Contaflex Infinity focus

[Deleted member 88956]

So now looking through Contaflex Super BC on ground glass I cannot focus to infinity. This is based on split image indication not actual field test. Near focus appears pretty close to split image indication. Mounted Tessar front. There is nothing obvious that would imply a problem. Camera works fine, shutter, rear curtain, mirror, all respond as expected. Tessar front group locks in without an issue, solid fit, just right. Absolutely nothing on visual inspection that would suggest focusing issue.

Anyone with ideas?

 

[Kino]

The helicoid goes to infinity on the lens barrel?

I don't have a Super BC but I do have a Super B at home I can check later tonight. Can't say I have ever noticed this problem...

 

[Deleted member 88956]

The helicoid goes to infinity on the lens barrel?

I don't have a Super BC but I do have a Super B at home I can check later tonight. Can't say I have ever noticed this problem...

Infinity marker on lens barrel lines up perfectly. There seems to be nothing visible on markers misalignment. I have t assume split image would have had to be correct. Camera is in near new condition, everything works perfectly and I see nothing that would suggest anyone had ever worked on it.

 

[Helios 1984]

Maybe the helicoid is just a wee bit out of alignment ? If it’s anything like the Contaflex IV, you just need to loosen the back screw to adjust the helicoid ‘til the focus on your ground glass matches with the split image, and then retighten the screws.

 

[Deleted member 88956]

Maybe the helicoid is just a wee bit out of alignment ? If it’s anything like the Contaflex IV, you just need to loosen the back screw to adjust the helicoid ‘til the focus in the ground glass matches with the rangefinder and then retighten the screws.

Do you mean the small cover screw on left upper back?

 

[Helios 1984]

I've just checked the Super BC, and the focusing adjustment procedure isn't the same as on the Contaflex IV. Actually, it's very different so, please, scratch my previous post. The good news is, the procedure looks slightly less P.I.T.A than on the Contaflex IV.

Here's the service manual

Read PDF page 10, under "Lens Focusing". The concerned diagrams are I11.2 and I11.20.

Note:
Ignore Screw 222 shown on diagram I11.19, it isn't related to the 4x 222 screws mentioned in the "Lens Focusing" section.

 

[Deleted member 88956]

I've just checked the Super BC, and the focusing adjustment procedure isn't the same as on the Contaflex IV. Actually, it's very different so, please, scratch my previous post. The good news is, the procedure looks slightly less P.I.T.A than on the Contaflex IV.

Here's the service manual

Read PDF page 10, under "Lens Focusing". The concerned diagrams are I11.2 and I11.20.

Note:
Ignore Screw 222 shown on diagram I11.19, it isn't related to the 4x 222 screws mentioned in the "Lens Focusing" section.

Thanks a lot. Looks like all details are in place. It may be a while before I jump on it, but surely worth a try.

 

[Kino]

The helicoid goes to infinity on the lens barrel?

I don't have a Super BC but I do have a Super B at home I can check later tonight. Can't say I have ever noticed this problem...

Well, it is too dark outside to confirm or deny! Sorry. I'll check when I get a chance in the daytime.

 

[Deleted member 88956]

Well, well, well. I have found where the problem is, but nothing I thought was even possible.

First, I swapped the Tessar 50 front with Pro-Tessars 35 and 115. Both do infinity spot on.

Second, as I have exact same second Super BC, which has no issues doing infinity (but has somewhat stiff focus) and used the Tessar 50 on first one. Again, no problem with infinity. Using the bad Tessar on the other body delivers same infinity off-set.

So conclusion here is easy, the Tessar front is off the mark. Comparing two, bad one is newer, front knurled ring is actually slightly thicker, but what is more important, on the back there is a brass shim that is significantly thinner. So it appears that front group is not registering, when locked in, at required plane.

Has anyone run into this kind of problem? Has Zeiss made a camera that used exact same lens combination, but was NOT Contaflex and differed enough to have that brass shim so much different in production?

For now I'm just fairly certain the Tessar front group is not from a Contaflex. There are no signs of any work having been done, so I rule out any tinkering of some super-repairman who knew "better" than Zeiss engineers.

 

[Kino]

It could be a Tessar from an earlier Contaflex model and the specifications changed in an upgrade in production.

Mine is a Contaflex Super B. Look close at the mount and see if it is the one that is "bad" on the BC.

This is obviously not the same mount on the left and is a Pantar 50mm on a Prima model, but it's the only other Contaflex I have for comparison.




If you don't have it:

Butkus:

Contaflex Pocket Companion --
https://www.cameramanuals.org/zeiss_ikon/zeiss_ikon_contaflex_book.pdf

Which reminds me; I have to go make a generous donation to him and his archive. I use it ALL THE TIME!

 

[Deleted member 88956]

It could be a Tessar from an earlier Contaflex model and the specifications changed in an upgrade in production.

Mine is a Contaflex Super B. Look close at the mount and see if it is the one that is "bad" on the BC.

This is obviously not the same mount on the left and is a Pantar 50mm on a Prima model, but it's the only other Contaflex I have for comparison.

View attachment 295837


If you don't have it:

Butkus:

Contaflex Pocket Companion --
https://www.cameramanuals.org/zeiss_ikon/zeiss_ikon_contaflex_book.pdf

Which reminds me; I have to go make a generous donation to him and his archive. I use it ALL THE TIME!

