Interesting M3 Close Focus Issue

[WJJ3]

Here is an interesting phenomena I discovered with my M3, on which there doesn't seem to be much discussion.

I tried the ELMAR-M 50mm 2.8 on my M3 today and was surprised to find that the rangefinder in my camera from 1960 (992***) would not focus the lens, which has a close focus of 0.7 meter, closer than about 0.9 meters. After googling around a bit, I saw that many people are saying that the M3 has a minimum close focus of 1 meter, and that you need to use the DR SUMMICRON to get closer focus (I was also surprised to see some people were bending parts of their M3's focus mechanism as a DIY mod to get lenses to focus closer! YIKES!). The 1 meter limit of the M3 is simply not true however, as my M3 accurately focuses my goggled 35mm 2.8 SUMMARON all the way past its marked close focus point of 0.7 meters, until the focus tab hits the finder goggle (0.65 meter?).

My M3 focuses my 1962 35mm lens accurately to 0.65 meters, but wont focus a late 1990's 50mm lens past about 0.9 meters. Does anyone have this same experience? Is there a list of lenses that the M3 cannot focus to their close focus distance?

I am really curious to know the story behind this issue and whether there is accurate technical information about it.

Thanks to anyone who can fill me in!

 

[kokoshawnuff]

The rangefinder focusing mechanism (the little wheel inside the camera) on the M3 can indeed be bent to focus below the standard 1m minimum distance, but bending it can also throw off the focus at other distances making it only accurate at the new minimum distance. According to some technicians and other with more knowledge than I, this is true of some cameras but not all—for instance I bent my focusing mechanism and it now focuses to ~.77m and is accurate at all other distances...you may not be so lucky and the camera may need to be returned to factory specs by a technician.

 

[ferider]

The googles of your Summaron increase the FOV of the camera viewfinder by factor 1.4, and conversely reduce the min. lens focus distance by the same factor - this is basic trigonometry and has nothing to do with your camera.

And yes, easy to adjust the M3 min focus to 0.7m. This is not done by bending the actual RF arm in the camera, but the "tail" of the arm that limits the extension of the RF roller moving out of the camera on close focus. If important for you, you can have an authorized Leica technician do it.

 

[Gabriel M.A.]

I am really curious to know the story behind this issue and whether there is accurate technical information about it.

It is as much of an issue as black and white film not recording color or Canon or Nikon LTM lenses not focusing closer than 0.9 meters being an issue: when the M3 was introduced, all Leica lenses (as well as most if not virtually all of the rangefinder lenses of that era, Canon's and Nikon's included) had a minimum focusing distance of about 0.9 or 1 meter. Lenses with a closer focusing distance came out later.

 

[WJJ3]

The googles of your Summaron increase the FOV of the camera viewfinder by factor 1.4, and conversely reduce the min. lens focus distance by the same factor - this is basic trigonometry

Thanks for your information! What do you mean that the goggles reduce the the focus distance by a factor of 1.4? Sorry, Im not very good at math...wouldn't that mean that it would reduce the infinity focus too? can you give me the the formula for basic trig that you mentioned?

 

[WJJ3]

It is as much of an issue as black and white film not recording color or Canon or Nikon LTM lenses not focusing closer than 0.9 meters being an issue: when the M3 was introduced, all Leica lenses (as well as most if not virtually all of the rangefinder lenses of that era, Canon's and Nikon's included) had a minimum focusing distance of about 0.9 or 1 meter. Lenses with a closer focusing distance came out later.

your response didnt help me at all

 

[WJJ3]

The rangefinder focusing mechanism (the little wheel inside the camera) on the M3 can indeed be bent to focus below the standard 1m minimum distance, but bending it can also throw off the focus at other distances making it only accurate at the new minimum distance. According to some technicians and other with more knowledge than I, this is true of some cameras but not all—for instance I bent my focusing mechanism and it now focuses to ~.77m and is accurate at all other distances...you may not be so lucky and the camera may need to be returned to factory specs by a technician.

arent you just repeating some hearsay that I already found by googling?

 

[mfunnell]

your response didnt help me at all

You come seeking help, and decide that being snotty is a useful way of encouraging that? An interesting approach.

Which you seem quite happy to continue:

arent you just repeating some hearsay that I already found by googling?

If you were better at googling, yourself, you might have noticed that one of those you disparaged has given you the answer you claim to seek:

when the M3 was introduced, all Leica lenses (as well as most if not virtually all of the rangefinder lenses of that era, Canon's and Nikon's included) had a minimum focusing distance of about 0.9 or 1 meter. Lenses with a closer focusing distance came out later.

