18" EFL Opaque projector lens
I tried the Charles Beseler Company 18" E.F. Series III opaque projector lens in my 15" LCD projector. It gives me a fairly bright image (The lens is 5 inches in diameter!), but it does not perform as well as my process lens. In particular, I see some chromatic aberration toward the edges of the image. It also has a problem focussing a flat image on a flat screen, so I see either the center or the edges sharp, but not both at once.
Still, it is very nice for watching video, which is how I use my projector: Instead of a razor-sharp 65 lumen image, it gives me a less-perfect image with about 108 lumens on the screen. I can't see the defects in the image when I sit my normal 10 feet away. I need to get about three feet away to be able to see the unfocussed pixels.
I think it does have more FOV available, but as you go past 15" the edge performance will get worse. It would be terrific for a smaller format LCD.
I tried the Charles Beseler Company 18" E.F. Series III opaque projector lens in my 15" LCD projector. It gives me a fairly bright image (The lens is 5 inches in diameter!), but it does not perform as well as my process lens. In particular, I see some chromatic aberration toward the edges of the image. It also has a problem focussing a flat image on a flat screen, so I see either the center or the edges sharp, but not both at once.
Still, it is very nice for watching video, which is how I use my projector: Instead of a razor-sharp 65 lumen image, it gives me a less-perfect image with about 108 lumens on the screen. I can't see the defects in the image when I sit my normal 10 feet away. I need to get about three feet away to be able to see the unfocussed pixels.
I think it does have more FOV available, but as you go past 15" the edge performance will get worse. It would be terrific for a smaller format LCD.
yes, i agree with you, it is a great lens for small panels.
As i have always said, it is optimized for 24 full field of view angle (12+12) it is stated by the manufacturer specs. So do not try to check the cromatic corrections or barreling corrections... out of this FOV. (there are no corrections there) just inside the FOV.
I agree that the lens diameter heps on a brighter image since it collects more light.
Any pic for a comparison GG?
As i have always said, it is optimized for 24 full field of view angle (12+12) it is stated by the manufacturer specs. So do not try to check the cromatic corrections or barreling corrections... out of this FOV. (there are no corrections there) just inside the FOV.
I agree that the lens diameter heps on a brighter image since it collects more light.
Any pic for a comparison GG?
This is not the triplet sold by DIY
This is not the same triplet sold by DIYbuildergroup and DIYprojector company. It is a lens salvaged from an old opaque projector. It has a focal length of 457 mm (close to the DIY lens), but there is no reason to think it has the same performance. It is possible to make a triplet with these dimensions that is optimized for a much wider FOV.
I think this lens is probably optimized for projecting images from 8.5" by 11" paper, but that may mean they thought there would be a 0.5" margin on each side. So that would give you a very sharp image from a 12.5" LCD.
But this is not very important, unless you like to watch your projector screen from 3 feet away. From a normal viewing distance, this lens gives you a very good image from a 15" LCD with a 12 foot throw distance. At shorter throw distances it would be even better, since the longer LCD to lens distance would use less of the FOV.
This is not the same triplet sold by DIYbuildergroup and DIYprojector company. It is a lens salvaged from an old opaque projector. It has a focal length of 457 mm (close to the DIY lens), but there is no reason to think it has the same performance. It is possible to make a triplet with these dimensions that is optimized for a much wider FOV.
I think this lens is probably optimized for projecting images from 8.5" by 11" paper, but that may mean they thought there would be a 0.5" margin on each side. So that would give you a very sharp image from a 12.5" LCD.
But this is not very important, unless you like to watch your projector screen from 3 feet away. From a normal viewing distance, this lens gives you a very good image from a 15" LCD with a 12 foot throw distance. At shorter throw distances it would be even better, since the longer LCD to lens distance would use less of the FOV.
mm, i think it is very similar one though. Have any pics of the lens or pics o the projected images?
lens differences not visible in photo!
Two lenses could look exactly alike from the outside, and yet have very different performance. The glass each lens is made from, the radius of each curved surface, and the air (or oil) space between the lenses make all the difference, and you can't tell much about any of those from a photograph of the mounting tube!
But no, I don't have any photos right now.
