Takumar repair

[Patriot]

Have anyone ever taken apart a Takumar 135mm 2.5? I dropped my lens and now the A/M switch is stuck. It doesn't move freely anymore unless the little tiny pin in the back is pushed in. I haven't found much help online and the only other instruction I found were for the 3.5 version. There is a Chinese written guide but the screws seem to be different. Also that guide is geared toward focus adjustment. Any help would be much appreciated.


Chinese instructions: Pentax M42 135mm f2.5 Ãè*ײz

Thank you,
-Hunt

 

[BrianV]

The SMC Takumar is different from the ones prior to it: the late ones have a mechanism to allow wide-open metering.

This is one of those cases where you need the lens in front of you to figure out. Also some gotcha's: like if you remove the mount off of a Canon FD 50/1.4, all the ball-bearings fall out.

 

[Patriot]

Thank you

It doesn't seem too hard to figure out. I just wanted to make sure before opening to find the problem. Maybe I can make the first guide then. haha

Are you talking about that pin that gets pushed in by the camera to close blades?


-Hunt

 

[BrianV]

The SMC series of lenses have a cam that is tied to the aparture ring to transfer the aperture setting to the metering mechanism. This is separate from the Pin that actually stops down the lens during the exposure. The pre-SMC lenses only have the stop-down pin.

 

[Patriot]

If I post a picture will you be able to tell the difference?

 

[BrianV]

Post a picture of the namering and the rear of the lens. If the ring has "SMC" somewhere on it, I expect to see a Cam and a place for a locking pin at the rear of the lens.

 

[Patriot]

I would say that the Helios didn't do too bad taking these pictures. Really nice without that glass adapter.

 

[BrianV]

That is the later version with the Cam in it for metering wide-open on the Later M42 mount Pentax cameras. It should be very close to the instructions you found for openng it. You might try contacting Kim Coxon who runs Pentax-Manuals.com.

PENTAX MANUALS

He has been busy the last few years, but worth using the Contact button on his site. Tell him you work on C-130s, he is an RAF pilot.

 

[Patriot]

Thank you so much for the help once again. I never thought that photography would introduce me to so many interesting people. I'm learning a lot from you every time you help me out. I hope that he answers because I never spoken to a pilot before.

-Hunt

 

[compur]

Have anyone ever taken apart a Takumar 135mm 2.5? I dropped my lens and now the A/M switch is stuck. It doesn't move freely anymore unless the little tiny pin in the back is pushed in.

That is exactly how all SMC Takumars are supposed to operate. If it didn't operate that way before, you fixed it when you dropped it. The A/M switch is only supposed to move when the lens is mounted on a camera (which is what pushes in the little pin on the back of the lens).

 

[BrianV]

I don't have any SMC Pentax lenses, they are different from my Super-Tak 50/1.4. Mine is now very different, converted it to Leica M Mount.

 

[Patriot]

Have anyone ever taken apart a Takumar 135mm 2.5? I dropped my lens and now the A/M switch is stuck. It doesn't move freely anymore unless the little tiny pin in the back is pushed in.

That is exactly how all SMC Takumars are supposed to operate. If it didn't operate that way before, you fixed it when you dropped it. The A/M switch is only supposed to move when the lens is mounted on a camera (which is what pushes in the little pin on the back of the lens).

That's good thing to know before I took it apart for nothing then.

I don't have any SMC Pentax lenses, they are different from my Super-Tak 50/1.4. Mine is now very different, converted it to Leica M Mount.

If I come across another SMC takumar lens I'll throw it your way. Heck I have three carl Zeiss lens coming in. I don't know if they are any good in IQ but you can have one (if you don't already have one in your collection.)

 

[BrianV]

Carl Zeiss lenses are very, very good- will certainly be interested!

I've converted a Tessar from M42 to Leica mount, and a Exakta mount Tessar to Contax mount. Much less expensive by several hundred $ than finding them in those mounts.