Stuck infinity lock?

[kentroberts]

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A relative recently picked up an M3 with the Summarit 5cm lens at an estate sale, and lent it to me for a bit to play with for a bit. Definitely needs a CLA as shutter speeds below 1/25 are way off but the more immediate concern is that the infinity lock appears frozen. The little button pushes down ok but I am unable to move the focus ring with the button depressed. I've not owned a Leica before so I'm hoping there's something else I should be doing, although my guess is the focus ring is frozen in place. It's likely the camera/lens have not been used in 25+ years. Any thoughts/suggestions? 

[wda]

Since your relative owns the camera I would report your findings to him. The camera clearly needs servicing, at a cost, and it is for him to decide how much he is willing to pay. My guess is comfortably over £100. You might be able to ease the stiffness by repeated gentle exercise, but the shutter is a different matter.

[dpitt]

On 5/5/2023 at 2:12 PM, kentroberts said:

A relative recently picked up an M3 with the Summarit 5cm lens at an estate sale, and lent it to me for a bit to play with for a bit. Definitely needs a CLA as shutter speeds below 1/25 are way off but the more immediate concern is that the infinity lock appears frozen. The little button pushes down ok but I am unable to move the focus ring with the button depressed. I've not owned a Leica before so I'm hoping there's something else I should be doing, although my guess is the focus ring is frozen in place. It's likely the camera/lens have not been used in 25+ years. Any thoughts/suggestions? 

Lenses for use by military were modified to be locked on infinity (the enemy is never that close) Maybe your lens is an old military one?

[kentroberts]

Thanks for the responses! 

[1joel1]

On 5/7/2023 at 11:35 PM, dpitt said:

Lenses for use by military were modified to be locked on infinity (the enemy is never that close) Maybe your lens is an old military one?

If the lens has an infinity lock, why would the military need to lock it permanently. Those locks don't accidentally unlock as it takes a concerted effort to do so. 

[spydrxx]

4 hours ago, 1joel1 said:

If the lens has an infinity lock, why would the military need to lock it permanently. Those locks don't accidentally unlock as it takes a concerted effort to do so. 

To keep curious fingers from moving it off the predetermined setting! Heaven knows there are posts on this site of curious people mishandling their lenses, disassemblying them and unable to get them back together properly.

[dpitt]

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4 hours ago, 1joel1 said:

If the lens has an infinity lock, why would the military need to lock it permanently. Those locks don't accidentally unlock as it takes a concerted effort to do so. 

This modification makes the lens a lot less attractive for private use. An effective way to discourage soldiers from stealing it, and also a good way to help avoid misuse in inexperienced hands.

[frame-it]

On 5/8/2023 at 3:35 PM, dpitt said:

Lenses for use by military were modified to be locked on infinity (the enemy is never that close) Maybe your lens is an old military one?

very interesting, is there any documentation or other reading material regarding these military modifications?

[Susie]

If it is a screw mount Summarit, the screw/M mount adaptor needs to have part of it cut away to clear the button on the back of the infinity lock to enable it to be depressed.  Genuine Leica ones have this, but some third party ones will not:

[kentroberts]

9 hours ago, Susie said:

If it is a screw mount Summarit, the screw/M mount adaptor needs to have part of it cut away to clear the button on the back of the infinity lock to enable it to be depressed.  Genuine Leica ones have this, but some third party ones will not:

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It's a bayonet mount.

[TomB_tx]

I've bought several old lenses where the helicoid grease was so solidified you could not move the focus, so this isn't unusual.

[kentroberts]

14 hours ago, TomB_tx said:

I've bought several old lenses where the helicoid grease was so solidified you could not move the focus, so this isn't unusual.

I think this is probably the issue. The shutter on the M3 that the lens is attached to is also not 100%. A good CLA should get everything back to proper working condition.