Hacking A.Schacht lenses

Some years ago I bought an A.Schacht f/3.5 35mm lens with LTM mount the rear lens element of which was

somewhat fogged, probably to some aging of the lens cement. I mentioned this purchase here:

http://www.photo.net/leica-rangefinders-forum/00BaxC

As I am the proud owner of an Edixa SLR with M42 mount (which actually works despite of the poor workmanship -

Edixa cameras were virtually slammed together) plus an A.Schacht f/1.8 50mm and f/3.5 135mm lens I recently

bought a f/3.5 35mm lens with M42 mount which was described with "focussing stiff". This usually is not too difficult

to fix. Anyhow, it turned out that this lens must have been smashed on the floor so badly that the focussing helicoid

went oval and will never move again. (The "stiffness" the seller encountered was the friction between the focussing

ring and the stuck helicoid).

So this lens was almost useless ... until I remembered that 35mm LTM lens I bought years ago. The 35mm LTM

lens was quite bulky, much longer than a f/2.8 35mm Komura LTM lens I own. Could it be possible that A.Schacht

used the same lens design for both LTM and M42?

Removing the rear lens element of both lenses was very easy. The lens elements were of identical diameter, identical

thickness and identical design (a cemented element). The one from the M42 lens had two light scratches but was

clear otherwise.

So I put the M42 rear lens element into the LTM lens. Sometimes if you swap single lens elements you have to

recalibrate the focus (since lens sets were matched in the factory). I checked the focus with the "reverse collimator

method", using my Canon7s (which has a hinged rear door - you must have access to the film gate to use this

method) and the focus was correct. So very probably this lens element will fit into the 35mm LTM lens and will be

tried out in the near future.

That's quite a hack!! Patiently awaiting results

I've seen some/one Kiev Lens Jupiter 3 on the big auction site back in Jan, and it had no rear mount only the optics!! I considered an adaptation of sorts... never got very far, just played with the thought!!

I hope it works out!!

Winfried,

This would be a nice project lens to write about here.

Brian Sweeney often does similar hacking. I got from him a Paxette :Luxon 50/2 hacked into LTM by using a J-3

shell. He will soon get me a Sonnar 5cm/2 hacked into LTM by using a J-8 shell.

If you want to see some really bad lens hacks, check ebay for Kinoptik lenses. Kinoptik was a major french manufacturer for cine lenses (as the brand name implies), and many of their lenses are marked "Cine Special". However, there are two or three guys selling those lenses with LTM mount. The focussing mounts of the f/2 40mm lenses they sell look as if they were cannibalized from Industar lenses, and the M42 300mm lenses look like they were assembled from components found in a junkyard... I always wonder how happy the buyers will be using a lens designed for 18x24mm cine format for 24x36mm.

BTW, it is quite unusual to use a lens design designed for an SLR wide angle lens on a rangefinder lens, as A.Schacht did. I was quite happy that I could save the LTM lens with the M42 lens components. A SLR wide angle lens requires a retrofocus design which is not necessary for a rangefinder lens, and the retrofocus lenses always are much bigger and need more lens elements than their "standard" counterparts. As mentioned, the Komura f/2.8 35mm rangefinder lens is much smaller than the f/3.5 35mm A.Schacht lens.

Here's a really bad hack:

http://cgi.ebay.de/Kinoptik-Paris-for-M42-300mm-3-5-300mm-3-5_W0QQitemZ370065601447QQihZ024QQcategoryZ93780QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

I know a german dealer who told me that he once sold a Kinoptik or Angenieux lens (don't remember it precisely) to one of these lens hackers and was not very surprised to find it on ebay some weeks later with a completely different lens mount (and, of course, completely different price).

Regarding bad hacks, Kinoptics, etc.: I notice that people pay good money for Lens Babies and Holga cameras, etc.

I've even seen Holga owners posting questions about how to get the highest quality scan of Holga negatives.

Maybe the hacked Kinoptics lenses vignette, or have fall-off towards the edges, in some special appealing way.