Removing the M mount on a Super Angulon F4

[Beemermark]

I have a Super Angulon F4 I purchased to use on my LTM bodies. I can't figure out where the grub screw is that holds on the M adapter. Thought I knew but when I loosened the one on the barrel the M adapter won't budge. Can someone take a picture and post it. TIA.

 

[TenEleven]

I do not know about the details for this exact lens, but on my L/M Summicron 35/2 v1 the grub screw is indeed what holds the M portion of the mount.

In my case when I first removed it the M mount adapter/piece was exceptionally tight.
I needed rubber stoppers to remove it. I gave the threads a good clean with cotton buds and naphtha and now it's a lot easier to dis- and re-assemble.

Be careful though - my L/M adapter piece had a shim inside. It's very thin. It is not needed for use on LTM as both RF and lens focus are in perfect agreement on my l-mount cameras, but make sure to not lose or maim it.

 

[Beemermark]

But where is the grub screw located. Can you past a picture of it on your 35 Summicron?

 

[coogee]

I've had the 35mm Summicron LTM/M and the grub screw was located on the side of the mount, not the rear of the lens if that makes sense (ie; still visible when the lens is mounted on a camera.) Can't speak to the Super Angluon in particular.

 

[oldwino]

It’s a very tiny screw on the side of the mount. When I say tiny, I mean tiny. Something like 1.5mm. I had to buy a screwdriver just to take it off. There was no shim underneath.

 

[TenEleven]

Belatedly here's a picture, the screwdriver I am pointing at it has just the right size. Flathead 1.2mil blade. I am not sure what that would be in imperial.

And yes, it makes sense that the shim would not be present for all lenses depending on tolerances.

 

[Dralowid]

The SA is not on my list of lenses with a removable M mount but then my 'list' might be wrong.

 

[yossi]

 

[Beemermark]

Thanks for the pictures. That was the only grub screw I could find but I'm dumb as to why that held the M adapter in place. I had managed to loosen it but couldn't remove the adapter so I thought no way is that it. So next question - should I remove it all the way (and it will be lost forever), turn it a few more turns, remove it and throw it away?

 

[pyeh]

Beemermark, that grub screw is the tiniest thing in the world, and you have to pretty much fully remove it in order to disengage the M adapter. I screwed the grub screw back into the M adapter afterwards, so I wouldn't lose it.

 

[TenEleven]

I know you're not being entirely serious, but just in case here's what I do - I undo the screw fully because I have had too many cases of a not-screwed-out-enough screw getting mangled and then getting partially ground into the threads. And if that happens - well now your really having capital P problems...

So what I do is remove the screw fully, undo the adapter, screw the screw back in then put both (and in my case the shim) in a appropriately labelled small Ziploc. This way even if the screw decides to go on its own little adventure it is not gonna be able to go far.

 

[Beemermark]

Got it-🙂. Thanks everyone. Can’t put the screw back in (not steady enough) but why is it even needed?

 

[TenEleven]

It is likely insurance that in the act of mounting and removing the lens on the camera (which involves a twisting motion) you don't end up unscrewing the lens a fraction of a turn and end up with potentially unsharp photos.

 

[Beemermark]

It is likely insurance that in the act of mounting and removing the lens on the camera (which involves a twisting motion) you don't end up unscrewing the lens a fraction of a turn and end up with potentially unsharp photos.

Well I've (like thousands of other Leica users) have never had an issue with the M adapter coming loose on an LTM lens. I think the only reason for the grub screw was Leica wanted to show a new 21mm lens that would only fit on their new M3.