Anyone try using LCD projector lenses for 4x5?

ericbrueg · Mar 7, 2007

I work at an A/V install company, and we allways have extra lenses laying about. The optics are pretty good and some are quite sizable. I am wondering if they would cover 4x5. Should I just make a custom lens board and try one? Has any one else tried this?

Jim Noel · Mar 7, 2007

Try it and let us know.

papagene · Mar 7, 2007

Where is Whiteymorange when you need him! On second thought... if the lens is from a LCD projector... way to new for Whitey!

gene

Dan Fromm · Mar 8, 2007

Diaphragm? Shutter?

nicolai · Mar 8, 2007

I bought one from Surplus Shed for this exact purpose but haven't tried it yet because the lens is truly massive. I'm still trying to figure out a way to mount it!

Iris-wise, I'm planning to treat it like a barrel lens: you can cut a slot for Waterhouse stops and make a set. I'm unlikely to do this as I like messed up lenses and will probably shoot it wide open.

To cope with the lack of a shutter, you can use a stack of ND filters to slow the shutter time down into the several second range, where it can be accurately timed with a lens cap. And there's always the famous (there was a url link here which no longer exists).

Whiteymorange · Mar 8, 2007

Did I hear my name??

WAY too new, Gene, way too new. I'm thinking of working with one that may have come from something like that but it's a low priority for me right now. Let it mellow for a few more decades.

Phillip P. Dimor · Mar 8, 2007

There is a Besseler 18" I think Projector lens that came off of a document-tracing device from the 50's. People turn these things into homemade lcd projectors with truly excellent results (130" tv for like $400 to $800 diy) The lenses are _real_ big.

Check out lumenlabs if you are interested. It's a neat hobby. And you get a better projector out of it than you could buy at circuit city if you are handy enough.

Kilgallb · Mar 8, 2007

I coordinate of LENS development for LCD and DLP projectors my company makes.

LCD projection lenses are telecentric. that is, all the light rays are designed to be in parallel because when you focus the image at infinity all the light rays are in parallel. They simply will not work as a taking lens. Also, the image circle is very small, typically 1-2 inches.

ericbrueg · Mar 8, 2007

Kilgallb said:
I coordinate of LENS development for LCD and DLP projectors my company makes.

LCD projection lenses are telecentric. that is, all the light rays are designed to be in parallel because when you focus the image at infinity all the light rays are in parallel. They simply will not work as a taking lens. Also, the image circle is very small, typically 1-2 inches.

I thought this would be the case. I noticed as I looked through most of them and got slightly off axis the light was immediately cropped on the opposite side. I found a 49 - 64mm with 2-3/4" diameter glass that seems like it could work with minimal movements. I think I'll go for it with a long exposure night shot to avoid having to figure out a shutter yet. I will post results.

Thank you everyone for the input.

epatsellis · Mar 10, 2007

Not with LCD, but CRT lenses, I can tell you that a Delta HD-6 (~6" dia, f1) makes a wonderful 4x5 astrograph as is, and with the field corrector removed and lens reversed covers 8x10 in a sort of "gall-esque" sort of way IIRC. An HD-10 (~8" dia., f1 and about 6#) with the front field corrector removed and mounted reversed looks to be about the right FL for a portrait lens. I'm in the middle of moving and once we dig out, I'll be cutting waterhouse stops for both of these lenses and I'll post some pics.

erie

ericbrueg · Mar 12, 2007

epatsellis said:
Not with LCD, but CRT lenses, I can tell you that a Delta HD-6 (~6" dia, f1) makes a wonderful 4x5 astrograph as is, and with the field corrector removed and lens reversed covers 8x10 in a sort of "gall-esque" sort of way IIRC. An HD-10 (~8" dia., f1 and about 6#) with the front field corrector removed and mounted reversed looks to be about the right FL for a portrait lens. I'm in the middle of moving and once we dig out, I'll be cutting waterhouse stops for both of these lenses and I'll post some pics.

erie

Thanks Erie, I did not even think of those old CRT jugs. I think we have a couple old Sony or Barco 3guns sitting back in the shop.

The LCD Lens I tried did not cover / converge correctly. I am thankful I only had to put about 20 minutes into a make shift lens board. I may consider disassembling the lcd lens, and see if there are any useful parts for making them into somthing else.

Anyone try using LCD projector lenses for 4x5?

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