Releasing the infinity / focus lock on the 35mm f/2.8 Summaron lens

[Tom Kershaw]

Hello all,

This is my first post here, I'm usually over at APUG. Could someone explain how to disengage the infinity / focus lock on the 35mm f/2.8 Summaron lens? I've looked at the lens several times, trying to gently press or pull the small "catch" on the focus tab but without success.

Tom

 

[Ljós]

Pull the "catch" towards you/the camera body, the focusing tab is now no longer locked and can be moved to the left, away from infinity to nearer focus.
With a bit of practice, this is one smooth and fast motion. Of all the infinity locks I know, this is the best implementation.

Maybe what's throwing you off is that you try to do it with the lens not mounted to a body? It'll work nonetheless, but it is easier with the lens mounted to a body.

 

[Tom Kershaw]

Pull the "catch" towards you/the camera body, the focusing tab is now no longer locked and can be moved to the left, away from infinity to nearer focus.
With a bit of practice, this is one smooth and fast motion. Of all the infinity locks I know, this is the best implementation.

Maybe what's throwing you off is that you try to do it with the lens not mounted to a body? It'll work nonetheless, but it is easier with the lens mounted to a body.

- You're correct in that I'm trying to unlock the lens off a body. I already have the lens but I'm evaluating whether a Leica could be a sensible camera choice.

Tom

 

[Ljós]

Tom, it is especially sweet on a Leica M2 🙂
I am very happy with my 35mm f2.8 Summaron. The lens element is recessed so far that a lens shade is not necessary. I only add a shade when using a yellow filter. The Summaron is effectively more compact than a 40mm Summicron-C/40mm Rokkor.
All the best, Ljós

 

[coelacanth]

Don't worry, once the lens gets on the camera, you don't really have to think about it. You can release it naturally. Only annoyance is when you focus close to infinity but not quite. Then you'll have to keep the button pushed. Some people remove the lock all together to avoid this. I don't mind because usually DOF takes care of the difference.

And welcome to RFF!

 

[Tom Kershaw]

Ljós and coelacanth,

I've had another look at the lens and still find it difficult to see how the lock is released. Here is a annotated image to assist:

Which of the actions is it?

thanks for your welcome,

Tom

 

[srtiwari]

I have one of these great lenses.
As best as I can see, you do "C", and while it is still pressed in, move the tab "sideways" to try and focus to other distances. Then you can let go of the tab as it only locks at infinity.

 

[LChanyungco]

push in towards the barrel not down towards the flange.

 

[Vincent.G]

C is the correct way to release the infinity lock with the lens mounted on your camera. It is very easy to do.

 

[Tom Kershaw]

After double checking I see the lens is not set at infinity but approx. 7m. Looking at the lens in more detail I can now see what appears to be gunked-up grease between the brass ring and the lens mount, stoping the focusing mechanism from working.

Tom

 

[Ljós]

Tom, I just learned something from your post! Thanks.
You see, both "A and push" and "C and push" work.
The actual movement of the lock is "A and push". The nice thing is that the design is such that when you hold the camera to your eye, and rest the finger in the tab and pull the lock towards you, this movement is "translated" into pushing the lock inwards (A and push).
Both takes about the same force (very little); I always thought of it as pulling the locks towards me, but I now see that the actual movement is pushing the lock inwards towards the center axis of the lens. As I said, a nifty lock! ;-)

When you focus from near to infinity, the lock is automatic. Just move the tab to the right, forget about the lock, it will lock automatically. Very nice!

All the best, Ljós

 

[Ljós]

After double checking I see the lens is not set at infinity but approx. 7m. Looking at the lens in more detail I can now see what appears to be gunked-up grease between the brass ring and the lens mount, stoping the focusing mechanism from working.

Tom

Oh, that explains it. That of course explains your difficulties, then it is not about the lock. You could try to carefully work it loose, but without force. The Summaron is a great, great lens and certainly worth a professional cleaning. Wish you good luck!

 

[kermaier]

"C" is the proper motion. I use the tip of whichever finger I'm using to focus, push it into the infinity lock to release, and leave the finger tip nestled in the concavity of the focus tab to work it back and forth.

I have, and love, the Summaron 35/2.8. I bought mine on eBay, and when I got it the focus was also so stiff that I couldn't really move it. I sent it to Sherry Krauter (Golden Touch) for a CLA, and she did a great job fixing it up.

If the glass is clean and you didn't overpay for the lens, it's a no-brainer -- send to a good tech for service, and enjoy it for the rest of your days. 🙂

::Ari

 

[Tom Kershaw]

Ljós,

thanks for your help. I may make enquiries with repairers.

Tom

 

[kermaier]

Oh, that explains it. That of course explains your difficulties, then it is not about the lock. You could try to carefully work it loose, but without force. The Summaron is a great, great lens and certainly worth a professional cleaning. Wish you good luck!

IMO, if it's so stiff that it feels locked, then you should not attempt to work it loose -- you're more likely to unnecessarily wear or stress the moving parts. Just send it for service right off.

::Ari

 

[Ljós]

Worth a professional repair

Worth a professional repair

Ari is right, I guess if it were possibly to get it moving (without harm) by just carefully trying to focus, you would have succeeded long ago. So if you want to keep the lens, it is time for a professional service. If it is just cleaning and relubing the focus helicoid, it should not be an overly expensive job.

All the best, Ljós

 

[FrankS]

This is one item that is definitely worthwhile spending additional money on to get serviced. It is an older lens so getting the elements cleaned at the same time also makes sense, but again, worth it, IMO.