Is it SAFE to collapse lenses on the M10

[LucisPictor]

Advertisement (gone after registration)

It is obvious that any lens built not to touch the shutter of a film camera won't do so on a digital one either; the register distance is the same. ...

It's just that the register distance is not the distance between mount and shutter but between mount and film/sensor.

So, it is theoretically possible that the shutter curtains in one model are closer to the mount than in another one.

[jaapv]

Yes, this has been analyzed many times on this forum. The results can be found in the FAQ. Except for the old type 90/4.0, the problem to watch out for is the diameter of the rear of the lens.

 

Question:
Is it safe to collapse a lens with retractable tube (e.g. 50mm Elmar) into the body of the M8 or M9?
 
Answer:
First of all, Leica says in the manuals for the M8 and M9: „Lenses with retractable tube can only be used with the tube extended, i.e. their tube must never be retracted into the LEICA M8/M9. This is not the case for the current Macro-Elmar-M 90mm f/4, whose tube does not protrude into the camera body even when retracted. It can therefore be used without any restrictions.“
On the other hand many users have reported in this forum that they regularly retracted the tubes of other lenses into the camera bodies without any problems.
Let‘s look for some facts:
There are two reasons for Leica‘s warning about collapsible lenses in the manuals:
1. The „throat“ of the digital M (the open space between the bayonet mount and the shutter) is much narrower than with film Ms. If someone would mount or dismount a lens with it‘s tube retracted and hold it in a certain angle it might touch and scratch the sides of the „throat“. Therefore you should only mount or dismount a lens when the tube is extended.
2. The retracted tube might touch and damage the shutter.
If you look into the body without a lens you see two black metal ridges above the shutter. The distance between those two ridges is approx. 25mm. The diameter of a retractable lens tube is at least 27mm (in most cases considerably more). So if the tube hits anything it will be the ridges and not directly the shutter. This does not make it safe, for pressure on these ridges, which are made of rather thin metal, might interfere with or even damage the shutter.
Do the tubes of retractable lenses touch the ridges?
I measured 24mm as the distance between the surface of the camera‘s bayonet and the ridge. Let us stay on the safe side and say: a tube which enters 22mm or more into the body will be critical or dangerous. That is certainly the case for the collapsible 4/90 Elmar (old type ILNOO; 11631, 11131, which was produced from 1954 to 1968 - so not to be mixed up with the current Makro-Elmar-M, 4/90).
How long are the tubes of other collapsible lenses entering into the body?
Some examples: For the tube of the collapsible version of the 2/50mm Summicron (screw-mount) I measured less than 14mm when it is collapsed, so I see no risk at all that it could touch the ridges. For the Elmar-M 2.8/50 (last version) it‘s 20.5mm, same for the first version of the 2.8/5cm Elmar with M-mount or it‘s 3.5/5cm M-mount precedessor. But a „red dial“ 3.5/5cm from 1951 (screw-mount) gives a very risky result of 22.5mm; for a nickel 3.5/5cm from 1932 I measure 20.5mm again. The 2.5/5cm Hektor had the longest tube I know: 23mm, which is dangerous! The Summar‘s and the Summitar‘s tubes were shorter than those of the Elmar (18mm). For all screw-mount lenses the adapter, which is necessary to mount them on an M, gives 1mm more space. The different results for the 50mm- or 5cm-Elmars from different times show that individual measurements of certain lens types are not reliable for every other lens of this sort. There may be variants in the tube‘s design, even protruding sharp edges on the ends of a tube.
So before retracting a lens into the body of  one should measure the retracted tube (always fixed on infinity) looking especially for protruding edges. Anything which is 22mm or longer should be never retracted but the extended tube secured by a Dymo band that it won‘t retract accidentally.
A new thread in the German forum about collapsible lenses for the M taught me that my explanations about collapsible lenses used with M-cameras are incomplete: http://www.l-camera-forum.com/leica-forum/forum-zur-leica-m9/269373-elmar-2-8-50mm-m9-2.html#post2295115
I dealt a lot with the risk of the tube touching the shutter or scratching the throat of the camera. Though these risks cannot be ruled out completely they are not the whole story. The real risk is caused by the broad end of the tube hitting the little roller of the focus sensor lever and its screw. You can see it on the photo here: http://www.l-camera-forum.com/leica-forum/forum-zur-leica-m9/269373-elmar-2-8-50mm-m9-2.html#post2295443
You can test this with a M-body for film when you open the rear window (without film) and look through the opened shutter and lens. When you push the collapsible lens tube inwards you may see it scratch at the roller or its screw. So this is no new problem for the digital M but for all M models as they all have the same roller and screw for the focus sensor lever at the same position.
The 2.8/50 Elmar-M (last version) may cause the most trouble - with all Leica-M bodies! - as the black end of the tube is broader than on earlier collapsible lenses. The tube of the last version of the 50mm Elmar may also have more play in the lens mount than earlier collapsible lenses, so it may hit the roller at a "bad" angle.
Older lenses are not completely free of this problem. I measure the same diameter of 3,04cm for the broad tube's end of a post-war Summitar. The other collapsible lenses seem to have about 1 millimeter less, though there may be variances.
So to collapse a 2.8/50mm Elmar-M - or any other collapsible lens on an Leica-M-body - may cause a conflict between the end of the lens tube and the roller for the focus lever. Leica's caveat about using collapsible lenses in the M8 or M9 (M-E) is therefore justified - though the same caveat is true for any other Leica-M body.

