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500mm C Tele-Tessar shutter misfire

W

wingit

New Member
Hello all. I'm new to this forum. I've been reading posts from here for a few years though. I have a question for the collective as I am stumped.

I purchased a lens recently, and received it on Friday. It is a 500mm C Tele-Tessar with the Synchro-Compur shutter. My camera is a 500 C/M. The lens is in great shape and the seller swears it was in working order when it left his possession. Here is the problem: When I depress the shutter release on the camera, the mirror goes up, the rear curtains open, but the shutter in the lens does not fire. It is when I remove pressure from the shutter release button that the mirror drops, the rear curtains close, and then the shutter in the lens trips. The fire sequence is reversed. So, of course, with the mirror down and the rear curtain closed, this is going to result in unexposed frames.

This happens at all shutter speeds, all aperture settings, and I am testing with the film back off so my eyes can confirm what my ears hear.

All three of my other lenses are operating normally.

So, what gives? Anyone had this problem before?

Thanks in advance for your help.
David
 
wingit said:
Hello all. I'm new to this forum. I've been reading posts from here for a few years though. I have a question for the collective as I am stumped.

I purchased a lens recently, and received it on Friday. It is a 500mm C Tele-Tessar with the Synchro-Compur shutter. My camera is a 500 C/M. The lens is in great shape and the seller swears it was in working order when it left his possession. Here is the problem: When I depress the shutter release on the camera, the mirror goes up, the rear curtains open, but the shutter in the lens does not fire. It is when I remove pressure from the shutter release button that the mirror drops, the rear curtains close, and then the shutter in the lens trips. The fire sequence is reversed. So, of course, with the mirror down and the rear curtain closed, this is going to result in unexposed frames.

This happens at all shutter speeds, all aperture settings, and I am testing with the film back off so my eyes can confirm what my ears hear.

All three of my other lenses are operating normally.

So, what gives? Anyone had this problem before?

Thanks in advance for your help.
David
Click to expand...

Dear David,

It might be that the release mechanism in the camera body is sluggish and needs cleaning and relubricating. Does the lens ostensibly work when manually triggered away from the camera? Can you try the lens on a second body? Alternatively, the shutter release mechanism on the lens may be sluggish such that the sequence of events in the camera can overtake those on the lens. This may explain why some lenses work but the 500mm does not.

The fact that other lenses may work does not necessarily mean that the body is without defect; there is an interplay between the springs in the lens shutter and the springs in the camera body controlling mirror/blinds etc. that ensures the correct sequence of the timing of events - shutter closes - aperture stops down - mirror up - rear curtain opens - shutter fires - rear curtain closes then on retensioning/film advance - mirror down - shutter and aperture opens. These events are not rigidly coupled but depend on certain steps taking definite times in a correct and predetermined sequence; it is therefore the combination of your lens on your body that is the key to the problem.

I had a similar problem with my 150mm CT*; it behaved fine on some bodies but as you described on one other body. I ended up stripping both lens and body, cleaning and reassembling then all was fine. In my case it was the body that was the culprit; the other lenses provided enough torque to overcome the friction in the camera body release mechanism but the 150mm did not.

Best wishes,

Richard.
 
Dear David,

Richard gives good advice but it does suggest that the mechanism of the lens is slow to follow the drive key of the body. All these things can be checked with service tools and a service to whichever item is the cause will correct the problem.
 
I have a 30mm C lens that does the same thing. I had it serviced by David Odess, not for that but a general CLA. When returned it started doing as you describe. I sent it back to him and when returned it worked fine. Now many years after the work it is doing it again. It didn't get used that much either. To use it now I have to release the shutter button just a little bit and the shutter will trip. Release a little more and the camera will complete it's cycle. Aggrivating!
 
Hasselblad service stations have tools that set the exact points that the body drive and lens drive make certain actions, they don't just turn, they move in steps. This is so that if a lens or body are service individually you can be sure that the two items work together when attached. It is not always possible to say that a certain fault must be the lens or body, a fault in either can produce the same symptoms. It should always be the case that a body or lens serviced separately will work together if they have been reassembled using the factory tools but any service technician would always be a little bit more confident if they had the camera and lens to check together.
 
