Who are we?  Featured Cameras  Articles  Instruction Manuals  Repair Manuals  The Classic Camera Repair Forum  Books  View/Sign Guestbook

Contax 139 Inconsistent exposure Log in | Log Out | Topics | Search
Moderators | Register | Edit Profile

Classic Camera Repair » Maintenance & Repair » Contax 139 Inconsistent exposure « Previous Next »

Author Message
Top of pagePrevious messageNext messageBottom of page Link to this message

Eddypolak
Tinkerer
Username: Eddypolak

Post Number: 1
Registered: 08-2013

Rating: N/A
Votes: 0 (Vote!)

Posted on Friday, August 30, 2013 - 07:22 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

The camera in question has not been used for years but it was lightly used and well cared for. I put a film and batteries in the other day and all appeared to work well until at frame 30 the camera stopped working.

I got the film processed and saw that the first frame was fine but thereafter each one was selectively over exposed. By that I mean each had soft edged vertical bands in various positions. All frames look different. Areas not fogged looked OK so I am thinking metering is OK. It certainly behaved OK in shooting

One mistake I made was to use 1.5v alkaline batteries not silver oxide but I can't see that would be the cause. Of course I could be wrong....

The processing lab suggested a light leak but wouldn't that mean each frame would look similarly fogged? It wouldn't explain a complete ceasing of operation at frame 30 either. I thought 'shutter' but wouldn't that produce horizontal bands if misbehaving as its a vertical shutter?

Any ideas? If permitted I could upload a sample frame.
Top of pagePrevious messageNext messageBottom of page Link to this message

Donnie_strickland
Tinkerer
Username: Donnie_strickland

Post Number: 182
Registered: 09-2006

Rating: N/A
Votes: 0 (Vote!)

Posted on Friday, August 30, 2013 - 08:25 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

It sounds as if you have two different problems here. I think the lab is right about light leaks, which would not necessarily show in the same place on every frame. You are correct in your analysis, that a vertical shutter would produce horizontal bands. Jon Goodman has instructions for light seal replacement on the Contax 137MA here:
https://kyp.hauslendale.com/classics/seal/Contax_137_MA.pdf


As to the other problem, that of camera shutdown, I have no advice except to try different batteries, which you may have already done.
Top of pagePrevious messageNext messageBottom of page Link to this message

Eddypolak
Tinkerer
Username: Eddypolak

Post Number: 2
Registered: 08-2013

Rating: N/A
Votes: 0 (Vote!)

Posted on Friday, August 30, 2013 - 09:44 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Thanks that's a useful reply. I have some new batteries to try. If the camera wakes up with new batteries I'll replace the seals. If it doesn't I'll have a nice ornament. I don't think I'd spend money to fix it as I have just bought an OM1 that works perfectly.
Top of pagePrevious messageNext messageBottom of page Link to this message

Michael_linn
Tinkerer
Username: Michael_linn

Post Number: 100
Registered: 04-2011

Rating: N/A
Votes: 0 (Vote!)

Posted on Friday, August 30, 2013 - 10:51 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

This camera has a mirror damper flywheel which produces some of the same problems as the well-known Canon flywheel issue when the lubricant gives out after 20 years or so.

That would be my first guess. Alkaline cells should be no problem at all.
Top of pagePrevious messageNext messageBottom of page Link to this message

Eddypolak
Tinkerer
Username: Eddypolak

Post Number: 3
Registered: 08-2013

Rating: N/A
Votes: 0 (Vote!)

Posted on Saturday, August 31, 2013 - 04:03 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

I will have to look into that flywheel issue. Looking at the light seals more closely I can see the door one is very compressed so I am onto JG for replacements.

As for the shutdown I am a little embarrassed that cleaning the battery contacts again and doing my my best to tighten the cover/holder brings camera back to life. D'oh! Must have just loosened a little in use.

The poorest bit of build on the camera is the battery cover which is plastic and has a very shallow slot for tightening. The slot soon wears making tightening difficult. I will modify now to make it easier to tighten.