Sorry
Two lenses could look exactly alike from the outside, and yet have very different performance. The glass each lens is made from, the radius of each curved surface, and the air (or oil) space between the lenses make all the difference, and you can't tell much about any of those from a photograph of the mounting tube!
But no, I don't have any photos right now.
Sorry
may be the same
Mine says "CHARLES Beseler COMPANY, EAST ORANGE, N.J U.S.A. 18" E.F. SERIES III" right on the front retainer ring in white letters. The mounting tube is 5 3/8" (136.525 mm) outside diameter, and 6 1/8" (155.575 mm) long.
If your lens is the same size and made by Beseler for an opaque projector, then it probably is the same. But there are lots of other lens manufacturers, who would have made different choices during their lens design.
Mine says "CHARLES Beseler COMPANY, EAST ORANGE, N.J U.S.A. 18" E.F. SERIES III" right on the front retainer ring in white letters. The mounting tube is 5 3/8" (136.525 mm) outside diameter, and 6 1/8" (155.575 mm) long.
If your lens is the same size and made by Beseler for an opaque projector, then it probably is the same. But there are lots of other lens manufacturers, who would have made different choices during their lens design.
there is Beseler and Beseler!
I have two 14" beseler lens from an opaque projector and the focal of the lens in the tripelt are not the same and there is a difference of 2mm in the diameter.
one is beseler from newark , NJ
the other is beseler from east orange, NJ
so may be two different factory for almost the same focal but with different settings
I have two 14" beseler lens from an opaque projector and the focal of the lens in the tripelt are not the same and there is a difference of 2mm in the diameter.
one is beseler from newark , NJ
the other is beseler from east orange, NJ
so may be two different factory for almost the same focal but with different settings
so we have those posibilityes by now:
AWI industries: 450mm focal lengh triplet (AWI project/part no.: E15080) with 136.5mm housing diameter.
left up is the lens at awi.
then
CHARLES Beseler COMPANY, EAST ORANGE, N.J U.S.A. 18" E.F. SERIES III"
as this one: http://cgi.ebay.es/ws/eBayISAPI.dll?ViewItem&item=7523118726&rd=1&sspagename=STRK:MEWA:IT&rd=1
Then there is that as well;
Projection optics company, east orange, NJ USA 18" E.F.
as this one;
And There are as well lenses with no writings on the front retaining ring but on the side where says "18" E.F.L" and a AO simbol (awi optics?)
Well, I believe the lens are very close from each other and neither of them has a stated field angle larger than 28 degrees (this is just looking to the barrel lengh, wider field angle needs closer lens so a thiner barrel necesarily) I think they are all different editions of the same lens, small changes but compatible with older versions, just my opinion.
Now just wonder, why the hell don´t we see a finished 15" projector with this "great" lens? (and I said 15" because if you go for 17", then you just are dreaming)
AWI industries: 450mm focal lengh triplet (AWI project/part no.: E15080) with 136.5mm housing diameter.
An externally hosted image should be here but it was not working when we last tested it.
left up is the lens at awi.
then
CHARLES Beseler COMPANY, EAST ORANGE, N.J U.S.A. 18" E.F. SERIES III"
as this one: http://cgi.ebay.es/ws/eBayISAPI.dll?ViewItem&item=7523118726&rd=1&sspagename=STRK:MEWA:IT&rd=1
Then there is that as well;
Projection optics company, east orange, NJ USA 18" E.F.
as this one;
And There are as well lenses with no writings on the front retaining ring but on the side where says "18" E.F.L" and a AO simbol (awi optics?)
Well, I believe the lens are very close from each other and neither of them has a stated field angle larger than 28 degrees (this is just looking to the barrel lengh, wider field angle needs closer lens so a thiner barrel necesarily) I think they are all different editions of the same lens, small changes but compatible with older versions, just my opinion.
Now just wonder, why the hell don´t we see a finished 15" projector with this "great" lens? (and I said 15" because if you go for 17", then you just are dreaming)
well you do not consider the 17"box from your friend in spain (diyletors) as a good settings with this triplet??
no, i didn´t consider his setup since his lens is not 450mm focal, not 18", not 24 degrees field angle.... As you know, his field angle is wider now, longer focal (500 mm) and thiner barrel (10cm).
his fov covers his 17", thats true, but the performances are worst, since the lens is not optimiced (optimiced= minimal aberrations). The fact is that he felt cheated by the triplet seller who said it would work perfect with 17", so he needed to solve that problem somehow after spending soo much money on it.
