Homemade camera lens?

[robopro]

This may sound a little off the wall, but I'm designing an 11 X 14 variable focal length pinhole camera that I'm thinking I may want to put a lens on some day, but I don't want to invest a lot of money in it, and my knowledge of optical imaging is pretty weak, I'm afraid. Anybody know of a good web site I could go to to see how somebody built their own large format camera lens?

[3Dfan]

No, but there is a book that discusses the matter called "Primative Photography."

[Jim Jones]

The Alternative and Adapted Process Forum at www.f295.0rg occasionally discusses this topic.

[robopro]

Jim, had a gander at the f295 site, and I changed my mind. If I ever decide to put a lens on my camera I'll just buy one. That was more information than I ever wanted to know! What the heck is a diopter? Never mind -- I don't really want to know...

[robopro]

I just read an article about a man building a 16X20 camera using the front half of a 30" aerial telephoto lens. I wonder how large in format a 24" lens would go? Saw one for sale at a local flea market but it's priced kinda high to just buy to find out... anybody have a guess?

[TheFlyingCamera]

rob-

a 24" lens SHOULD cover at least 11x14. It really varies dramatically on optical design. There are some out there that don't cover much more than 11x14- there are some that cover 20x24 with movement. I have a 600mm (24") Apo-Germinar that will cover 12x20 with mild movements. The 24" Apo-Artars may or may not cover 12x20. It also depends on your definition of coverage... to some folks, even illumination is sufficient; for others, it must be fully-detailed resolution equal to that on the optical center.

[semeuse]

Hey Rob -
Give building your own a go. I got an old Ansco 8x10 with no lens - figured I could pick up a lens cheap :rolleyes: After recovering from sticker shock, I decided to try to build one, following the basic instructions in Alan Greene's "Primitive Photography." If I can do it, anybody can. The first one worked so well, I decided to build a couple of more - just finished a 500mm Stenheil Periskop. Here's the first one - a simple 400mm landscape lens:

[Mark Fisher]

Hey Rob -
Give building your own a go. I got an old Ansco 8x10 with no lens - figured I could pick up a lens cheap :rolleyes: After recovering from sticker shock, I decided to try to build one, following the basic instructions in Alan Greene's "Primitive Photography." If I can do it, anybody can. The first one worked so well, I decided to build a couple of more - just finished a 500mm Stenheil Periskop. Here's the first one - a simple 400mm landscape lens:

I can second this. I made a symettrical lens and it was pretty darn easy. I just ordered some more lens elements from:

www.anchoroptics.com

If you don't want a fully featured lens (iris, shutter, ultimate sharpness), this works quite well.

Mark

[Ole]

I've been trying out various old lenses, and was surprised by how sharp pictures it's possible to get from a simple meniscus! With two menisci combined to a Periskop, it's pretty darned good!

I've tried my meniscus "Satz" - 15 to 75cm focal lengths in 10cm steps - both singly and combined, as well as a Voigtländer WZ 180mm symmetrical Periskop. At full aperture they're "pleasingly soft", stop down to f:32 and it's hard to tell the difference from e.g. an uncoated Protar!

[SteveH]

The center is very sharp, as Ole said. The lens consists of an achromatic meniscus, just placed into a barrel.