Thanks for your advice.
Top of pagePrevious messageNext messageBottom of page Link to this message

Glenn
Tinkerer
Username: Glenn

Post Number: 1091
Registered: 07-2006

Rating: N/A
Votes: 0 (Vote!)

Posted on Saturday, August 31, 2013 - 07:56 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

The slot on this type of battery cover was originally designed to take a small plastic tool - supplied with camera when new and depending on make of camera also designed to do other functions as well. Of course things being what they are, this little tool soon goes 'walkies' and the ever present coin in the pocket is used - with dire consequences to the shallow slot in the plastic cover.

Simple mod is to drill two small holes in the cover and make a small pin wrench from a 'U' shaped piece of piano wire inserted into suitable locating holes drilled in a small length of wooden dowel or plastic rod. To stop the drilled holes being mangled, it is important to keep the two pins parallel and fixed at the correct spacing by some means. As stated I make this 'spacer' out of dowel or plastic rod, but a small piece of rectangular wood or plastic held in position with adhesive tape will do the job just as well.
Top of pagePrevious messageNext messageBottom of page Link to this message

Rick_oleson
Tinkerer
Username: Rick_oleson

Post Number: 1355
Registered: 07-2006

Rating: N/A
Votes: 0 (Vote!)

Posted on Saturday, August 31, 2013 - 10:26 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

It's pretty difficult to forgive that kind of design at the Contax price point.
Top of pagePrevious messageNext messageBottom of page Link to this message

Eddypolak
Tinkerer
Username: Eddypolak

Post Number: 4
Registered: 08-2013

Rating: N/A
Votes: 0 (Vote!)

Posted on Saturday, August 31, 2013 - 11:54 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Thanks Glenn I was thinking of doing much the same mod so glad it's worked for you. I never had the special tool - perhaps I never realised what it was and threw it away immediately.
Top of pagePrevious messageNext messageBottom of page Link to this message

Donnie_strickland
Tinkerer
Username: Donnie_strickland

Post Number: 183
Registered: 09-2006

Rating: N/A
Votes: 0 (Vote!)

Posted on Saturday, August 31, 2013 - 02:51 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Glad that's all it was -- and Rick, I concur.
Top of pagePrevious messageNext messageBottom of page Link to this message

Michael_linn
Tinkerer
Username: Michael_linn

Post Number: 101
Registered: 04-2011

Rating: N/A
Votes: 0 (Vote!)

Posted on Saturday, August 31, 2013 - 04:02 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Yes, the battery cover is just soft plastic, a carryover from the Yashica FX-3 and FX-D. They are identical. That place in India which repped parts used to supply a decent replacement for about fifty cents, but they have not offered them in years.

Yashica had a problem with FX-2 metal battery covers which were nicely machined and chrome plated. But any outgassing from a battery seemed to lock them up tight.
Top of pagePrevious messageNext messageBottom of page Link to this message

Jeffk
Tinkerer
Username: Jeffk

Post Number: 90
Registered: 10-2011

Rating: N/A
Votes: 0 (Vote!)

Posted on Saturday, August 31, 2013 - 06:02 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

On cleaning the contacts, the batteries in my 167MT corroded from lack of use one time and made a bit of a mess. I cleaned everything and replaced the batteries, but in later use I found that the camera would sometimes shut off at random times, and I traced this to the batteries. Rotating the batteries would fix the problem for a while, but the permanent fix was taking a Dremel grinder to the battery contacts and then dabbing a little bit of conductive grease on all of them. No more problems, ever.

Add Your Message Here
Post:
Bold text Italics Underline Create a hyperlink Insert a clipart image

Username: Posting Information:
This is a private posting area. Only registered users and moderators may post messages here.
Password:
Options: Enable HTML code in message
Automatically activate URLs in message
Action:

Topics | Last Day | Last Week | Tree View | Search | User List | Help/Instructions | Program Credits Administration