Hacked-into-Leica-mount lenses

[jarski]

Originally Posted by raid

Jarno: I have the same lens and I would like to hack it into LTM. How did you do it?

hi Raid. I bought it like that from leicashop.com year or two ago, with plan to use it one day with M9. dont know exactly how it was made

I havent seen it for a while as I've been traveling, but IIRC looks like combination of Tenax lens optics part and some (FSU?) Elmar-copy LTM part. there is focus knob, but no infinity lock.

maybe Brian could give better educated guess what kind of dremeling would it take to convert yours ?

[varjag]

Konica WaiWai 17mm, a.k.a. Redneck Hologon:

[Brian Sweeney]

On the 40mm lens: is it RF coupled? that would require an "indexed cam", but to provide coupling through the focus range.

17mm- cool!

[buzzardkid]

Brian, I think it is RF coupled, since it's on an Industar mount. Maybe the focus does shift, since it's a 40mm lens on a 50mm helicoid.

My Perfex Wollensak 50mm 2.8 is perfectly coupled, I tested it on the M8 when I still had it until it was perfect. The sole reason I miss that M8 for, lens hacking & focal plane testing was a lot easier back then...

[Brian Sweeney]

My M8 is used for all of my tests. I keep a 1.25x magnifier on it.

The M9 is also handy for testing Jupiters...

[archive59]

I am surprised to have this lens as I spotted it on Ebay and put in a speculative bid at what I thought was a low start price and got it. Either I am not as smart as I would like to think or I got lucky.
The Schneider Retina-Xenon f2.8 5cm is clear, the Compur Rapid shutter works and the Summar back-end is rangefinder-coupled. No idea if that is accurate but it all seems very well engineered.
Why would this have been done? And more importantly how do I use it!? Do I use the camera or lens shutter?

[Brian Sweeney]

I've done that for a Nikon RF.... Hacked a 50mm lens with shutter into a mount for the Nikon. When I want to use the focal plane shutter, I set the shutter on the lens to "T". Using the lens-shutter, set the camera to "T".

The Compur shutter flash-syncs at all speeds. Leave the focal plane Shutter Open, using "T" or "B", and fire the Compur shutter to sync the flash.

Oh, and COOL LENS!

[archive59]

Cheers Brian. I will be interested to see what results I get with this lens. Unfortunately I don't have a digital camera I can mount it on.

You're right it is a pretty cool lens.

Thanks,

Mark

[archive59]

A couple more pictures of the Schneider/Compur Rapid. Am I correct in thinking that the flash sync connector is an ASA bi-post connector? And would that also have been added when this lens was hacked?

[john neal]

Well, I have succumbed to the itch, and bought another Ziess lens to hack into a J8 mount for LTM.

I'm told this is late 1940s, but don't know exactly which year - it looks in nice condition, well the glass anyway. I probably paid too much for it, but it was less than a 1937 uncoated collapsible version on the great auction site (I already have one of those in LTM, so I'm pleased enough. It has to travel from stateside, so I won't see it for at least a week.

Any dating info would be most welcome.

I'm looking forward to getting this on my M3....

[dexdog]

John, your lens was part of a batch of 3000 50/2 Sonnars completed February 9, 1948. Have fun with the conversion.

[Brian Sweeney]

Originally Posted by archive59

A couple more pictures of the Schneider/Compur Rapid. Am I correct in thinking that the flash sync connector is an ASA bi-post connector? And would that also have been added when this lens was hacked?

Retina Xenar- this looks like it came from an old Retina camera. Though about that myself. The mount looks like a Summar. hacked- yes, long time ago?

On the Postwar Sonnar: the optics are larger diameter, and the optics module is larger to accommodate it. The lenses with Serial Number above 3M will not fit the focus module of the J-8 and J-3.

[john neal]

Originally Posted by Brian Sweeney

On the Postwar Sonnar: the optics are larger diameter, and the optics module is larger to accommodate it. The lenses with Serial Number above 3M will not fit the focus module of the J-8 and J-3.

