home made Puyo-Pulligny lens

[Jan_6568]

Inspired by another thread here I am going to make a home made "replica" of Puyo-Pulligny The Adjustable Landscape Lens. I was looking for this lens for more then a year I could not find it.
I found some information on the web and in old books. Basically the lens is composed of two elements: plano-concave and plano-convex with identical focal length (10cm and -10 cm). The distance you set between the elements gives you desired focal length. My sources indicated that the lens had two diaphragms - front and rear. However, it does not say where the diaphragms should be placed. Also I have no idea why the lens needs two of them. I wonder, may be some of you, lens experts, could clarify that to me.

Regards,

Jan

[Ernest Purdum]

I can't tell you very much. All the Puligny-Puyo items are very uncommon. Only the designs were by the two named. Actual manufacture was by well known french makers.

The designers apparently liked the soft focus effects caused by the use of unachromatized lenses. Today, these would be hard to reproduce because of the color sensitivities of modern films, though I suppose it could be done after considerable experimentation with heavy filtration. Later soft focus designs usually aim for the desired results by use of spherical, rather than chromatic, aberration.

[Jan_6568]

According to one of my sources, Fotografika book by Jan Bulhak written in 1930thies this design used both chromatic and spherical aberrations to create soft focus effect. He gives few examples of images taken with this lens using panchromatic films (wonderfull!), my guess is that spectral sensitivity should be similar to modern films - please, correct me if I am wrong. What kind of filtration you mean? Would the aim be to mimic ortochromatic materials of the era?
BTW, I found and english translation of Puyo and Demachy book Sources of modern photography at CCP library catalog here in Tucson. It is very likely that the lens design is discussed in the book.


Jan

[Sven Schroder]

Hi

I was outbid on one, back in 04. The seller posted a colour polaroid made with it, of some peonies it was nice and soft with good colour (for what it is ). The rear iris was just behind the rear element to control the size of image circle (to stop bellows flare).
The lens had the other iris in the middle of the barrel as you would expect. Anyway I'll try and digout the original listing for more details, as I am working from memory here.

Hope this helps

Sven

[Jan_6568]

Anyway I'll try and digout the original listing for more details, as I am working from memory here.

Thank you, Steven - it helped a lot. I am going to mout the lens in Ilex #4 shutter so I think I can use the shutter's iris as a rear one, I will order a front iris only then. It would also be very helpful if I could see the lens on the original listing. Just courious - do you remember the price it was sold for? I saw one Puyo-Pulligny lens some few moths ago on e-bay live auction. It looked more like thier portrait design then Adjustable Landscape Lens but the seller knew nothing about the lens. It was sold for some $800, I guess.

regards,

Jan

[Sven Schroder]

Hi

I've found the post, saved when it was newly listed (so no sale price) I'll email the seller about using his pics, I must have found more info on the net, as the listing
does not contain all I remember.

Also a similar lens made by Dallmeyer "The Dallmeyer-Bergheim Soft focus Lens" from a 30's catalogue "This Lens composed of two simple lenses (the front positive and the back negative), the distance between which is variable, thus providing considerable latitude in focal length. The amount of spherical and cromatic abberation, due to the single uncorrected lenses, results in a certain amount of diffusion of focus, which produces the softness and delicacy aimed at by artistic workers."

Sven

[Jan_6568]

Hi Sven,
thank you very much, I really appreciate your help. To quote my favorite Hercules Poirot: "you have been most helpfull" . I am trying to design the barrel and one thing I am not sure about is where exactly to place the iris. I would tend to place it exactly in the same distance to both optical elements (not sure about that, this is my guess), but if the distance between the elements is to be variable then the iris should be mounted in a fixed distance to one of the elements and variable distance to the other one. Otherwise the barrel would be very complicated. May be you have an idea which element to choose?
At the moment I am not sure how to design barrel movements. I am thinking of two options: helicoid barrel, and the one in which you can unscrew optical elements and instert distance rings in between. The problem I see with helicoid design is that I would like to keep the rear element as close to the shutter leaves as possible but with helicoid barrel it is not so easy. I can have a machinist to make the metalwork for me quite cheap. What do you think?

kind regards,

Jan

[Ole Tjugen]

... The problem I see with helicoid design is that I would like to keep the rear element as close to the shutter leaves as possible but with helicoid barrel it is not so easy. ...

That at least is easy: Look at an old folding MF camera with front cell focussing. That's what you'll be making - a lens with the aperture just in front of the rear element, and where the front element moves on a helicoid.

[Jan_6568]

Ole, it sounds like a good idea, thank you.

Jan

[Paul Fitzgerald]

Jan,

Try http://www.surplusshed.com and search for B1016 and B1017. Might not be perfect but an easy and cheap start.

Good luck with it.