GXR M Mount, adapter and vintage SLR lenses

[Tom Caldwell]

Rohan,

Glad to see you experimenting with larger size lenses. I have found this productive myself. The GXR works very well with RF lenses but there is no reason whynit cannot handle quite large lenses.

The largest I have seriously used on the GXR has been a Canon FD 200mm f2.8. For a lens of this capability it is not over large or over heavy.

Tom

 

[RDM]

A quick bit of CAD modelling, some 3D printing and now the Agfa lenses fit on the GXR.




Unfortunately image quality with the lenses is pretty bad. Not sure what's going on as I'm inexperienced in the world of vintage lenses. Fog (although they seem pretty clear just looking at them)? Do I need to paint the inside of the adapter matt black (the plastic isn't really that translucent)?

35mm


50mm


90mm


Cheers

Rohan

 

[Tom Caldwell]

Looks like a pretty neat job Rohan. Maybe if you turned the EV down a little?

Tom

 

[RDM]

Thanks Tom.

Yep. It needs to be painted. I just wrapped my hand around the adapter to cover it and took a couple more shots - huge difference. The adapter is simply too translucent. I will give it a coat of matt black internally and shoot some more with it.

Cheers

Rohan

 

[RDM]

All painted now and that has fixed the "faded look" present in the initial images. Will be fun to test these old rangefinder lenses out. They look to be promising.


Beige on beige on beige

 

[RDM]

A couple of recent shots using the Agfa 35mm lens.

 

[Blow-in]

Great results! The lenses look really good too on your M module.

Richard

 

[Tom Caldwell]

Rohan, you have done a great job with those adpapters. An inspiration to us all.

Tom

 

[RDM]

Thanks for the kind words Tom and Richard.

The help and advice on offer on this forum has been great and has fired my interest in photography again.

The Agfas seem to be working well. They have less contrast than more modern multicoated lenses but I personally can't fault their sharpness.

Hopefully with their single coating they may prove to be excellent for black and white - that is if you believe what you read on the internet on this subject.

I only wish they made a wider lens than the 35mm.

I think I'm going to "bite the bullet" and get some aluminium adapters made up to replace the plastic one I've built. Just wanted to wait and make sure the lenses were worth it.

Cheers

Rohan

 

[Tom Caldwell]

Rohan,

Just curious as to how you made the adapter. The process of 3D printing is known to me (but not presently used) and I understand that some knowledge of CAD is necessary to make the object. That said I can see how you have ingeniously usd a LM adapter as a host for your "made" adapter extension. Obviously thinking on your feet.

How do you fit the extension on to the Agfa lens? Is it merely screw attached or is there some other way that the lens is attached to the lens end by your extension that replicates an Agfa female mount.

I am curious for two reasons. Firstly that an Agfa Silette was my very first camera back in the 1960's. It must be a different model becasue as far as I know the lens was a fixed attachment. But I have no intention of trying to collect Agfa lenses and do not need this adapter mount.

The curiosity is from a fellow "adapter manufacturer" who has managed to figure out the maths and successfully manufacture a M42 conversion for the Meyer Telefogar lens in Altix mount. The process needs a metal lathe and some greater skills than I usually possess to drive it. But I do have a small metal lathe and managed to get my M42 conversion - including infinity focus. In this case it is a simple replacement of one adapter end with another. I have not perfected it. The M42 screw thread is force-fit and stays rigidly in place but can be popped off if the lens is over tightened. I have to make a mechanical fixing and this will probably need a couple of tiny screws which I think I might have to make. I am reluctant to use glue as the M42 threads would have to come off if the lens itself was ever in need of accessing.

Right now it is a 90% complete work in progress and is a neat job - I have to be careful that a rush to complete the last 10% spoils the professionalism.

Tom

 

[RDM]

Hi Tom.

I modelled the adapter myself in CAD - after measuring the flange to focal plane distance off the Agfa Ambi Silette camera which came with the lenses and doing the simple sums to match it the M Mount flange to focal plane distance. Then had it "printed" at my workplace and attached a Leica lens flange which I bought off eBay using the appropriate sized screws.

The Agfa Ambi Silette is an interchangeable lens version of the earlier Agfa Silette I believe.

The original Agfa mount itself is a clever piece of engineering which was going to be too complex for me to replicate accurately - so I didn't try. Its basically 3 small tabs which rotate into a groove in the inner lens barrel to capture and hold the lens in place. I waited for a while to see if a non working or scrap-able Agfa Ambi Silette came up for sale anywhere so that I could pilfer the crucial working parts to replicate it exactly but had no luck. I settled on 3 hex key grub screws instead which just screw down through the adapter into the same groove in the inner lens barrel which the aforementioned tabs locate into.

it's certainly not a "quick change" system but does the job securely enough.

The aluminium ones wll be CNC machined using the same CAD model.

I would be happy to share the CAD model/design with anyone who wanted it.

Hope that makes some sort of sense.

Cheers

Rohan

 

[Tom Caldwell]

Hi Tom.

I modelled the adapter myself in CAD - after measuring the flange to focal plane distance off the Agfa Ambi Silette camera which came with the lenses and doing the simple sums to match it the M Mount flange to focal plane distance. Then had it "printed" at my workplace and attached a Leica lens flange which I bought off eBay using the appropriate sized screws.

