LTM mount 12 o'clock misaligned

[jaeger]

Advertisement (gone after registration)

I just bought a 2nd second copy of a Summitar 5cm and realized it's not aligned to 12 o'clock but instead at 2 o'clock.  The first copy (I sold it few years back) was aligned at 12... I think but I might be wrong... I think I would have post this question few years back if it was misaligned.  I found most images on the internet that this lens mounted on digital M are pointing at 2 o'clock.

Here is the questions, is it possible to make it at point to 12, just for my pet peeve... has anyone done it?  I have some degrees of CLA skills so I can take it apart and put it back without any issue. 

P.S. please don't tell me to get over it, etc...  I am asking people who have an aligned copy or have done it and have the solution.

[adan]

Double-checking:

1) The Summitar is collapsible - you have to pull it out and turn it to the left to lock it for use

2) On a digital M, you must be using an LTM-M adapter.

3) Neither of those have hard detents (or "clicks") to position the lens alignment - you simply turn until the metal binds and the lens can be turned no further, either in mounting the lens on the adapter, or pulling it out and rotating it to lock in the "out" position.

If all that is correct, then:

- Might try a different LTM-M adapter. There is no guarantee that the lens threads on such adapters start and "bind" at exactly the same angular position. Depends on who made the adapter and when. And to what extent the threads have been worn away (or perhaps dented) with use, causing the "binding" to occur at other than the original point.

- The lens may need an internal CLA.

The "turn and lock" mechanism appears to be an L-shaped groove/track (maybe 2?) machined in the lens tube, with a guide pin down inside the focusing base (perhaps not visible without disassembly). The lens tube groove slides along the pin outwards to full extension, and then is turned left as the "foot" of the L slides along the same pin, sideways. If the far tip of the foot of the L has been filled with compacted "grunge" over the decades - or itself dented - that may be blocking the lens turning the last few mm for perfect alignment.

As in:

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

[Ecar]

In my experience, this is often an adapter issue. As Andy says, trying a different brand might work (or not).

[Pyrogallol]

Remember that many older screw lenses are designed to align at the 2 o’clock position, so that you can see the settings when you have an auxiliary finder in the shoe on the camera top blocking the view from the top.

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

Edited September 11, 2020 by Pyrogallol

[250swb]

As said above the lens should mount at 2 o'clock on an LTM body, so fitting it to an M body with a modern LTM adapter will also set it to 2 o'clock. I believe there is a period Leica LTM adapter that will put the lens to 12 o'clock but I can't remember how it is identified because 2 or 12 o'clock so what.

[pippy]

2 hours ago, Pyrogallol said:

Remember that many older screw lenses are designed to align at the 2 o’clock position, so that you can see the settings when you have an auxiliary finder in the shoe on the camera top blocking the view from the top.

This.

Philip.

[a.noctilux]

Advertisement (gone after registration)

I confirm that with Leitz adapters and Leitz screw mount lenses that I use,

when mounted on M, all stop at 1:30 or 2 O'clock depending on "wear or what else".

 

[jaeger]

8 hours ago, adan said:

If all that is correct, then

Yes, all are.  I am amazed that you drew everything out.  Thanks!

6 hours ago, Pyrogallol said:

view from the top

Yep exactly looks like this

5 hours ago, 250swb said:

put the lens to 12 o'clock

I keep the same adapter I use on my previous summitar.  I think it was just that lens is different and that's all.

 

[adan]

Sorry I misinterpreted the location of a "2 o'clock" position. I always consider lenses from the photographer's viewpoint (behind the lens ).

It is possible the LTM adapters are intentionally set up that way to prevent interference between the LTM lens's depressible focus tab, and the M cameras' frame-selection lever - that issue was brought up in a different recent thread here.

[farnz]

On 9/11/2020 at 2:54 AM, jaeger said:

I just bought a 2nd second copy of a Summitar 5cm and realized it's not aligned to 12 o'clock but instead at 2 o'clock. 

Oh no!  All your pictures will be tilted.

Pete.

[jaeger]

6 hours ago, farnz said:

Oh no!  All your pictures will be tilted.

Pete.

I am only up to page 160 of your post of the view thru older glass.  For sure I will post some pictures soon.

[farnz]

15 minutes ago, jaeger said:

I am only up to page 160 of your post of the view thru older glass.  For sure I will post some pictures soon.

Nearly halfway then.  I look forward to it when you feel ready.

Pete.