But can you mount either front group on either body? Cosmetically my two Tessars are practically identical. The only cosmetic I see is the front knurled ring being somewhat different height and that back side brass shim clearly different thickness, by a mile.

 

[Kino]

No, that's why I said I didn't have another model of the Contaflex Super to compare it to.

The book in the link mentions some close up auxiliary lenses; any chance this is one of those? How close can you focus with it compared to the other?

 

[Deleted member 88956]

No, that's why I said I didn't have another model of the Contaflex Super to compare it to.

The book in the link mentions some close up auxiliary lenses; any chance this is one of those? How close can you focus with it compared to the other?

No, mine fit correctly either or, both are just Tessars 50/2.8. You basically cannot tell them apart unless compared very closely.

The only way this could have happened at production, if there was another camera with same lens design but for whatever reason front/rear groups were arranged differently. The difference in thickness of that brass ring (shim) is probably between 0.5-1.0 mm. If I cannot find a logical answer, I will probably see if I can take it apart and see if there is something else to adjust. I'm not touching the camera mounted side as it works perfect with Pro-Tessars.

 

[Kino]

Agreed. Someone might have cobbled a lens together from whatever parts they could muster to sell the camera.

 

[Nicholas Lindan]

What happens if you just remove the shim? Does that move the lens back far enough that you can now focus at infinity?

 

[Deleted member 88956]

What happens if you just remove the shim? Does that move the lens back far enough that you can now focus at infinity?

That is integral to front group. Looks like disassembly is needed to get to it, which I will. The thing is that since Pro-Tessar work as expected and that set of add-on lenses I believe started with version III to the end of series, if I'm right, there would have to be a different model that took basically same front group with same bayonet mount. The shim I'm referring to looks exactly same as on the properly working one, just thicker. If there is a way to "drop" lower into the barrel, it might be just it.

 

[Deleted member 88956]

More to this Contaflex bizarreness. Just received a Super with Tessar and 85/4 Pro-Tessar. All works fine on infinity on this one, and both lens groups from this delivery switch to my other two Super BCs without problems and work well at infinity all the same.

However, for reasons I cannot yet see, while the Tessar from Super fits onto Super BC fine, a Tessar from either Super BC does NOT fit onto Super. It does not drop in enough and thus cannot be fully set within lens mount. Anyone can confirm same when switching Tessar 50 form Super BC to Super?

I do have another Super I picked up for 29EUR and that may shed some light on the problem. Need to wait a few days for that though.

 

[Kino]

This brochure lists two discreet Tessar 50mm lenses;
https://www.pacificrimcamera.com/rl/00220/00220.pdf

 

[Deleted member 88956]

Thanks for brochure link, it helps in other respects. I may get a hold of the Rapid just to see if for some reason there is the optical issue. My last post was about strictly on bayonet mount not taking one lens while taking all others. And seemingly same bayonet on two other cameras taking all without a problem. From vers. III they all are supposed to be the same and interchangeable.

 

[Nicholas Lindan]

[the lens] does not drop in enough and thus cannot be fully set within lens mount.

It could be the lens has a longer threaded portion/back structure that is bottoming out in the camera before the lens completely seats on the camera.

 

[Deleted member 88956]

It could be the lens has a longer threaded portion/back structure that is bottoming out in the camera before the lens completely seats on the camera.

The bizarre thing is ALL lenses I have (6 total) fit on ANY of the 3 bodies, proper fit, proper focusing, but that one Tessar 50 that came today with the Super works fine on its own body but does not fit any other. It appears the shape of its bayonet wings are not exactly same, some differences in how they are cut off and that could be the problem.

 

[Deleted member 88956]

Continuing on my own, have received today next Super body with Tessar 50 and now I am convinced whatever Zeiss did with that particular Tessar front, it does NOT fit Super BC. Two "Super" cameras, same result. And to re-confirm, all later lenses fit without a problem on those Supers. There is definitely a difference in bayonet shape on these Tessars. Cannot think it was a production misstep. Maybe someone who owns Super AND Super BC can confirm they got same issue when swapping Tessar 50 groups? It would put it to rest, if same result.

I'm lost on this one, but need to keep that in mind, note SNs and what they can and cannot do.

 

[John Wiegerink]

My Contaflex collection is north at my cottage and I will check for you next week when I get back up there. I have two BC's, one SuperB and three Supers. Should be able to find out something, but I don't remember having any problems. JohnW

 

[Deleted member 88956]

My Contaflex collection is north at my cottage and I will check for you next week when I get back up there. I have two BC's, one SuperB and three Supers. Should be able to find out something, but I don't remember having any problems. JohnW

That would be nice. My two Tessars 50 on Super have all chrome rear while all later ones have a brass shim. Looking at shape of bayonet on lens’ side the all chrome are somewhat different from later ones too.

 

[Kino]

Have you seen this: https://en.wikipedia.org/wiki/Contaflex_SLR#Contaflex_lenses

"There was also a Zeiss Pro-Tessar M 1:1 supplementary lens, that kept the focal length of 50mm but allowed 1:1 reproduction. The effective speed of the M 1:1 lens is f/5.6. The 50mm standard front elements, as well as the Pro-Tessar M 1:1 elements, were different between the early models III, IV, Rapid and Super with the old model of Tessar, and the later models Super (new), Super B, Super BC and S with the recomputed Tessar. It appears that the mount was very slightly modified, and it seems physically impossible to mismatch the elements as the journal diameter above the bayonet mount had been reduced by approximately .006""