Home made Petzval or Celor Lens Questions

[Too Many Cameras]

I've had some fun making meniscus lenses for my 4X5 Super D and 35mm film cameras (I know, a bit of a different experience there.) I thought it would be fun to step it up a notch and make either a Petzval or Celor type lens. I'm having problems finding a resource that will help me understand what types of lenses to use -- focal length, lens shape, positive or negative, and so forth. Are there any good resources online that that can help provide lens design specs, or should I get an optical engineering book?

[Dan Fromm]

Look for the student version of the lens design program OSLO. It might handle as many surfaces as you'll have.

Unless you grind your own lens elements you're going to have no control over the glass used or the radii of off-the-shelf lens elements as can be bought cheaply from Surplus Shed or expensively from, e.g., Edmund Optics. I have no idea what you can do for a lens barrel.

In other words, have fun playing (play is good!) but you'll be lucky to end up with a decent lens.

[Nodda Duma]

You don't need OSLO for a Celor.

http://www.optics.ntut.edu.tw/ezfiles/93/1093/attach/29/pta_12521_6519049_02243.pdf

Get a pair of matching airspaced achromats and go to town.

[Too Many Cameras]

Nodda, the Celor definitely strikes me as easier, and it's probably the one I'll make first.



For the tube, ah, I have a genius plan -- step-up and step-down rings from eBay. 99 cents to $1.70 each, fixed width, and I can insert a couple pairs of narrow-diameter ones (like 77mm to 49mm and back) for light baffles. I've been housing meniscus lenses in rings so far and use a whatever-to-42mm to attach them to my M42 bellows. So I figured I would do that, slap a lens board at the end, and then use another one as a retaining ring. Janky? Yes. Easily undone and adjusted if the spacing is off? Also yes. This whole project is designed to teach me about how complex optics work and, with luck, give me a uniquely charactered lens as an end result. I'm definitely looking forward to having scads of fun with it.

[Nodda Duma]

I like the step ring idea to hold them. Ready-made retainers.


Let me know what lenses you select and I'll model them up

[Drew Bedo]

Barrel? Sometimes I see brass tubes and other parts for Petzval type lenses offered in online auctions. What about icing these parts to hold the glass elements?

[ruilourosa]

I have done a periscop type lens out of 2 achromat close up lens one leica and one minolta and i ended with a around 600mm f:/12 lens that delivers decent results (i was trying to make one ULF lens) but i might well go for a celor design or petzval as i ordered a air spaced achromat. I also used rings and step up filter rings to make the barrel.

Cheers


Rui Lourosa

[Too Many Cameras]

Nodda, I will for sure. I'm hoping I can figure out what I want to use soon.

Drew, In a perfect world, I would have two of my 300mm FL BCX f2.3 lenses to include, which would need a #10 coffee can as the housing. But, I only have one of those. So I'm going to have to save it for another project. :D

Rui, Nice! That's a good proof of concept for me. When I finish the whole deal, I'll post samples and sample images.

[Fr. Mark]

There's a book called Primitive Photography you might want to look at. Incl. section on lens/stop designs from loose elements. I think the most complex one is a cooke triplet.