*minimally edited to make it universally applicable and some typos - jaapv

[Ko.Fe.]

I still have question and it looks like unanswered one. 

How much of the dust or else collapsing lens bring into the camera, on its sensor?

[jdlaing]

1 hour ago, Ko.Fe. said:

I still have question and it looks like unanswered one. 

How much of the dust or else collapsing lens bring into the camera, on its sensor?

No more than when you remove or change lenses.

[Alberti]

On 2/7/2017 at 2:29 PM, jdlaing said:

Years ago I had a conversation with a technician.

That person told me, at the time on an M9, that a collapsible lens should be extended when mounting to avoid damaging the throat of the camera. Once mounted it could be safely collapsed.

Today I was at the Leica Store Beaumarchais where they have an 50mm Elmar-M. No said the man, looking at my M240, you can’t use this on a digital body.

- I was allowed to mount it extended. He was very afraid I scratched the black ring on the back of the lens. 😓
Don’t think he’ll ever be able to sell it.

albert

 

[Herr Barnack]

I previously owned a 50/2.8 Elmar (non-M version) and used it without problem on my M-P 240.  However, I did not collapse the lens into the camera.  The guy at Leica Store Beaumarchais can relax. 

I cannot give any information/advice regarding use of this lens on the M10, though.

Edited January 9, 2020 by Herr Barnack

[lct]

Advertisement (gone after registration)

3 hours ago, Alberti said:

Today I was at the Leica Store Beaumarchais where they have an 50mm Elmar-M. No said the man, looking at my M240, you can’t use this on a digital body. [...]

This guy doesn't seem to know that the latest copies of the lens have been sold with 6-bit coding. Beware that the bottom of the tube is very close to the roller cam though.

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!

[UliWer]

Your illustration shows where the „problem“ of collapsible lenses lies: it is not the shutter but the roller cam!
Though this is no novelty of digital bodies, the „problem“ exists since Barnack‘s Leica II and Berek‘s Elmar. Everybody who likes can test it. With a screw-mount body you can easily feel the resistance of the roller cam, when you collapse some lenses: the Summitar is a good candidate, as its tube was a little bit broader. Barnack and Berek could live with the „problem“; only in times of the Internet and customer warnings it becomes an „issue“.

Of course it is still true that the lens should be attached  and released only when it is extended. Since the „throat“ of the digital M bodies is much narrower there is a risk to scratch the throat when you attach or release the lens in an unfortunate angle. That‘s also the reason you cannot use the old collapsible 4/90mm Elmar with a digital body: its rear end is too broad to enter the narrow throat.You should not even try, 

[lct]

2 minutes ago, UliWer said:

[...] Though this is no novelty of digital bodies, the „problem“ exists since Barnack‘s Leica II and Berek‘s Elmar. [...]

The bottom of the Elmar-M's tube is larger than that of the Elmar though. Novelty since 1994 but nothing specific to digital i agree.

[UliWer]

vor 5 Stunden schrieb Herr Barnack:

I cannot give any information/advice regarding use of this lens on the M10, though.

I am not giving any recommendations to do so, but I tried the 50mm Elmar (older version as well as Elmar-M) with M8, M9,  M10 - and collapsed them. No problem.