The Agfa Ambi Silette is an interchangeable lens version of the earlier Agfa Silette I believe.

The original Agfa mount itself is a clever piece of engineering which was going to be too complex for me to replicate accurately - so I didn't try. Its basically 3 small tabs which rotate into a groove in the inner lens barrel to capture and hold the lens in place. I waited for a while to see if a non working or scrap-able Agfa Ambi Silette came up for sale anywhere so that I could pilfer the crucial working parts to replicate it exactly but had no luck. I settled on 3 hex key grub screws instead which just screw down through the adapter into the same groove in the inner lens barrel which the aforementioned tabs locate into.

it's certainly not a "quick change" system but does the job securely enough.

The aluminium ones wll be CNC machined using the same CAD model.

I would be happy to share the CAD model/design with anyone who wanted it.

Hope that makes some sort of sense.

Cheers

Rohan

Rohan

I am an accountant and not used to CAD but I did play around with one of the early DOS based light-CAD programs for the basic idea quite a few years ago and I did a year of "Technical Drawing" at school. But that hardly qualifies me as CAD-aware. But I am interested in 3D printing for its possibilities and have downloaded a couple of "free" CAD programs to see if I can get my head around them. It might take me a little while to do so - especially with all my other interests. I think I could get a grip on it after a suitable amount of hair-tearing - all those hard learned manual drawing methods so hard learned at school now renedered not necessary by the wonders of computer technology!

I was interested becasue I could see that your screw on flange would work well and the rest of the adapter would be a fairly simple tube but the camera end mount (which I do not know) would be a more complex thing indeed. I relate to the Altix mount which is a simple breech lock but a heavy engineering exercise to replicate. I have bought a couple of old Altix cameras to see if I could "pirate" their mount but it adds all sorts of dimensional difficulties that I just don't wish to know about and of course you can only have as many "adapters" as you can get Altix host bodies.

Luckily the Altix flange focal length is almost identical to M42/PK. In fact I managed to calculate that the mating flange itself is slightly different to the measured distance which seems to be the centre of the Altix locking tabs. It then becomes exactly the same as M42 which leads me to think that the Altix mount was a simple conversion of the M42 dimensions to a breech lock bayonet type intended perhaps to rival the plug twist and lock K mount. But it is quite hard to change the mount to M42 because the dimensions are in fact so tight.

My process is irreversable but of course Altix mount lenses are only really useful on Altix mounts otherwise. Much the same with Agfa lenses.

My Silette would be circa 1960 when bought new and most likely made late 1950's. Pretty basic - straight fixed optical viewfinder - limited shutter speed - fixed lens - no light meter. I did manage just a few keepers and quite a few early teens type images of things that might be worth photographing at the time. But lack of funds to buy and develop film made sure that my talents remained quite hidden. How different photography became in the digital age - it is now all so easy. Now we find and recycle old lenses so that we can suffer some "photographer's pain".

Tom

 

[RDM]

Hi Tom.

If you need anything 3D CAD modelled for your project just send me a sketch with enough views and dimensions on it and I'll sort it out.

I can then give you a file that you can send to one of the 3D printing companies (there are many online) and have your parts made out of a structual plastic like nylon. Alternatively you can send them to a CNC mill company which will be able to cut them out of steel or aluminium for you.

Cheers

Rohan

 

[Tom Caldwell]

Thanks Rohan, I will bear that in mind, I am of the inventive type of mind.

I have just made myself a "Long Tom" which is a device after the Clearviewer type made up out of scratch components - the only trouble is that the distance from the lcd to the lens varies acording to the lens in use and the sweet focus spot on my version is actually 5 1/4" or 350mm from the lcd screen and of course my version does not fold which makes it quite cumbersometo use. But it dos work well. If I could find a correct magnification lens I am sure that I could make a "Short Tom" as well.

The essence of this device is as mch that it requires the slr type grip with eye to the lens. This makes for a much better stance and grip with the camera held like an slr. Even if it might look "odd" it is practical.

I have a half assembled 3D printer kit but when it came to the electronics side it stalled as I want to do it correctly then a few family matters interfered. Just as soon as I can I will get back to it. I see 3D printing as a huge area that will be developed exponentially once it takes root. The bureaus will get all the metal printing jobs forever as this is well beyond the small home applications.

Tom

 

[RDM]

Finally got some adapters built in aluminium.



Here's a few recent shots as well.

Seascape shot with 35mm Agfa lens.


Macro using reverse ring on 50mm Pentax lens.


Melbourne White Night Festival shot with 24mm Pentax lens.

 

[Tom Caldwell]

Congratulations Rohan, it looks like you have cornered the adapter business - Agfa-LM

Tom

 

[RDM]

Thanks Tom.

Sales forecasts are high - at least that's what I told the shareholders.

Cheers

Rohan

 

[Tom Caldwell]

One off would be a lot of work, someone best place an order for 500 to make it worth running the lathe :?

Tom

 

[RDM]

Have just gotten back from holidays where I used only the Nikkor IX 20-60mm lens shown earlier in this thread. I also tried playing with some of the JPEG image settings - B&W(TE), Vivid and Toy Camera. For anyone who is interested here are some of the results.

 

[Tom Caldwell]

I think one of the objects of travel photography is to capture the atmosphere of the place visited. You have done well here.

Tom