Oh no! So I have bought a dog? No pun, dexdog - thanks for the info.

Brian, is there no hope to get this into LTM, or is it like the Helios to LTM hack? BTW, I was holding on to your package until this arrives, so I could send you the "leftovers" - looks like the won't be any now.....

[Brian Sweeney]

It's a great lens, not a dog. But: to hack into LTM you need a focus mount with a larger diameter than a J-8. I gave my Postwar CZJ 5cm F2 away with a Contax II as a gift to a friend. It is a great lens- on the right camera.

[john neal]

Ah well, maybe I need a CZ to LTM adapter after all.............

[Brian Sweeney]

I use an LTM adapter for my Zeiss Opton 50/1.5 Sonnar. I still prefer hacking the optics into a regular focus mount.

I did my 17th 5cm F1.5 conversion, will be showing some shots after the next nice weather day. It's a SN255 series Sonnar "T", prewar. Uses the same heavier brass of the pre-war lenses, aperture ring marked to F11 but closes down to F16. Has the internal set screws holding the rear module in like the later Sonnar "T"s, the set screws are not on the uncoated lenses. AND... The mystery coating of the front element of my SN175 block Sonnar looks just like this one. I've read that Zeiss experimented with coatings on lenses, did not mark them with a "T". I've seen two 175 block Sonnars like this, and after seeing the 255 block lens- suspect it was done at the factory.

[haempe]

Interesting lens on ebay.

Glass seems dead, but the body looks like a good base for further use...

[john neal]

Sold for a high price, given the state of the glass.

Another conversion at item no: 350485107332 - looks like a Jupiter mount, but it has the original aperture ring. I wonder how high this one will go?

[haempe]

Originally Posted by john neal

Sold for a high price, given the state of the glass.

Ouch, the ending price is really a bit on the crazy side...

[haempe]

Has someone noticed this lens before?
I'm curious. I own the M42 version like the one in this link, a very early one sold with the Contax S+D, which has a quite similar barrel.
The later versions for Praktica are a lot larger and bulkier.
Is this conversion into LTM a custom-job? Looks very well-made...

[Shade]

We have got some serious hackers here I see! Nice conversion guys, how hard and how long would such a project take usually?

[haempe]

Originally Posted by haempe

Has someone noticed this lens before?
I'm curious. I own the M42 version like the one in this link, a very early one sold with the Contax S+D, which has a quite similar barrel.
The later versions for Praktica are a lot larger and bulkier.
Is this conversion into LTM a custom-job? Looks very well-made...

Bump.
Someone an idea?

[Brian Sweeney]

Finally the image loaded.

Looks like a custom job, custom machining. Maybe could start with a telephoto lens for the rear Tongue style cam. The 5.8cm focal length is too long to use a 50mm focus mount. Most conversions use a single-helical, rotating cam. The cam is cut, indexed, to translate the motion of the 58mm optics down to the 51.6mm RF. Problem is- the lens must come to the exact position on the camera for the index to be accurate. M-Mount makes it easy because of the lock. This lens- double helical, not as prone to errors. Required the indexed cam to be internal, line up with the tongue.

[haempe]

Thanks, Brian.
Is the motion of all M42 optics during focussing similar or need every lens his own computing/machining?
Or, simple spoken, is a M42 -> LTM adapter possible?

[Brian Sweeney]

If you had a 50mm focal length lens, such as a Pentax 50/1.4, is very close to the Leica standard. You could use a 42mm Universal mount to 39mm mount, provided it is the proper depth for the backfocus. Then- fabricate a cam. The motion of the optics in the helical is correct.

I'm tempted to do this with a Nikkor 50/1.4 AIS. The nikon is a nominal 51.5mm focal length, and I have the correct adapter for F-Mount to M-Mount. Just need to make a cam of the correct length. The focus would be correct, no translation required. Now- the 5.8cm F1.4 and 55/1.2, would need to correct the movement of the cam as Amedeo does with his adapted 55/1.2 Nikkors.