The seller still says it works with 17", that's really amazing.
his fov covers his 17", thats true, but the performances are worst, since the lens is not optimiced (optimiced= minimal aberrations). The fact is that he felt cheated by the triplet seller who said it would work perfect with 17", so he needed to solve that problem somehow after spending soo much money on it.
The seller still says it works with 17", that's really amazing.
AO lens
It's very likely an "AO" on a projection lens means it was made by American Optical. They were involved with just about every technical advance in cinema projection since the 1950s: wide-screen, cinerama, etc.
They used to have thousands of employees in Southbridge, Massachusetts but now do most of their manufacturing in Mexico. (Still "America", just not USA.)
It's very likely an "AO" on a projection lens means it was made by American Optical. They were involved with just about every technical advance in cinema projection since the 1950s: wide-screen, cinerama, etc.
They used to have thousands of employees in Southbridge, Massachusetts but now do most of their manufacturing in Mexico. (Still "America", just not USA.)
hello to truth fully say im a nooby here i have built a projector already and am ready for a new project i have just pict up a CHARLES Beseler COMPANY, EAST ORANGE, N.J U.S.A. 14" E.F. lense well i have the intire projector all the lenses r in good shape now will thise lenses work for a 15 lcd project
should i use all the lenses
the condensing lense is a monster
please some help in design would be appreciated i have posted some pics in another post in this section
ive been following your threads on focal distances and all of the math its pretty complex for me right now
should i use all the lenses
the condensing lense is a monster
please some help in design would be appreciated i have posted some pics in another post in this section
ive been following your threads on focal distances and all of the math its pretty complex for me right now
might be a bit difficult
The optimal field fresnel for that 14" fl lens would be 435 mm fl non-split or 395 mm fl split. Those will be harder to find than the more common 330 and 550 mm fresnels. Maybe you can find a 450 mm fresnel someplace.
The optimal field fresnel for that 14" fl lens would be 435 mm fl non-split or 395 mm fl split. Those will be harder to find than the more common 330 and 550 mm fresnels. Maybe you can find a 450 mm fresnel someplace.
You're assuming around a 97.8" throw I take it? You do have a little lee-way with those numbers depending on your throw (distance to the screen).
1 / (Projection lens focal length) = 1 / (LCD to Proj Lens distance) + 1 / (Throw)
An equation that Guy so kindly pointed me to a while ago. Then once you solve for "LCD to Proj Lens Distance", you add 20mm (approx) in an unsplit design to get the fresnel FL or subtract 20mm (approx) in a split design to get the fresnel FL.
well the only frensel i have i think is 508 mm its stamped 20 fl on it im gona used these un split so will this work for me i also have a large condenser lense with a fl of 114 mm i think all these lenses came from the same old ohp
508 mm fresnel
That should work fine for a non-split design. Too long is better than too short, for the field fresnel focal length: You can always use a large distance (ie. 80 mm) between the fresnels and the LCD, to make the arc image focus at the center of the projection lens. Or you can fiddle with the lamp to condensor fresnel distance to adjust the arc image focus location.
If you use a 220 mm fl or shorter condensor fresnel, then I don't think a pre-condensor lens will get you much more light. It is just a matter of geometry. The 15" diagonal fresnel already captures a lot of light. If you do get a pre-condensor lens to light the LCD evenly, you might actually lose more light in the lens than you gain. You will need a light meter to tell, because it is very difficult to judge relative brightness unless you see two images side by side.
That should work fine for a non-split design. Too long is better than too short, for the field fresnel focal length: You can always use a large distance (ie. 80 mm) between the fresnels and the LCD, to make the arc image focus at the center of the projection lens. Or you can fiddle with the lamp to condensor fresnel distance to adjust the arc image focus location.
If you use a 220 mm fl or shorter condensor fresnel, then I don't think a pre-condensor lens will get you much more light. It is just a matter of geometry. The 15" diagonal fresnel already captures a lot of light. If you do get a pre-condensor lens to light the LCD evenly, you might actually lose more light in the lens than you gain. You will need a light meter to tell, because it is very difficult to judge relative brightness unless you see two images side by side.
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