Isco Tele-Westanar 135/3.5 M42 Semi-Auto for Edixa

luisalegria · Expire: 2018-01-18

I got this in a lot with other things, and as I really don't collect Isco's or similar lenses in M42, I am selling it.
I did want to try it out though, as it is a rather interesting piece.

A classic "zebra" finished lens from the great days of the German SLR industry. I guess this dates from some time between the late 1950's to maybe 1964 or so, as I am lacking an Isco serial number reference. Its also got the ditinctive "window" type aperture/DOF display. I have seen this on some early 1960's Schacht lenses also. Isco was of course a spin-off of Schneider. Isco after WWII generally made lenses for the mass market as compared to Schneider which dealt with the upper end of the industry.

This particular model is a bit unusual because it is not just the typical preset aperture lens of the time, but a transitional "semi-automatic" lens intended for use on a very specific line of cameras, Edixa. In, fact, it is a triple-mode lens -

Semi-Auto on Edixa -

The lens can be "cocked" using the sliding latch (see pictures below), whereby the aperture will remain wide open, even as the taking aperture can be set for some smaller aperture. When the auto pin is pushed by the cameras auto mechanism the lens is automatically stopped down. But for the next shot it has to be cocked again. This of course is not unique to this lens, a similar system was used by Asahi for early Takumars, by Zeiss and Schneider for some Exakta and M42 lenses, etc.

Why Edixa ? Edixa's were M42 mount cameras, but their lens mount thread was skewed. This lens when fully screwed into a regular M42 camera will not have its auto pin in the same place a regular M42 auto lens would, it would be about 20 degrees off. The push plate wont hit the pin. Similarly a regular M42 auto lens on those Edixas won't work in auto mode either.

Semi-Auto with dual shutter cable -

This lens also includes a shutter cable socket, intended for use with a double-ended shutter cable. One end went into the camera shutter socket, the other on the lens. The lens could be cocked as above, and it would automatically stop down when the shutter cable fires the shutter. This mode could be used on any M42 camera. This is a very unusual mechanism on an M42 lens.

Preset -

The aperture mechanism is also a preset - typical on German style presets, the stop can be set by pulling back the ring and moving it to the preset aperture. Then the aperture ring will turn between the preset aperture and wide open. This mode can of course be used on any M42 camera.

Other than the curiosity regarding the special semi-auto modes, this is a normal M42 lens, and can be used on any M42 camera or DSLR with standard M42 adapters. Its a very conventional 4-element 135mm lens it seems. Minimum focus is 1.5 meters. I got it in good condition, I just had to clean some haze behind the rear element.

Performance is fine. It works well wide open, giving very good sharpness to my mind.

Samples - some taken with extension rings.

The bird -

crop -

Ymmot · Joined: 24 Sep 2011 Posts: 168

Maybe the shutter release socket is useful with certain bellows units (and non auto tubes)?
Now it does not really matter I guess, any sort of m42 tubes, auto or non auto, can be had for peanuts anyways. Wink

ManualFocus-G · Expire: 2014-11-24

That's a nice looking vintage lens, and the results have a vintage edge to them too Smile

woodrim · Joined: 14 Jan 2010 Posts: 4060 Location: Charleston

Looks like an older version of mine. I rather like the ISCO lenses.

fatdeeman · Joined: 13 Jun 2009 Posts: 780 Location: UK

Nice looking lens and great results, as always! I love pic 3