How to Mount a lens without retention ring?

[RussHerm]

I'm loving these old brass lenses, but only one of them came with the retention ring for mounting to a lens board!

I have used some gaffers tape and other unreliable temporary fixes - but what options are there for a better fix?

Thanks!

[mdarnton]

Most of my cameras have wood boards, which I make myself, from baltic birch plywood from the art store. For lenses without flanges, I cut the hole a bit small, then start filing the hole to a funnel shape, more open side towards the lens, until the threads start going in from that side. When I have a precise size to work with, I continue to straighten the sides of the hole without opening it, keeping it tight for the threads. It doesn't matter if the whole of the hole contacts the threads. I watch where the threads are cutting, and file a bit there to open the hole gradually, but keep it tight. A little candle wax on the hole makes the threads go in easily. Eventually I have a hole that's a secure, tight fit.

When I do this, I wait until the lens is fit before I decide which edge of the board is up or do the final planing of the board edges to size, and do the final fitting of the board to the camera so that the lens is "up" in the direction I want it to be.

I have some pretty heavy lenses hung this way, no problem. The reason I use plywood is because it's dimensionally stable with weather changes that would cause a solid wood hole to change size, and also because a plywood board isn't going to suddenly split and drop the lens.

I bought a lens once that someone had hot-melt glued into the board, and it took an hour to clean the mess off. . . as much as I could get off. Please, please, don't use glue or caulk, or something similar unless you plan to throw the lens in the trash when you're through with it.

[Greg]

Use a Hot Glue gun. Have never had a lens come loose from wooden or metal lens boards. Is 100% reversible... takes usually less than a minute to pull off the glue clean from the lens board and even lens threads.

[RussHerm]

wow - impressive craftsmanship! I may try that, but I'm thinking the probability of success (due to my lack of talent) is probably around 5%



I will also need to cut my lensboards to fit (from wood) for my 8x10 King camera (Rochester Camera Mfg co, ~1895) - but I don't have much of a woodworking shop at my disposal (let alone the skills). I have a skill saw and a dremel tool and a good drill with a coring bit... no work bench or rotor or table saw.... so I haven't really decided how I'm going to make the thin-lip around the board yet either...

thanks for the feedback - Maybe I'll find some local talent and see if I can entice them to give your technique a try...

[Michael E]

My experience with hot glue is good, it's easy to remove. I would never use other glue. Usually, I build my own wood boards and cut the hole tight enough to screw the lens in.

RussHerm, you don't need complicated tools. Have the plywood cut to size at the hardware store, cut the hole with a jigsaw. To build a lens board with a recess, glue two thin pieces together.

[mdarnton]

I wonder if this is an issue with different hot melt formulations, or perhaps clean threads vs slightly oily threads?

[rjbuzzclick]

I have a projection lens I mounted with large o-rings that fit snugly around the lens. One in front of the board and three behind it. The front of the lens was larger than the back so I only needed the one in front. Not permanent and easily removable.

[Alan Gales]

You could buy one of these. They show up on the forum and Ebay from time to time.

https://www.google.com/search?q=adjustable+iris+for+large+format+lenses+images&biw=1681&bih=962&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwi61Znso6bQAhVMHGMKHZvbBE4QsAQIIQ#imgrc=QVFtZfP54oU8SM%3A

[Jac@stafford.net]

You could buy one of these. They show up on the forum and Ebay from time to time.

https://www.google.com/search?q=adjustable+iris+for+large+format+lenses+images&biw=1681&bih=962&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwi61Znso6bQAhVMHGMKHZvbBE4QsAQIIQ#imgrc=QVFtZfP54oU8SM%3A

I use one of those and find it excellent.

This might be another solution for large lenses. (http://eksmaoptics.com/opto-mechanical-components/optical-mounts-830/self-centering-lens-optics-mounts-830-0027/) It grips the lens barrel by the outside, and alternately by the inside.

[Eric Woodbury]

I use an enlarging lens that doesn't have a ring. I took a metal lensboard and attached a plywood annulus. The inner diameter was basically the same as the outer diameter of the lens threads. Then I just threaded it in. I would never trust hot glue, as it can suddenly fail.

I wish there was a solution similar to my plywood ring but maybe a more compliant material such as Delrin or black Teflon or a plastic that softens with temperature. Put a hair drier on it until soft, thread in the lens and let it cool. Maybe PVC.

[Pere Casals]

I'm loving these old brass lenses, but only one of them came with the retention ring for mounting to a lens board!

I have used some gaffers tape and other unreliable temporary fixes - but what options are there for a better fix?

Thanks!


Presently I make my lens boards with a 3D printer, I just make the hole of the right size in order the barrel can get screwed in, ABS plastic allows for that...

This requires some Solidworks knowledge... I made CAMBO and Sinar boards, if you need those board types I can send you the STL file with the right hole size, then you can print it on your own in any 3D printer shop, or web based 3D print service... printing it may cost you some $10 to $20.

This is a board I made for a huge Lomo 600:

157392

[Jim Andrada]

I have a small iris clamp that's actually small enough to fit on a Technika lens board and that's what I use on my Technika. Only problem is that it's a very tight fit on the board and sits in the center rather than a few mm dropped, so it's like having a 1/4" of rise built in. Not a huge problem so far. One of these days I might get a small metalworking lathe so I can make my own adapters, retainers, etc.