If someone tries to collapse it - do it slowly and carefully the first time - and realizes the resistance of the roller cam he should stop the movement. The Elmar-M has a black plastic ring at the tube’s end, which increases the diameter and therefore the risk of collision with the roller cam. Leica Customer Care may cut off the black plastic ring at the tube‘s end to solve the „problem“.

P.S: looked again at my my Elmar-M: I am not sure whether it is plastic or metal, it is black and obvious. People from the German Forum have reported that they had cut off this ring by Customer Care in Solms or Wetzlar - on recommendation by the staff there. 

Edited January 9, 2020 by UliWer

[lct]

10 minutes ago, UliWer said:

[...] The Elmar-M has a black plastic ring at the tube’s end, which increases the diameter and therefore the risk of collision with the roller cam. [...]

This ring is full metal as i sense it but i may be wrong.

[UliWer]

Yes, it looks like hard plastic, but touching it feels like metal.

Btw: I do not see any problem to use a 50mm Elmar or any other collapsible lens and keep it extended. A lenses purpose is to take picture not to be collapsed.

We usually use lenses which are at least as big as an extended Elmar, and times when you wanted to put your camera into you vest pocket are gone: the cameras are too heavy. 

The only exception would be the old collapsible 4/90mm Elmar as it takes a lot of room in your bag when it is extended. But there is no way to collapse this lens in a digital body. 

 

[lct]

Indeed and the Elmar-M remains one of the shorter if not the shorter 50mm M lens in extended position if i'm not mistaken. Here with the Summicron 50/2 v4.

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!

[UliWer]

The Summarit-M is probably shorter than an extended Elmar - no reason for the Summarit to become more popular (which is a typical misconception of Leica users: if I use Leica, it must be extremely expensive, otherwise it‘s no good...).

[lct]

15 minutes ago, UliWer said:

The Summarit-M is probably shorter than an extended Elmar - no reason for the Summarit to become more popular (which is a typical misconception of Leica users: if I use Leica, it must be extremely expensive, otherwise it‘s no good...).

+1. Great little lens too, with less character than the Elmar-M though but this is a matter of tastes obviously.

[UliWer]

There is always some guessing what might be the next „retro“ lens for the M after the 28mm Summaron and the Thambar.

I was always making fun about a new 50mm  „Elmar-M asph“ - thinking that aspherical lenses made no sense for a triplet. Though recently I learned that Willy Merté was experimenting with aspherical surfaces for the Tessar during the thirties at Zeiss Jena.

So if Mr. Karbe, or any other „optical gnome“ in the caves of Wetzlar might have some spare time...

Though I fear that they would not realize a new „old“ Elmar - first out of fear that it might be collapsed in a digital body and some user took it as a risk and second because they might find out that such a lens could outresolve the Summicron Apo. Asph. 

Edited January 9, 2020 by UliWer

[Alberti]

21 hours ago, lct said:

This guy doesn't seem to know that the latest copies of the lens have been sold with 6-bit coding. Beware that the bottom of the tube is very close to the roller cam though.

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!

Having the 6-bit code is indeed very convincing that the lens is made in the digital era. The roller cam is not visible in a digital M like this , but I assume the structure is the same for all Leica's - it is part of the rangefinder which retained its structure - placement being the most important thing, and thickness of the roller is secondary - for some 65 years. 

It all depends on how well the tube retainer is made - in my Macro-Elmar-M I can feel some play when inserted (wobble?) but not with this 50mm Elmar-M.

Anyway, I should go to another shop and have another try. (I have a Canon macro lens based on the Tessar and it is very very good).

[lct]

My favorite 50 in good light. BTW the roller cam is just in front of you when you remove the body cap .

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!

[MikeMyers]

I was asking in another thread about using, and collapsing a 50mm collapsible Summicron, #1327463 in my new M10.

The advice was to check the manual, which on page 135 says "Lenses with retractable barrel can only be used with the barrel extended, I.e. their barrel use never be retracted into the camera......."

Not wanting to risk damaging anything, I'm going to forget about this idea.  

[Advertisement]

Hallo,

Look here: Interesting Leica gear

[Reini]

vor 3 Minuten schrieb MikeMyers:

Not wanting to risk damaging anything, I'm going to forget about this idea.  

And if you should forget, can you put a 2-3mm around? rubber ring around the tube.