new 550 fresnel is in my projector
I tried it first with a 220 mm fl condensor fresnel in an unsplit design. (Both fresnels together about 20 mm before the LCD.) The lamp arc to condensor fresnel distance is very close to 220 mm, so this should focus the arc image 550 mm from the field fresnel. And it does!
This puts the arc image right about at the first projection lens surface (18" opaque projector triplet). I can see that I need to make some adjustment to get the arc image a bit closer to the projection lens center: When I look back into the projection lens, I can see a very bright arc spot on a small part of the LCD. As I move my head from side to side, I see that spot move around on the LCD surface. When I get to the corners, I can see that most of the bright spot gets cut off by the front lens barrel edge. That tells me I need to move the arc image focal point a bit further into the lens.
Tomorrow I will try that, and also see how it does in a split configuration. Lux meter tests indicate that it is about 9% brighter than the identical configuration using my lumenlab "790" field fresnel. It looks like a very high quality lens, just looking through it, and it feels thicker and more rigid than the lumenlab fresnels.
If you order one, you may want to select the normal air shipping, instead of the special air shipping. I got mine from R.O.C in just a few days using the normal air shipping.
I tried it first with a 220 mm fl condensor fresnel in an unsplit design. (Both fresnels together about 20 mm before the LCD.) The lamp arc to condensor fresnel distance is very close to 220 mm, so this should focus the arc image 550 mm from the field fresnel. And it does!
This puts the arc image right about at the first projection lens surface (18" opaque projector triplet). I can see that I need to make some adjustment to get the arc image a bit closer to the projection lens center: When I look back into the projection lens, I can see a very bright arc spot on a small part of the LCD. As I move my head from side to side, I see that spot move around on the LCD surface. When I get to the corners, I can see that most of the bright spot gets cut off by the front lens barrel edge. That tells me I need to move the arc image focal point a bit further into the lens.
Tomorrow I will try that, and also see how it does in a split configuration. Lux meter tests indicate that it is about 9% brighter than the identical configuration using my lumenlab "790" field fresnel. It looks like a very high quality lens, just looking through it, and it feels thicker and more rigid than the lumenlab fresnels.
If you order one, you may want to select the normal air shipping, instead of the special air shipping. I got mine from R.O.C in just a few days using the normal air shipping.
thanks for the input GG.
what about the focus on the corners? can you tell me more info on your setup, trhow, lcd size...
thanks.
what about the focus on the corners? can you tell me more info on your setup, trhow, lcd size...
thanks.
Sounds good so far Guy. Mine haven't arrived yet, but I think I chose the normal air. (whatever the $17 option was.) Can't wait though. 😀
The 3dlens 550mm FL fresnel has 0.2 groove pitch. The 220FL fresnel on LL and DPC are 0.5 are they not? So I thought this was a no no. As in no good. Guy Grotke where did you get your 220 FL fresnel and what size is it exactly?
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Rox: This is just an opaque projector lens, not one of the higher-priced DIY projection triplets. I can see the individual pixels from center to edge, but the screendoor lines are not as black as with my $$$ process lens. I can see the RGB subpixels at either center or edge, but not both at once.
15" XGA LCD, unsplit design, 250 Watt Ushio retrofit lamp, silver-plated spherical reflector, 18" EFL 5" wide opaque projector lens, 12 foot throw to a high gain screen painted on the wall.
dracul: My 220 is a standard lumenlab 0.5 mm pitch fresnel. The finer-pitched 550 works great with the grooves right up against each other. When I used the lumenlab 790 mm field fresnel, I had to align the two fresnels very carefully not to get interference patterns. With the 550 it works fine, no matter how it is aligned. I never see any interference patterns on the screen.
Rox: This is just an opaque projector lens, not one of the higher-priced DIY projection triplets. I can see the individual pixels from center to edge, but the screendoor lines are not as black as with my $$$ process lens. I can see the RGB subpixels at either center or edge, but not both at once.
15" XGA LCD, unsplit design, 250 Watt Ushio retrofit lamp, silver-plated spherical reflector, 18" EFL 5" wide opaque projector lens, 12 foot throw to a high gain screen painted on the wall.
dracul: My 220 is a standard lumenlab 0.5 mm pitch fresnel. The finer-pitched 550 works great with the grooves right up against each other. When I used the lumenlab 790 mm field fresnel, I had to align the two fresnels very carefully not to get interference patterns. With the 550 it works fine, no matter how it is aligned. I never see any interference patterns on the screen.
Mine just arrived!! 😀 I like the $5.9 total price on the customs sheet 😉
After about 15 min of unpacking 😀 I noticed that the corner on the 550 fresnel is broken though, which is sort of disappointing. It's pretty small though, so I don't think it will be a problem.
I'll see what I can do tonight and try to get some pictures up on my site later tomorrow.
After about 15 min of unpacking 😀 I noticed that the corner on the 550 fresnel is broken though, which is sort of disappointing. It's pretty small though, so I don't think it will be a problem.
I'll see what I can do tonight and try to get some pictures up on my site later tomorrow.
