Hello all,

I'm still in the "planning phase" for my PJ.
I'm going to build a 17" straight light path PJ.
I know that there are focus issues when using the 80mm 330mm-FL triplet with a 17" panel...

Is there a lens out there that will focus edge to edge with a 17" LCD?

I'm wondering if such a lens is available at a reasonable price anywhere?

Any and all info is greatly appreciated.

Thanks, Davide-NYC

Do you want your projection 14' wide, or 14' diagonal?

For 14' WIDE, the standard triplet isn't too far off. I know that others have used the standard triplet with a 17" LCD, and in fact, by this time next week, I may be doing that myself. (My 15" LCD is cracked, and I'm fed up with trying to find a reasonably priced alternative. I have 17" LCDs already, so I'm going to use one, provided that I can get it to fit in my box. I think it's going to be close, but doable.)

Hi Supraguy,

I know this can be done but there are focusing problems in the corners using the standard triplet.

What I'm wondering is if there exists (anywhere and for any price) a lens that would properly focus a 17" (or larger) display panel corner-to-corner with SHORT THROW.

I'm talking 14' width (even 16' width) !!!

I've done a ton of research about all of this, including you PLOG.
I know all about destructo-kitty. I have three! WATCHOUT...

A 14 foot projection would probably be the equivilent of a 12 foot projection with a 15 inch panel as far as brightness. But really I think at 14 feet you'd be forced to sit back so far to prevent the screen door effect that you might as well decrease the projection size to save space and gain brightness. I'd reccomened somewhere betweeen 7 to 10 feet.

Matropolis has done it. I intend to, if I can resolve soe issues with LCD mounting.

Ahhh! Screendoor Effect. Yes.
I had not thought of that.
Thanks for the info Mikau.
I am one step closer to starting now.

But the question remains:
Is there a lens that will work (at whatever price) for >=17" panels using the frensnels that are available?

D.

Hmmm I dont undrstand why some to think there are probs using 17" lcd,s with full standard LL lens sets
I dont find any probs with brightness or focus,, even had 15" PJ side by side with 17" in fact mine was sharper overall

clive..

OK, so you're saying no blur in the corners on a 17" panel?
This contradicts what I've read before, but I see yuor result and am impressed.
Could you post (either here or on your PLOG) a pic of some text in any (or all) of the corners?
I'm diving in Nov 1st!
D.

If money is no probllem their is a good chance you could fing a process lens on ebay many go for $300 or more so most and say what the FOV is and the FL .
some call them cookie lenes.

Davide-NYC if money is no problem and you don't have your monitor yet have you seen this group buy for a 15.4 WXUGA panel which you can use the standard lens kit.

http://members.cox.net/minoten/

someone at DIY PJ said they have used a 3M 9800 OHP triplet and was sharp to the edge on a wide 17' lcd the triplet has a 342mm FL so you could buy and scrap a 9800 OHP or find someone who will sell replacment parts it realy shoulden't cost more than $60

here's a lens that might work it sure looks impressive it's huge! 400mm fl and the clear diameter is a at least 5-10 mm larger than the standard LL triplet (I know, I have both). you could pair it with the 450mm fl fresnel group buy at diyprojectorcompany.com the fresnel would cover the entire screen and then some. Or maybe you want to wait a bit for the LL Pro Lens.

I've seen that lens before during my compulsive escapades researching on LL and DPC and all over.

Do you know if the FOV is enough to get corner 2 corner focus at 400~450mm on a 17" LCD?

Here are my key points:
1. I want even light across the whole image.
2. I want corner-2-corner focus.
3. I want 1280x1024 resolution.

I also would really like a HUGE image and I have a 16'x12' flat white wall @ 16' distance that is just begging to be filled with cinematic goodnes.
But I've come to the realization that SIZE is not as important as QUALITY.

Question: Is this copy lens the lense for me? Is it the standard triplet? Is it the 135mm DPC lens?

I just know I'm going to end up with a pile of extra fesnels and lenses no matter how much research I do.

Your wants are not possibe at the moment using a 17" monitor. They are very close to attainable with minotens UXGA 15.4" setup, but thats not 1280x1024. They are theoretically attainable using a pro setup but I wouldnt hold your breath.

With a 17" setup using standard triplet and larger fresnles:

1. You'll get lighting good enough as to not notice in movies unless there is a scene with uniform colour (never happens).
2. You'll get focus good enough not to notice on a widescreen movie, but apparant on a 4:3 windows image in corners.
3. Easy done with any 17" monitor.

In the end Im guessing you want a wall size image of breathtaking image quality to impress all your friends. THIS IS ATTAINABLE using a 17" setup. Just dont give them a magnifying glass and ask them to inspect the clarity of the corners. Im a picky guy (to the point where 15" screen with its XGA res wasnt good enough) and I LOVE my 17" setup with standard triplet. I did use bigger fresnels however.

FOE you are my FRIEND.

I can't justify the WUXGA kit for a first PJ ($$$) but maybe for my second PJ I could.

Thanks so much for the replies everyone. Nov 1st is just around the corner!

Davide-NYC.