Homemade camera lens?

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?

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

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

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...

aerial telephoto lens

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?

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.

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:
Dead Link Removed

semeuse said:

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:
Dead Link Removed

Click to expand...

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

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!

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

I've been meaning to ask the same question from a slightly different angle. I somehow ended up on the mailing list for some optics houses (e.g. Edmund), which keep sending me catalogs of component lenses. What experiences have people had designing and building lenses from off-the-shelf components?

DBP said:

I've been meaning to ask the same question from a slightly different angle. I somehow ended up on the mailing list for some optics houses (e.g. Edmund), which keep sending me catalogs of component lenses. What experiences have people had designing and building lenses from off-the-shelf components?

Click to expand...

Anchor Optics is sort of a surplus division of Edmunds from what I can tell. All you really need to buy off the shelf is the elements since making the barrel is fairly simple. I suppose you could use a variable iris that Edmund or Anchor would have, but simple holes in a piece of black card stock works too. Definitely look at Alan Greene's book to get you started. His design is really simple, but you can use his ideas and make them more sophisticated too. I'm only working on my third lens so I am no expert and I've found it surprisingly easy.

Apparently anything more complex than a 2-element is asking for a headache, really a matter of luck and stopping down alot. Really unlikely that you would see any benefit (and perhaps would see worse) because things get far more critical (spacing, centration, etc). On the other hand, there there was a View Camera article on making lenses and the author (John Siskin?) DID make some admittedly soft (desired goal) 3-element ones.

So, single and 2-element projects should be fairly easy.

I use the lens areas of the Hyperphysics site (some school in Georgia, US) to help keep errors to a minimum.

But you are not going to be able to buy surplus elements and build a Tessar, Heliar, Planar, etc...in case that was your plan :O)

link to ariticle about making lenses

This will get you to the article about making lenses at my website. 3 Element lenses are not a problem if you can get negative optics. Also please check out this article on making cameras: www.siskinphoto.com/magazine4a.html. Thanks for mentioning my article. John Siskin

Also check your local library (770 section is Photography). You may be able to find a lot of excellent books on the subject. Your library may also be able to borrow from other libraries for stuff they dont have on hand. You can also buy a book as needed, but it's always better to check it out ahead of time, when you can. Look at SurplusShed.com for lenses, achromats, irises, etc. too. I hope this helps you.

Paul

Crude option 1:

Dollar store eyeglasses +1 (diopter) is 1 meter f.l.

A pair of the lenses concave to concave will give you a little more than 2 diopter and a little less than 500 mm f.l. (changes due to spacing of elements).

You'll need to fool around a bit to get them parallel. I would do that with no, or a large aperture, so you can see coma in particular. View a light bulb on some makeshift ground glass straight on, or project onto a white surface, wall, etc. That is the effect that looks like comet. Do the best you can to minimize that as it's probably the nastiest aberration (asuming you don't want it). Once that's minimized, put a smaller aperture ...hmmm, probably better to be in front of your pair of lens elements. You can meaure the f.l. approximately as the distance from the center of the lens pair to the wall/groundglass. At this point probably better to focus the outdoors so you're closer to viewing infinity.

Less Crude Option 2: If you can find a pair of close-up lenses, like a pair of +1's - they are already flat and easier to space close to parallel & centered.

Much less crude option 3: Surplus Shed (.com) has a 600 mm air spaced achromat in a barrel for US$11.50. Flat rate shipping is $5, so you may want to shop & buy some other treasure.

I bought one, took it apart, forgot what order they were in, (probably doesn't matter much), never tried it, put it away somewhere, and talked someone else into trying one (never heard from him either).

Maybe you can be the one to follow through.

Creative option #4, similar to something you mentioned eariler. I got a 15" process lens that doesn't fit easily into a shutter, so it's 'unworthy' in the serious ULF crowd. $15 or $20 IIRC on eBay. The rear cell WILL fit in an Ilex #3 (electronic) shutter. Because process lenses are frequently symmetrical, it's probably roughly a 30" f.l. lens that needs a small aperture. There are a number of lenses that aren't as desirable due to the impracticality of mounting in a 'legitimate' shutter.

Also, look up Andreas Feininger's work, maybe Eastman House Museum has his work. I believe he did some ULF using a magnifying glass.

Professor (first name forgotten) Wang in South Carolina (Sandy King knows him) has used or at least recommended the dollar store eyeglass method - that's who told me about it. He has better credentials than I.

Murray

Well, you can probably take tree amber and make yourself a lovely rustic lens. Also, I made a fixed-aperture ultrawide apo-keithagon for a few bucks using a pin and a copper sheet and I am pretty sure it will cover ULF. But as usual, the lens is not quite as apo as advertised.

Er, Keith, do you feel that you're aligned more with the school of f/64 than with the pictorialists?

For curiosity, how does the Gumagon (or is it a Saptar?) you described shoot?

Dan Fromm said:

Er, Keith, do you feel that you're aligned more with the school of f/64 than with the pictorialists??

Click to expand...

Alas, no school of photography has accepted me, and so I am consigned to somewhat less creative activities to fund my ventures.

Dan Fromm said:

For curiosity, how does the Gumagon (or is it a Saptar?) you described shoot?

Click to expand...

I tried to polish it before shooting through it and it shattered! But I think it really might work. Before I got distracted to other things, my thought was to make an apertured plate, then get the sap on there and keep it rotating until it dries. This should work better than the free-standing mess that I got on my first attempt.

Saptar, I like that.

Polymethylmethacrylate should also work nicely, and would have much better transparency than sap and fewer bubbles.

Wait a minute, this is St. Patrick's Day, not April Fool's. O Krap, missed St. Urho's Day yesterday. I'm embarrassed.

I heard about someone taking stream or pond ice, scraping it to an approximate double convex, melting it with hands to clear up the scraped areas, and using it to start a campfire. (Probably had bubbles like glass lenses of yesterday). Probably can't assume it would be a wide-angle lens, but the name Nerdagon comes to mind.

I wanted to use the name Mutagon or Mutar, but apparently one of them was a real commercial lens.

I like Ideotar, not a stupid lens, but one of found optics of unknown or forgotten origin.

I'm saving the name Hideotar, not for a Japanese designer, but for a really ugly one I haven't finished.

Joe's Crude Option #1: obtain an old 7x50 binocular; remove one set of objective lenses from said binocular, and, viola, you've got yourself a 50mm, 150mm focal length, f/3-ish doublet coated optics. Stopped down it makes nice images; wide open it has nice bokeh.

~Joe