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Overhaul of Contax Planar 1.4/50mm T* MMJ
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PostPosted: Sat May 28, 2011 11:54 am    Post subject: Overhaul of Contax Planar 1.4/50mm T* MMJ Reply with quote

I've got this lens with oily aperture and stiff focusing ring, but with good optics. So complete overhaul was necessary.
For someone who knows what he does. Photos are self explanatory I hope.

Remove the front and rear optical group first to avoid scratches.

As usually only assembling. Disassembling is just reverse process.







Fix the aperture with three screws in plastic ring










Fix the aperture/optical block assembly with three screws












Adjust infinity on camera and fix it with focusing ring


Put back name plate ring
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PostPosted: Tue Sep 13, 2011 11:17 am    Post subject: Reply with quote

Hello BRunner, how did you unscrew the nameplate in the front? I usually do it with a smaller cap, it worked with flektogons or pancolars, but doesnt work with this one.

I also tried to open the rear part, I got stuck pretty fast, I unscrewed everything I could, but it seems like a screw is holding it from the inside. (its on the opposite side of the red dot, I can only see the end of it, in the thread)

Thanks for you help!







PostPosted: Tue Sep 13, 2011 11:29 am    Post subject: Reply with quote

http://www.flickr.com/photos/67470780@N04/


PostPosted: Wed Sep 14, 2011 12:17 pm    Post subject: Reply with quote

The nameplate ring is one piece with filter mount, as you can see on last image. Just unscrew it, it is probably glued, you need to use some force.
The rear part of AE version is slightly different. Maybe there is ring over rear part of lens like on Rollei Planars.


PostPosted: Wed Sep 14, 2011 1:46 pm    Post subject: Reply with quote

BRunner, thanks much for sharing this very detailed report.
I will never have the guts to do that myself on one of my lenses, but for people who dare,
this is certainly going to be extremely useful!


PostPosted: Wed Sep 14, 2011 4:01 pm    Post subject: Reply with quote

Thank you, I finally managed to unscrew the nameplate, and the rest was easy!
Dky!


PostPosted: Wed Feb 15, 2012 12:07 am    Post subject: Reply with quote

This is still a wonderful thread. Thank you for this thoroughly photographed post of the 50mm/1.4 reassembly. I have a 50mm/1.7 and can't seem to remove the nameplate. I'm guessing that they have similar design so I tried grasping the outer rim with a rubber mat and turning firmly counterclockwise, there is now some light play, but not a full release. I'm hesitant to go any further without some sage advice. I also know that I do so at my own risk. Any further guidance would be appreciated.


PostPosted: Wed Feb 15, 2012 8:30 am    Post subject: Reply with quote

1.7 Planar is different. The nameplate ring is screwed inside filter ring and it holds front lens in place too. I can look later.


PostPosted: Sat Mar 24, 2012 9:22 am    Post subject: Cannot remove focus ring Reply with quote

After removing the name plate and the three screws I have problems pulling the focus ring off. It is loose and can be lifted a bit. But it seems at the inside of the focus ring a hook is preventing to remove it.

Any idea what to do?


PostPosted: Thu Apr 12, 2012 7:13 pm    Post subject: Reply with quote

BRunner wrote:
The nameplate ring is one piece with filter mount, as you can see on last image. Just unscrew it, it is probably glued, you need to use some force.
The rear part of AE version is slightly different. Maybe there is ring over rear part of lens like on Rollei Planars.


Did you unscrew by turning it counterclockwise or clockwise?

Your post is an amazing one. I have thought of trying it for my 50mm 1.4 planar for years and never had enough information about it. Mine has the same oily aperture blades and stuck solid too. I actually have two of this lens. Both have aperture problems. I am tempted to take them apart to fix.


PostPosted: Fri Apr 20, 2012 9:56 am    Post subject: Reply with quote

mtjade2010 wrote:

Did you unscrew by turning it counterclockwise or clockwise?

Counterclockwise.


PostPosted: Fri Apr 20, 2012 9:57 am    Post subject: Reply with quote

mtjade2010 wrote:

Your post is an amazing one. I have thought of trying it for my 50mm 1.4 planar for years and never had enough information about it. Mine has the same oily aperture blades and stuck solid too. I actually have two of this lens. Both have aperture problems. I am tempted to take them apart to fix.

Thanks, I'm trying to help other people to fix their lenses.


PostPosted: Thu Apr 26, 2012 1:55 am    Post subject: Reply with quote

BRunner wrote:
mtjade2010 wrote:

Did you unscrew by turning it counterclockwise or clockwise?

Counterclockwise.


Thank you, BRunner. I will try my lens as soon as I gather the tools I need. Than you so much for the post.


PostPosted: Sat May 05, 2012 7:08 am    Post subject: Reply with quote

I finally put all my courage together and worked on my Contax Planar 50mm 1.4 MM version yesterday. It had oily aperture blades and was completely stuck at fully open aperture.

I used a rubber strap wrench and it was easy to turn the front barrel counterclockwise to take it off. The front group of glass wasn't too tight. I was able to just use my finger to turn if counterclockwise and took it off too.

When I tried to remove the back end of stuff I had a problem. One of the 3 screws that hols the bayonet mount plate was so tight that I ruined it. I had to use a micro drill bit to drill off the head of the screw and took the plate off.

The rear group glass also went off without too much trouble. Taking the aperture mechanism off was a challenge. It wasn't obvious where to unscrew in order to get things off. Finally figured it out and the the blades all fell out. After cleaning off all the oil on them it was even more challenging to put them back together. Had to practice many times without the blades before doing it with actual blades included. Assembling the helicoil was quite a challenge too. Took me a few hours to figure out the trick to do it quickly.

Finally I succeeded and adjusted focusing and everything seemed to work properly except that I now have only two screws to keep the bayonet mount plate on the lens. I mounted it on my RTS-2 and it was still firm and tight. I will need to keep in mind that it is not as secure as it was. It looks like will not affect the performance of the lens.

The only thing that I am not exactly happy, besides breaking one of the 3 screws, is that now I can see some tiny dirt on the surface of the glasses inside and out. I used a blower to blow off as much as I could still the glasses are not as spotless as they used to be. I don't want to wipe it with anything. It would only get worse not better. It's still much better than a Planar with frozen aperture. The blades are now clean and snappy. I will try to shoot some Velvia 50 with it soon.