image!

noodles · 15th August 2002, 04:56 AM

Update: I took my brother's tv

and I'm using the magnification lens and mirror from my OHP. I'm watching Chasing Amy widescreen on it right now and my guesstimate is that it is 10'x5'. That doesn't sound like the right proportions, but it's still sweet. The picture is still a bit blurry (understood, seeing as how this method is GHETTO!). The blurryness won't be much of a problem when I adjust it and whatnot. I'm still fiddling with the pale thing. The TV is way better than the monitor though.

11th August 2002, 08:25 AM	#1
noodles diyAudio Member Join Date: Jun 2002 Location: Gulf Coast, Punk	Call me crazy but... I know how you people hate the 100" TV thing, but would it be possible to scrap the fresnel and lenses from my OHP and put them on my old computer monitor? I'm thinking it won't get much light (what I've heard about the TV).

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
what do you call this stuff.	neutron7	Everything Else	4	8th August 2007 09:16 PM
I don't even know what to call this-	Conrad Hoffman	Everything Else	16	24th June 2007 04:11 PM
call me embarassed!	shepperd	Class D	2	6th February 2007 09:56 PM
New England Roll Call	speaker	Everything Else	9	3rd April 2004 09:56 AM
Call me stupid, but.....	LNeilB2	Multi-Way	7	28th January 2003 05:55 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

11th August 2002, 10:18 AM	#2
noodles diyAudio Member Join Date: Jun 2002 Location: Gulf Coast, Punk	I just "tried" it out. I have no clue what focal points are. But I tried a number of things. First, I made a cardboard box to go around the monitor. Then I put the fresnel at the end of the box (45cm long). It could project a 3 inch image to a sheet of paper I was holding in front of it. Then I cut the box in half and put the fresnel on it. It could project a bigger image, but it was really blurry. Then I just said screw the fresnel, and I put an OHP lens in front of it. It projected a fairly big image (3'x4') on my wall, but there was practically no color at all. I'm guessing the fresnel will direct the light straight into the lens and make it all nice and nifty. I wouldn't know. It's 5am.

14th August 2002, 04:40 AM	#3
noodles diyAudio Member Join Date: Jun 2002 Location: Gulf Coast, Punk	um.... yeah. I figure my old PC monitor isn't bright enough. I held my projector lens by the tv and I got a huge screen with kinda pale color. So I figure I can box it up, and it'll be decent. Just experimenting with optics in general (is that the right word?).

14th August 2002, 06:26 AM	#4
the whinner Account Disabled Join Date: Jul 2002 Location: belgrade, yugoslavia	noodles! i tried the same thing one year ago, and get the same results! the fresnel on OHP is doublet, it is two fresnels glued together, so you cant use it for this. try to put ordinary page magnifier with bumpy side towards the tv screen instead of OHP fresnel, combined with OHP magnifier (the one from OHP's arm)! the reason you are getting pale image is that OHP magnifying lens has small diameter, so there is not enough light passing through it! try to move tv closer to the wall, you will get smaller, but brighter image! or use the lens from opaque projector, it is basicaly the same as OHP lens, only much bigger, and it will give you much brighter image!

15th August 2002, 04:56 AM	#5
noodles diyAudio Member Join Date: Jun 2002 Location: Gulf Coast, Punk	Update: I took my brother's tv and I'm using the magnification lens and mirror from my OHP. I'm watching Chasing Amy widescreen on it right now and my guesstimate is that it is 10'x5'. That doesn't sound like the right proportions, but it's still sweet. The picture is still a bit blurry (understood, seeing as how this method is GHETTO!). The blurryness won't be much of a problem when I adjust it and whatnot. I'm still fiddling with the pale thing. The TV is way better than the monitor though.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)