In the last two years I have purchased three different 500mm F8 C chrome-finish Zeiss Tele-Tessars from KEH Camera in Atlanta GA USA. All three of them had shutters that would not open, they were returned to KEH, and I got complete refunds, including -all- shipping charges.

I inquired with David Odess regarding a CLA for the 500mm, and he replied that he does not work on that lens. It requires special factory-made tools, which he does not have. KEH Repair Servixces replied back after a bit, that they could not work on it, either. I saw an auction on Ebay, a 500mm chrome lens, the owner said they had sent the lens to Paul Ebel, for a recent CLA. Paul has recently done CLA work for me, although I did not inquire about the 500mm. He probably can work on it. Probably worth inquiring if interested.

Mr. Paul Ebel
Paul Ebel Lens Services
420 21st ST N Suite #2
PO Box 141
Menomonic, WI 54751

(651) 335-8759
 
Daniel Unkefer said:
In the last two years I have purchased three different 500mm F8 C chrome-finish Zeiss Tele-Tessars from KEH Camera in Atlanta GA USA. All three of them had shutters that would not open, they were returned to KEH, and I got complete refunds, including -all- shipping charges.

I inquired with David Odess regarding a CLA for the 500mm, and he replied that he does not work on that lens. It requires special factory-made tools, which he does not have. KEH Repair Servixces replied back after a bit, that they could not work on it, either. I saw an auction on Ebay, a 500mm chrome lens, the owner said they had sent the lens to Paul Ebel, for a recent CLA. Paul has recently done CLA work for me, although I did not inquire about the 500mm. He probably can work on it. Probably worth inquiring if interested.

Mr. Paul Ebel
Paul Ebel Lens Services
420 21st ST N Suite #2
PO Box 141
Menomonic, WI 54751

(651) 335-8759
Click to expand...

Daniel Unkefer said:
In the last two years I have purchased three different 500mm F8 C chrome-finish Zeiss Tele-Tessars from KEH Camera in Atlanta GA USA. All three of them had shutters that would not open, they were returned to KEH, and I got complete refunds, including -all- shipping charges.

I inquired with David Odess regarding a CLA for the 500mm, and he replied that he does not work on that lens. It requires special factory-made tools, which he does not have. KEH Repair Servixces replied back after a bit, that they could not work on it, either. I saw an auction on Ebay, a 500mm chrome lens, the owner said they had sent the lens to Paul Ebel, for a recent CLA. Paul has recently done CLA work for me, although I did not inquire about the 500mm. He probably can work on it. Probably worth inquiring if interested.

Mr. Paul Ebel
Paul Ebel Lens Services
420 21st ST N Suite #2
PO Box 141
Menomonic, WI 54751

(651) 335-8759
Click to expand...
 

In order to open the lens you must first remove the frontmost elements by unscewing the threaded outer retaining ring using a rubber friction wrench thereby gaining access to the inside of the lens tube; the "special factory made tool" referred to above can easily be made; you basically need a "T" key which additionally has two spiggots welded to the horizontal upper face of the "T" at the correct distance from one another such that these may engage in the two holes on the inner retaining ring in the lens; such a tool can be made from a 10 mm Allen bar by cutting off a piece of suitable length to form the crosspice, welding it on to the "vertical leg" of the "T" and then welding the two spiggots onto the uppermost face. If you look through the front of the lens, you can see the two holes in the retaining ring that has to be unscrewed; the nature of the beast then becomes clearer.

By clamping the tool in a vice (using an Allen bar - as opposed to a cylindrical bar - gives two flat parallel faces so that the tool will not slip in the vice), lowering the inverted lens over the tool so that the spiggots engage and twisting the lens tube in an anticlockwise direction will open the inner retaining ring. This may be quite tight because when the lens was first assembled, CZ (in their (un)wisdom used loctite on the threads (totally unnecessary in my opinion) so heating the lens with a hot air gun up to about 75 degrees Celsius will greatly facilitate removal. The tool also needs to be machanically stable against any tendency to flex tortionally - that is why a 10mm Allen bar is needed.


The 350mm Tele-Tessar has a similar construction but requires a slightly diffently dimensioned tool.

