Hi guys, I've been researching this, and haven't found much of an answer: for a 15" lcd, which lens is better, LL's or DIYPC's 320mm focal length projection lens? Will both do a fine job with a 15" lcd? Also, I previously thought that these 320mm focal length lenses wouldn't get nearly sharp and bright enough corners with a 17" panel, but recently I've read a few posts that give me the feeling that it's not corner sharpness and brightness that is the problem, but that people do not like the short throw distance. Could these lenses work with a 17" panel?(or have they been reported to?). Thanks all for your help.
P.S. I would quickly go out and buy lumenlab's pro lens, except for the fact that it's $200: no way I'm spending that much.
P.S. I would quickly go out and buy lumenlab's pro lens, except for the fact that it's $200: no way I'm spending that much.
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As a side-note, does an 18" beseler work well? I believe a couple of guys have/had them, but many people seem to have moved on to 21" opaque lenses. Would an 18" beseler work with a 17" screen.
once again, thanks for your help guys.
As a side-note, does an 18" beseler work well? I believe a couple of guys have/had them, but many people seem to have moved on to 21" opaque lenses. Would an 18" beseler work with a 17" screen.
once again, thanks for your help guys.
Hm, thanks, v1d9uy. Still not quite sure what I'm gonna do, between getting a 80mm standard, 18" beseler, or going all out for a 21".
Although it appears that the 22 inch Beseler lens will work with a 17 inch LCD, there have been no posted results confirming this.v1d9uy said:
hey it should work with the 17" monitor but the corners will be a little blurred. to avoid this you could just use it in widescreen format. and make sure u use a 550mm front fresnel
Well, I would say it can go both ways. Not having either, I have just heard from others. Here is what the opinions are from hearsay. The lumenlab gives corner to corner focus. It is roughly 100mm. The Diycompany is almost corner to corner, seen pics that give maybe a 3 inch or so from the corners unfocused, and has a 135mm that will accomodated larger arc lights. Also, the guy at diyproj is working on getting a 500mm focal length that will help give corner to corner focus on larger lcd's. I will know soon, because I have a 135mm ordered, it was much cheaper. I will post results.
Hello
Please post results as this is probably what I will have to go for.
I can't seem to find something decent for my requirements.
Please post results as this is probably what I will have to go for.
I can't seem to find something decent for my requirements.
Fizzer said:
Results with a 17 inch lcd and a 18" F.L. Beseler lens are here.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=69975&perpage=10&pagenumber=1
Hi guys:
being that I wasn't going to fork out $130 for an iffy lens on the compatible front, or $200 for a perfect lens, as well as $40 on a new fresnel, and continually got sniped out of my eBay auctions for nice opaque projector lenses, I decided to try out lumenlab's standard lens (some had said, and more had hinted, that the lens worked well enough with a 17", except for slightly, but acceptably, darker and out of focus corners, as well as a larger projection). I received the lens on monday, a week after I had ordered it, and tested it Tuesday, simply with my Dell 1702fp's "no signal"/color bar menu, which bounces around from side to side. I know that this isn't the best test to test for nice focus and brightness, but I'll tell you my results anyway: when I had the center area in more-or-less correct focus (being able to see the screen-door), the farthest edges of the image still had a slight trace of the screen door, and were acceptable focus-wise. I could not, however, fairly measure brightness, due to the crudeness of the test. Also, there seemed to be a bit of chromatic abbhoration in the extremeties of the image, but I'm not quite sure if this was my imagination or not, and if it was not, then it could very well be due to the fact that the lens was resting in a whole made for a larger lens, and thus was slightly lower than it should have been.
While all that is a good sign, it's a good sign from a very provisional test, so take it with a big grain of salt. In other words, don't ditch your efforts to get a cheap opaque pj lens in order to get a standard ll one just because of this. While I may be too busy, I'm hoping that I'll be able to get the lens even more properly mounted this weekend, as well as to get an input source plugged in (probably my good old testing source, my computer) to test more precisely and truly for corner focus and brightness. I'll probably post my results in a new thread, as as I near the completion of my projector, and gain more free time in general, I'll add details and pictures about my projector.
being that I wasn't going to fork out $130 for an iffy lens on the compatible front, or $200 for a perfect lens, as well as $40 on a new fresnel, and continually got sniped out of my eBay auctions for nice opaque projector lenses, I decided to try out lumenlab's standard lens (some had said, and more had hinted, that the lens worked well enough with a 17", except for slightly, but acceptably, darker and out of focus corners, as well as a larger projection). I received the lens on monday, a week after I had ordered it, and tested it Tuesday, simply with my Dell 1702fp's "no signal"/color bar menu, which bounces around from side to side. I know that this isn't the best test to test for nice focus and brightness, but I'll tell you my results anyway: when I had the center area in more-or-less correct focus (being able to see the screen-door), the farthest edges of the image still had a slight trace of the screen door, and were acceptable focus-wise. I could not, however, fairly measure brightness, due to the crudeness of the test. Also, there seemed to be a bit of chromatic abbhoration in the extremeties of the image, but I'm not quite sure if this was my imagination or not, and if it was not, then it could very well be due to the fact that the lens was resting in a whole made for a larger lens, and thus was slightly lower than it should have been.
While all that is a good sign, it's a good sign from a very provisional test, so take it with a big grain of salt. In other words, don't ditch your efforts to get a cheap opaque pj lens in order to get a standard ll one just because of this. While I may be too busy, I'm hoping that I'll be able to get the lens even more properly mounted this weekend, as well as to get an input source plugged in (probably my good old testing source, my computer) to test more precisely and truly for corner focus and brightness. I'll probably post my results in a new thread, as as I near the completion of my projector, and gain more free time in general, I'll add details and pictures about my projector.
Miedosoracing said:
The 135mm lens at diypj CANT focus screens larger than 15" no matter what fresnel you use. Its FOV is too small so it can't work on larger screens without modding it and bringing the three glass closer elements together.
Like I had stated, it is being worked on right now to have a 500mm EFL so that will then be possible. that is all the info I have.
Miedosoracing said:
I was under the impresion he was trying to get a 500mm efl fresnel to match the triplet. I've tried that triplet with several different fresnel combinations and even modded it (with not alot of success) and in its unmodified state it really does struggle with even a 15" LCD. Have you a link to the thread that alan S was talking about that, I'd love to have a read.
Cheers
No info on this yet. i am actually working on it with him. The lens company will recut one or two of the lenses it sounds like, to change the fl. It will not just be a move of the lenses. We have to come up with the right combo to give to them first. I will keep you up to date. A lens design company is giving me hints on what to use. then we have to try them. I will keep you updated, I have some of their lenses ordered to try in the 135mm, so just waiting for them, then Alan will test them and go from there.
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