My 550 fresnel just arrived too. It also had a corner removed from it. 😕 I think I can still use it.
I sure wish I had more time to work on this project....
I sure wish I had more time to work on this project....
any new on the 550 fresnells/135 triplet/15"-17" ?
did it improve anything?
(the only input I have by now is from GG, who said it improved the brightness by 9% on his 15" setup comparing to the 780mm field).
any other input?
did it improve anything?
(the only input I have by now is from GG, who said it improved the brightness by 9% on his 15" setup comparing to the 780mm field).
any other input?
Got the 550mm the other day. Fast!!! Excellent quality. Thanks 3D.
Made a coffin box.
Stripped my 17" LG1710B, and mounted all the bits today.
Fired it up with a 400W double ended Osram 6500K MH bulb.
lamp-IR glass-330mm Fresnel-LCD-550mm fresnel-pro lens
135mm from DIY has a great image in the middle- the screen door is highly visible on a 12 foot diagonal (in the centre) and on high res photos looks fantastic.
But as Rox and so many others have pointed out, the 135mm lens does not have corner to corner focus. FOV is too small for 17". Might be able to get away with 13" 4:3 if lucky enough to have one.
The light is even right up to the corners with the 550mm lens but if you focus for the edges, the middle is not focussed. 😕
We pulled apart another 135mm and reduced the spacing between the lenses by 20mm, replacing the plastic rings with hand cut MDF rings. It increased the focal length, but again- no corner to corner focus. If anything it looked a lot worse.
I'm projecting onto a slightly yellowed wall, so brightness is a bit dissapointing. On normal DVD res, the image is awesome in the centre. But no way to get 1280 x 1024 with this lens for use with text.
Anyone had some luck with this kind of setup? Any tips on making it a bit brighter? I'm a very very very green at this PJ thing.
Made a coffin box.
Stripped my 17" LG1710B, and mounted all the bits today.
Fired it up with a 400W double ended Osram 6500K MH bulb.
lamp-IR glass-330mm Fresnel-LCD-550mm fresnel-pro lens
135mm from DIY has a great image in the middle- the screen door is highly visible on a 12 foot diagonal (in the centre) and on high res photos looks fantastic.
But as Rox and so many others have pointed out, the 135mm lens does not have corner to corner focus. FOV is too small for 17". Might be able to get away with 13" 4:3 if lucky enough to have one.
The light is even right up to the corners with the 550mm lens but if you focus for the edges, the middle is not focussed. 😕
We pulled apart another 135mm and reduced the spacing between the lenses by 20mm, replacing the plastic rings with hand cut MDF rings. It increased the focal length, but again- no corner to corner focus. If anything it looked a lot worse.
I'm projecting onto a slightly yellowed wall, so brightness is a bit dissapointing. On normal DVD res, the image is awesome in the centre. But no way to get 1280 x 1024 with this lens for use with text.
Anyone had some luck with this kind of setup? Any tips on making it a bit brighter? I'm a very very very green at this PJ thing.
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small suggestion
If you can drop the throw distance, then the lens will be farther from the LCD. That should give you more pixels in focus because it will not try to use such an extreme FOV. It will also make your screen image much brighter. If you cut the image size in half, it gets four times brighter.
If you want to see a perfect screen image, you can look for a process lens. Something like a Rodenstock 480 mm fl APO Ronar. It will give you perfectly focussed subpixels from center to corner, but you will have to get those fresnels just right to get much light into it. I think it is only about 65 mm diameter.
Lumenlab has a new 500 mm fl 100 mm diameter triplet coming soon. It will be expensive, but I think it will give you a much better image, even with a 17" LCD.
If you can drop the throw distance, then the lens will be farther from the LCD. That should give you more pixels in focus because it will not try to use such an extreme FOV. It will also make your screen image much brighter. If you cut the image size in half, it gets four times brighter.
If you want to see a perfect screen image, you can look for a process lens. Something like a Rodenstock 480 mm fl APO Ronar. It will give you perfectly focussed subpixels from center to corner, but you will have to get those fresnels just right to get much light into it. I think it is only about 65 mm diameter.
Lumenlab has a new 500 mm fl 100 mm diameter triplet coming soon. It will be expensive, but I think it will give you a much better image, even with a 17" LCD.
awesome. Thanks Guy.
I'm going to do this as soon as I get spousal facility approval to move some furniture.
Negotiations are in progress...
I'll post some results as soon as its done.
I'm going to do this as soon as I get spousal facility approval to move some furniture.
Negotiations are in progress...I'll post some results as soon as its done.
I moved things closer to the wall and tightened up all the lenses etc. I'm still trying to find some kind of driver to do horizontal mirroring. Any tips?
This is 1280 x 1027, showing the centre right hand side. Focus is OK in the centre, even at the sides.
Light in the corners is still not optimal, but a pre-condenser and better lamp placement might help.
This is 1280 x 1027, showing the centre right hand side. Focus is OK in the centre, even at the sides.
Light in the corners is still not optimal, but a pre-condenser and better lamp placement might help.
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