Contax 645 Problem

[Chris Pook]

Hi,

I came here looking specifically for advice on my Contax 645. I shot 3 rolls of film when the camera arrived, last month. Put them in for developing. Shot 12 more rolls on holiday. Got home to find that none of the 3 rolls I first submitted had been exposed. Bugger. Put in a couple of my holiday rolls for development. 1 was exposed, 1 was not. So, they are not being exposed at all.

I'm trying to identify the fault. Any advice would be most welcome. I'm coming down to thinking mechanical fault in film back or a fault in the links between the body and the back. Had some discussion on other groups, and I think I can discount some of the following;

Dark slide; yes removed, camera does not function with it in place.
Multiple exposure switched off.
Film correctly loaded - can see 'Advance to here' line on film, indicating film is loaded he right way around.
Film is spooled onto bottom reel at the end of the film...
Film carrier loaded and clicked into place in back, when loading film.
Checked camera function with back removed - aperture and curtain function as expected.
No exposure info printed on the edges of the film.
Film type / exposure numbers show clearly on the edge of developed film.

Getting a bit desperate... Have loved using the camera, I so wan t to work now!!!

Any advice most warmly received.

All the best,

Chris

 

[biggles3]

Given that you have an intermittent fault (some film was exposed) can you confirm that the unexposed film was exactly that and not simply massively underexposed? Which modes were you shooting in? Have you checked the aperture blades on your lens(es) - are they sticking occasionally?

 

[Chris Pook]

hi, and thanks for the reply. Actually, no way I can tell if the firm was underexposed or unexposed. The fault is binary. Some rolls are completely fine. Other rolls are not. The fault does not occur intermittently from one exposure to the next. I am no expert (clearly!) but to me this suggests... Well, actually I have zero idea what it suggests!

 

[biggles3]

We do have a mystery on our hands - it's a pity I can't see the camera. I suppose it's going to be a process of eliminating variables... Question: when you load the film, do you simply remove the film insert and leave the back on the camera or do you remove the entire film back? If entire films work or don't on a binary basis, it suggests an intermittent electronic fault that is precipitated by changing a roll of film.

 

[Chris Pook]

Hmm, you kind of can....

I shot some video through the lense, but I cannot post a link yet. I will later.

I have decided to take the camera in for inspection, maintenance, repair.

Annoyingly I work away 9 weeks at a time, so it will be ages yet.

 

[biggles3]

Keep us posted - it's not a fault I've ever come across before. I'm intrigued. Thankfully, there are still some spares knocking about for repairers to work their magic...

 

[dirk]

We do have a mystery on our hands - it's a pity I can't see the camera. I suppose it's going to be a process of eliminating variables... Question: when you load the film, do you simply remove the film insert and leave the back on the camera or do you remove the entire film back? If entire films work or don't on a binary basis, it suggests an intermittent electronic fault that is precipitated by changing a roll of film.

Wow, how do you know all this stuff?

 

[Chris Pook]

Yes Biggles 3, those are my thoughts. There are a series of electrical contacts at the bottom of the film back. I have cleaned then as suggested elsewhere with a rubber eraser. Mainly I have not removed the back, but it seems to me that the connection which generates the signal to wind on by one frame may be intermittent. The film always winds on completely at the end. If this is on a separate circuit it may explain the problem, but I don't have a wiring diagram for the camera. Even if I had one it may not make much sense to me.

I shot some fast video though the back of the camera, with the back removed, and as you would expect the aperture opens more fully at the faster shutter speeds. You can clearly see this.

I have shot 90% on Aperture priority- not sure this is relevant to the problem, but I was asked here.

The problem for me is that there is no fast feedback to enable me to fault check, and I am getting reluctant to put film through the camera in trial and error... It is not cheap. But then... Nor was the camera. Staking it in for service and repair seems to be the Answer.

It is v annoying, as I am only home for ten days when next back In the uk, and so it is likely to be my next leave, at Christmas, before I get the thing back. I really wanted to be using it here in Iraq, but until it shoots consistently I am not sure it is worth bringing it.

Hmm... Pentax 645z is starting to look attractive! It is such a long discussion now, though, about the benefits of MF against 50mp Canons, or the new 5d4, when I have an existing array of good canon lenses. This was supposed to be An interesting and fun diversion into MF film, but so far it is just very frustrating!!

Cheers for all your inputs.

 

[biggles3]

Hi Chris,

Why not send a message to Julian Abel at http://www.contaxrepairs.com/ He is in the UK and worked a miracle on a seriously challenging RTSIII which I was about to junk as there was so much wrong with it. It's working a treat and he tidied up a couple of my Contax STs while he was it. He used to work for Contax and knows his stuff - if any one might be able to work out what may be the problem, he's the man. And his charges are perfectly reasonable.

The Contax 645 is a risk as spares are not that plentiful and servicing is a rare art. But I'd urge you to persevere - that fabulous silky shutter, the unbelievable lenses - everyone who's picked up a C645 and fired the shutter wants one... And you can extend the range of lenses if you are prepared to forego AF with Mamiya 645 manual focus lenses. I love the M645 Soft Focus lens and the Auto Bellows N - if you buy an adapter from Zork, the whole Mamiya 645 range of manual focus lenses becomes useable! Marvellous - and of course for macro lovers, that bellows with its swing/tilt/shift mechanisms is a peach. The Contax 645 version is so expensive and rare, it's great to have an alternative. As you can guess from the photo, I have a love of the C645...

Forget the Pentax 645Z - lovely camera but I abandoned my foray into Pentax digital MF after having a real disappointment with the glass. I have been using a Pentax 6x7 for decades and love the lenses but I had terrible problems with softness and chroma on the Pentax 645 digital gear. The camera however was a joy to use.

 

[dirk]

o.k., I stop posting here. I can not compete with that amount of medium format cameras....

I guess these are your P&S for the jeans pocket? :z04_Flucht: