[butangmucat]

Hello,

I am consider acquiring a Carl Zeiss Jena Pancolar lens, specifically in the all black version because it has an A/M switch and seem to have better grease. However, I noticed that the black version comes in both standard version and "electric" version, with the latter being usually cheaper. I understand that the "electric" version is Pentacon's attempt to offer open-aperture metering similar to that of S-M-C Takumars and the Spotmatic F and it has some extra contacts. It seems, however, that these lenses still have the A/M switch. I would like to know if they will still mount correctly on other M42 cameras and adapters. I have a Spotmatic F and a M42 to Sony E adapter which I plan to use with my Sony mirrorless.

Sincerely

[stevebrot]

I would like to know if they will still mount correctly on other M42 cameras and adapters

Whether it will mount cleanly depends on the camera and the adapter. My understanding is that the "electric" CZJ lenses are broadly backward compatible to non-electric Praktica bodies. As a result, they are also broadly compatible to most other M42 bodies. Fouling of the contacts on adapter cut-outs would be the primary concern.


Steve

[antipattern]

I have a few CZJ and Pentacon lenses, some of which are electric. I never had any problems mounting them on my Pentax bodies. Certainly none of them got stuck on my camera, like those with a Ricoh pin are meant to. If you don't want to use them with a Praktica body that supports these electric features, it really doesn't matter.

With regards to the greasing being better for the black versions, I couldn't tell the difference. I have handled quite a few black and silver versions and both seem to be prone to dry helicoids and oily aperture blades. However, they are fairly easy to service and are quickly cleaned and lubricated.

[butangmucat]

I have a few CZJ and Pentacon lenses, some of which are electric. I never had any problems mounting them on my Pentax bodies. Certainly none of them got stuck on my camera, like those with a Ricoh pin are meant to. If you don't want to use them with a Praktica body that supports these electric features, it really doesn't matter.

With regards to the greasing being better for the black versions, I couldn't tell the difference. I have handled quite a few black and silver versions and both seem to be prone to dry helicoids and oily aperture blades. However, they are fairly easy to service and are quickly cleaned and lubricated.

I am more worried whether these lenses would mount all the way into place. I know that the Fujica lenses won't mount all the way in place to allow infinity focus. I would like to know if similar problems exist for these "electric" lenses, both on Spotmatic F and M42 to Sony adapters. It seems that the electric contacts are raised, would they not allow the lens to fully mount in place?

[Na Horuk]

I have CZJ Flektogon 35mm. There is a rod sticking out the back and the A M switch toggles whether it sticks our or is flexible. If it sticks out it can actually hit the camera's AF screw when you try to screw the lens onto the camera (which has m42 adapter mounted). But this is a minor problem. The lens seems to mount normally and I think it has infinity focus
Many m42 lenses will not screw in perfectly to the correct degree (slight misalignment). Usually there is enough tolerance to still get infinity focus.

[yucatanPentax]

I am more worried whether these lenses would mount all the way into place. I know that the Fujica lenses won't mount all the way in place to allow infinity focus. I would like to know if similar problems exist for these "electric" lenses, both on Spotmatic F and M42 to Sony adapters. It seems that the electric contacts are raised, would they not allow the lens to fully mount in place?

The contacts are spring-loaded and depress when mounted.
I've had no trouble using one.

[stevebrot]

Many m42 lenses will not screw in perfectly to the correct degree (slight misalignment). Usually there is enough tolerance to still get infinity focus.

There is a misconception regarding the "misalignment". Having the focus index mark at "12:00" is sort of nice, but has nothing to do with infinity focus. As with all other mount systems, the flange focal distance is established by...ummm....the distance from the focal plane to the face of the body flange. Infinity focus is relative to that distance, which should also be the distance from the lens flange to the focal point when properly mounted. With screw mounts (M36, M39, M42 or whatever) The lens should stop when its face is snug on the opposing flange and not before. If that happens anywhere other than with the index mark at 12:00, it means nothing more than the thread lead-in being at a different point than on a lens that might line up.

I just did a quick survey of the eight thread-mount bodies on my shelf showed and none with the mark at 12:00 for the lenses mounted. All except one of my Spotmatics and the Canon P has the manufacturer-brand lens mounted. I have a few lenses on the shelf that do line up, but only when used with the genuine Pentax M42 adapter and then not with all three of my adapters. Again, flange focal distance with a proper adapter is made by the lens mount face snugging up to the body mount flange. All of my M42 lenses attain infinity focus on all my M42 and K-mount bodies. The same is true for all of my M39 (LTM) on my LTM bodies and on the Bessa R3M.


Steve

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Last edited by stevebrot; 02-21-2018 at 07:53 PM.

[stevebrot]

I would like to know if similar problems exist for these "electric" lenses, both on Spotmatic F and M42 to Sony adapters.

Look at the face of your Spotmatic F. Compare it to the back of your lens. After all, you have both in hand. Is there anything that those spring-loaded contacts will snag on?

Now, compare your Sony adapter to the lens and make the same assessment. The Sony-M42 adapters I have seen have nice smooth faces with no screw holes or other obstacles. If there are doubts, carefully and slowly screw the lens onto the adapter while monitoring those projections and the points of possible interference. When screwed on, the lens flange face should be snug against the adapter face with the contacts fully pressed into their wells.


Steve

[butangmucat]

Look at the face of your Spotmatic F. Compare it to the back of your lens. After all, you have both in hand. Is there anything that those spring-loaded contacts will snag on?

Now, compare your Sony adapter to the lens and make the same assessment. The Sony-M42 adapters I have seen have nice smooth faces with no screw holes or other obstacles. If there are doubts, carefully and slowly screw the lens onto the adapter while monitoring those projections and the points of possible interference. When screwed on, the lens flange face should be snug against the adapter face with the contacts fully pressed into their wells.


Steve

I have got the lens, and they work well. Both of my camera and adapter have smooth mount surfaces. The only thing I was worried was that the lens won't allow infinity focus like the Fujica ones. However the contacts are spring-loaded and it mounts well. However the stop-down pin is a bit too long, and I have to set the lens at M to avoid the pin getting stuck with the open-aperture metering mechanism when mounting. However once mounted, the lens works flawlessly in Auto mode.

[stevebrot]

The only thing I was worried was that the lens won't allow infinity focus like the Fujica ones.

I am glad you got things sorted out. If the lens registers cleanly to the body flange, infinity focus should be fine; assuming, of course that infinity focus for the lens itself is properly adjusted. As for the Fujica problem, those lenses have a prominent ridge at the flange edge that interferes with a clean mount on non-Fuji bodies. A similar issue exists for some variants of Helios 44-3 58/2. The solution with the Fujinons is the same as with the Helios...grind away the obstruction.


Steve