Mounting a lens from a folding camera onto a digital one


Link Posted 17/11/2021 - 19:57
I recently posted some results from mounting a Trioplan lens that was in a Pronto shutter mechanism onto a K1.

Here is a Schneider Radionar on a K5 as well as the Trioplan on the K1. Some members asked how I did it.

To start, you have to acquire your vintage shutter mechanism (which will have a lens embedded into it by default). They are normally found in vintage folding cameras and can be had cheaply right through to quite expensively (!) depending on what it is.

Whatever, if you open the back of the camera with the lens etc. folded up flat, you will be presented with the rear element of the lens and the threaded tube housing it. There will be a circular nut holding it in place. The nut is notched to facilitate its removal by the aid of a suitable two-pronged lens wrench. Undo it and the entire shutter assembly will be freed from the bellows and will probably fall into your hand when you pop the front open. (Watch you don't drop it!).

All you now need is some way of remounting it into a modern camera. I used an M42 camera body cap that screws into the front of (say) a Spotmatic or the M42 adapter ring you pop into a digital camera. The pictures will now speak for themselves ........

I mounted the body cap onto my lathe and made a hole in it to accept the rear tube of the mechanism - these are normally 25mm or 30mm diameter.

You could simply drill it out but it does need to be absolutely accurate and central.

Here is what you will be working with: the mechanism, the drilled out body cap and the circular nut - the paper washers you see on the rear of the
mechanism are often present and were added in the factory as shims to fine tune the focusing . Since you will be using live viewing (view finder or
rear screen) to focus these shims become a bit redundant but I keep them anyway.

Pretty obvious what comes next - you drop the body cap over the lens tube and screw the nut down tight to hold it in place, as it was originally.

A lens wrench really does come in handy for this since you risk scratching the glass if you use some ad hoc manner of turning the nut. The end
result is a compact unit that will screw straight into some extension tubes. You need some extension with a 105mm lens to achieve the correct
registration distance. 75mm can be put straight onto the camera (might be a bit too close - try it and see)

and a 50mm can only be used for close up work because you simply cannot get it sufficiently close to the sensor.
That said, you do get damn good close ups.

I put an M42 focusing helicoid in place of one of the extension tubes to make life easier and you can put an M42 adapter ring into the 10mm
tube from a set of K mount tubes. The M42 parts screw into this and it provides you with a very convenient K mount!

So, there you have it. The rest is up to you and your own ingenuity.
Both the *istDS and the K5 are incurably addicted to old glass

My page on Photocrowd - link


Link Posted 17/11/2021 - 20:04
Wow, that's a lot of work and a lot of thinking it through too. Could you please post some example images taken with these lenses on this thread?

Kind Regards

Nicola's Apartments, Kassiopi, Corfu

Some cameras, some lenses, some bits 'n' bobs


Link Posted 18/11/2021 - 00:38
David. If you go to 'Forum - Latest Topics' about 10th down the list presently you will find '1930s Meyer Trioplan mounted on a K1'. It has the first set of photos taken with this particular Trioplan and that prompted this topic. I've only just finished the 50mm Radionar and I only have a couple of pictures from it presently.

It isn't too happy with backlighting.

Much happier facing north

And happiest on bellows, where I think it will do rather well if this cheap ballpoint is any indication.

I will add some more trioplan maybe tomorrow.
Both the *istDS and the K5 are incurably addicted to old glass

My page on Photocrowd - link


Link Posted 18/11/2021 - 15:10
Taken by the combination shown at the top of this thread, the acers look wonderful, the sun was out and in the right place for some back lighting and rim lighting.
I am mightily impressed with this ancient lens.

All of these have the sun almost directly behind them. I had to do things the old-fashioned way with a bath towel over my head and the camera
so that I could see the live view screen while holding a large piece of corrugated cardboard above the lens to shade it.

A 125% crop from the original to capture the rim lights and money spider webs

A more reasonable crop (!) with rim lighting.

A Trioplan classic result. It makes the corresponding Radionar version (above) look very poor by comparison.
Personally, I like this a lot. You can see an enlarged version of this in the main gallery that shows it off much better.

Comments, criticisms and questions are welcomed.
Both the *istDS and the K5 are incurably addicted to old glass

My page on Photocrowd - link


Link Posted 18/11/2021 - 18:04
Incredible in every respect. Well done, davidwozhere.
Be well, stay safe.


Link Posted 19/11/2021 - 21:54
Excellent, thanks so much for describing the process. Looks like it was well worth the effort at adapting these vintage lenses.
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