The same Synchro-Compur shutter is used in all C/CT* lenses; it is therefore advantageous to have one or two shutters in excess that can be exchanged when a built in shutter starts behaving "out of specification" - the most common problems are too slow slow speeds and a self timer that "never ends". The errant built-out shutter can then be overhauled "at leaisure" and returned to the pool.

Hope this helps.

Best wishes,

Richard Hughes.
 
I would only like to add that the iris control ring on the back of the shutter is focal length dependent so if you do want to switch shutters the iris control ring for the lens has to changed. There is a very slight difference in the shutters between the first 'C' lenses and later 'C' lenses, the most obvious difference being the VXM control.
But why change the shutter at all? Just service it!

RICHARD HUGHES said:
The same Synchro-Compur shutter is used in all C/CT* lenses; it is therefore advantageous to have one or two shutters in excess that can be exchanged when a built in shutter starts behaving "out of specification" - the most common problems are too slow slow speeds and a self timer that "never ends". The errant built-out shutter can then be overhauled "at leaisure" and returned to the pool.

Hope this helps.

Best wishes,

Richard Hughes.
Click to expand...
 
Douglas Fairbank said:
I would only like to add that the iris control ring on the back of the shutter is focal length dependent so if you do want to switch shutters the iris control ring for the lens has to changed. There is a very slight difference in the shutters between the first 'C' lenses and later 'C' lenses, the most obvious difference being the VXM control.
But why change the shutter at all? Just service it!
Click to expand...

... because it takes me about 35 minutes to exchange shutters on a 80/100/120/135 Planar for example and considerably longer to strip the shutter innards (self timer, escarpment, shutter blades etc.) clean, sparingly lubricate, reassemble and adjust to within specification; (a bit like changing a spare wheel after a puncture rather than removing, patching, vulcanising, remounting and rebalancing the wheel - but each to his own).

As all my (30) synchro-compur shutters originate from the later CT* lenses, I was unaware of any differences between the C and the CT* series.

I am not quite sure what part is being referred to under the term "iris control ring"; all my "raw" shutter corpuses (as supplied by the Compur Werke here in Munich to CZ) are identical (as opposed to the mount to which the shutter is fixed by the 5 countersunk screws mounted around the circumference of the "rear mounting ring"); in fact I bought extra shutters as spares from "Nordic" (the then German agent for VH) and there were no questions asked as to which lenses these spares were intended for.

Nevertheless an interesting discussion.

Best wishes,

Richard Hughes.
 
Just to clarify a couple of points the 'C' lenses ran from 1957 to approx 1980 and during this time Zeiss improved the lens coating and these lenses and these lenses are marked T*. However other more subtle improvements were also made without there being an overtly obvious external sign such as the change to the VXM control, its there if you know what to look for. Only the old 'C' lenses have a VXM control, this feature did not carry over to the later CF series.
All of this series of lenses had the same basic shutter with different iris control rings and all of these shutters were retained by 6 screws.
During the early 80s the CF range of lenses took over from the C range and these lenses had 2 main types of shutter and they were both retained by 5 screws and in this case the iris control rings were the same and the variations for the focal length were handled in a different way.
These shutters have been further revised over the years and later ones were retained by 3 screws.
I am sorry if anything I said has confused you
 
Thank you all for your replies. Unfortunately I haven't yet been able to spend time with this lens. However, after reading all these replies this evening, I did look at it a little closer.

I noticed that the shutter in the lens releases when the lens drive coupler is almost exactly straight up and down, (12 o'clock) whereas on the other lens I was comparing it to, the shutter tripped noticeably sooner (closer to 1 o'clock). And on my camera body, the key stops exactly straight up and down while the shutter release button is depressed and held. Once you let up on the shutter release, the key rotates slightly more. Thus, it would appear that when I depress the shutter button, the lens is on the verge of tripping, but doesn't do so until I release the shutter button.

I am unable to verify this operation with any other camera as I don't know anyone else with one. I hope to get to a service center soon, but am wary of finding a qualified technician any where within my reach (Colorado, USA). And if it takes special tools to get into this lens then my hopes are further dwindled.

Thank you all again and I will update this thread as I get new information/results.

David
 
Your description confirms what I thought. A service or CLA if you prefer will fix it.There is no difference in repairing a 500 to any other lens but it is just a bit harder to dismantle and reassemble.
 
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