Lumenlab > 1080p Optics.

Laser

Sep 1 2007, 03:55 AM

What I need...
I have most of the crucial components for my 15.4" 1080p setup (see below), but I need a little help with the Lenses. I want to spend as little as possible, without significantly compromising image quality. I thought about using a projection lens from an old CRT projector. For the moment, all I can say about the lens is that it's silghtly bigger than a CD (I can provide more info tomorrow). What are the chances of my being able to use this projection lens? I've read that the focal length has to match the fresnel, but why would that matter as long as the projection lens is large enough to "see" the fresnel?

Also...

QUOTE (jonjandran)

2.You can also use the Po lens kit from LL with the 15.4" WUXGA. And you an use an 18" Beseler Triplet wth the Pro Fresnels from LL. The 18" Beseler triplet can be bought from Ebay.

Would this be the right lens for a Beseler setup? And how does the Beseler compare(image quality-wise) to the Pro Lens, and the S15?

Any help/recommendations greatly appreciated.

Thanks

QUOTE

What I have so far...

I got a my 15.4" WUXGA panel here (LP154WU1-A1). It's a bit of a risk, but I've never heard of a cracked LCD that still displays a perfect image; it's gotta be the backlight diffuser ::crosses fingers:: (fyi, I'm getting it because of the 16ms response time; not the cheap price).

I'm getting the appropriate Realtek WUXGA controller (johnzo's a cool guy).

My 400W CoralVue ballast just arrived today.

I'm going to get the mogul socket from LumenLab.

I'm going to reuse the reflector from my OHP (I can't confirm the focal length, but it looks like the pro reflector).

I'm going to get the bulb from LumenLab. (btw, does anyone know if the LL bulb is a pulse start? or is it simply a known-working probe start bulb? Because I found a similar bulb on ebay for $20 but it's a probe start.)

pagercam

Sep 1 2007, 09:29 AM

QUOTE (Laser @ Aug 31 2007, 08:55 PM)

What I need...
I have most of the crucial components for my 15.4" 1080p setup (see below), but I need a little help with the Lenses. I want to spend as little as possible, without significantly compromising image quality. I thought about using a projection lens from an old CRT projector. For the moment, all I can say about the lens is that it's silghtly bigger than a CD (I can provide more info tomorrow). What are the chances of my being able to use this projection lens? I've read that the focal length has to match the fresnel, but why would that matter as long as the projection lens is large enough to "see" the fresnel?

Also...

Would this be the right lens for a Beseler setup? And how does the Beseler compare(image quality-wise) to the Pro Lens, and the S15?

Any help/recommendations greatly appreciated.

Thanks

Its really more about focal length than quality. those big CRT projection lenses ussualy are mounted either touching or 0.5 inch from the CRT so they have a very short FL and thus FOV (field or view) so they couldn't see anything more than thier diameter. The Pro or standard triplet should work fine, the Pro is a better lens
that the standard but the standard is good enough. The Pro has a Focal length of 500mm while the standard is 330mm (If I remeber correctly) so given the same distance to the screen the image from the stanndard would be 1.6 times bigger. For the same size image the Pro can be 1.6 times further away and thats the real reason to use the Pro get the PJ behind the viewer. You need to look at where you want to mount the projector, what area you have to project on and decide which works better. The Pro is probably better than a Beseler but not majorly so the Beselers are usually 18" or 450mm so this offers an in between size. Pro is required for 17"+ LCDs, some claim that the Beselers are fine for 17" while others say they can't get the corners, standard is pretty close to a 15", I think 15.4" is OK but you'd need to check that.

Distance to screen and screen size are the most important issues in finding the right lens.

Laser

Sep 1 2007, 03:50 PM

Thanks, that answers all of my questions.

I think I'll go the Beseler route for the longer throw without breaking the bank.