The M3 was the first Leica M-mount camera. The preceeding Leica Thread Mount system had lenses which focused no closer than 0.9 meters. Those lenses could be used on an M3 using an adapter, or new lenses designed for the M-mount could be used. Those new lenses introduced for the M-mount also had a minimum focusing distance of 0.9 meters or greater.

Are you getting this yet? No Leica rangefinder lenses produced before the M3 was developed focused closer than 0.9 meters. So the M3 did not need to focus any more closely than 0.9 meters to retain compatibility (via adapter) with those lenses. The new M-mount lenses designed to work on the M3 (the only M-mount camera then-currently in existence) were designed to focus no closer than earlier LTM lenses.

At some later time, Leica decided to make lenses which would focus at closer distances. They introduced those lenses, and they introduced cameras with lens mounts designed to focus those lenses at closer distances.

They even offered modifications so that M3s designed, built and sold before they produced such lenses could take advantage of the closer focus available with the newer lenses. (And they made sure that those later lenses would work with unmodified M3s at the M3's closest focusing distance and longer.)

They could not, however, no matter how magical the Leica name, snap their fingers and make all the M3 cameras manufactured without provision for close focusing suddenly focus more closely, without actual (non-finger-snapping) modification.

I'm not sure how to make that any more clear. I'll wait for you to correct me, from your position of vastly superior knowledge, manners and attitude.

...Mike

 

[philipus]

Ok let's pull down on the emotions a bit, shall we. Leica is a steep learning curve 🙂 I've fairly recently experienced that myself.

nottoohairy - lots of people who frequent this forum and others offer what seems like extraneous information but which on inspection is relevant. That's what the fora are about, sharing knowledge. Just be a bit patient 🙂

Anyway, have a look at the really useful wiki over at L Camera Forum (here). There's loads of really useful info there about virtually every Leica camera and lens ever made.

Cheers and happy shooting
Philip

 

[WJJ3]

OK, well thanks to ALL for taking the time to reply so far. I didn't mean to come across as 'snotty', I guess I just didn't see the point of the extraneous information that didn't do anything to address the question I posted. What I was really hoping is if ferider can explain what seemed like the answer to my question...

happy shooting!

 

[WJJ3]

You come seeking help, and decide that being snotty is a useful way of encouraging that? An interesting approach.

Which you seem quite happy to continue:
If you were better at googling, yourself, you might have noticed that one of those you disparaged has given you the answer you claim to seek:


The M3 was the first Leica M-mount camera. The preceeding Leica Thread Mount system had lenses which focused no closer than 0.9 meters. Those lenses could be used on an M3 using an adapter, or new lenses designed for the M-mount could be used. Those new lenses introduced for the M-mount also had a minimum focusing distance of 0.9 meters or greater.

Are you getting this yet? No Leica rangefinder lenses produced before the M3 was developed focused closer than 0.9 meters. So the M3 did not need to focus any more closely than 0.9 meters to retain compatibility (via adapter) with those lenses. The new M-mount lenses designed to work on the M3 (the only M-mount camera then-currently in existence) were designed to focus no closer than earlier LTM lenses.

At some later time, Leica decided to make lenses which would focus at closer distances. They introduced those lenses, and they introduced cameras with lens mounts designed to focus those lenses at closer distances.

They even offered modifications so that M3s designed, built and sold before they produced such lenses could take advantage of the closer focus available with the newer lenses. (And they made sure that those later lenses would work with unmodified M3s at the M3's closest focusing distance and longer.)

They could not, however, no matter how magical the Leica name, snap their fingers and make all the M3 cameras manufactured without provision for close focusing suddenly focus more closely, without actual (non-finger-snapping) modification.

I'm not sure how to make that any more clear. I'll wait for you to correct me, from your position of vastly superior knowledge, manners and attitude.

...Mike

Hi, not trying to be snotty again, but that is not the answer to my question. Maybe I didn't make it clear enough; I will try to rephrase it.

My M3 focuses my goggled 35mm lens accurately down to about 65cm, but it wouldn't focus a newer 50mm lens closer than about 90cm. Im wondering why this is, and if there is any accurate technical information about it?

Thanks in advance to anyone who can help me!

 

[mfunnell]

My M3 focuses my goggled 35mm lens accurately down to about 65cm, but it wouldn't focus a newer 50mm lens closer than about 90cm. Im wondering why this is, and if there is any accurate technical information about it?

I don't have a technical reference for that. My understanding is that the "eyes" ("goggles", "spectacles", whatever) had a prism-and-lens arrangement designed to work with a different focus helical on the lens mount to correctly map 64cm:90cm (roughly) at the close end through to infinity:infinity at the long end. Which is why the lens doesn't allow the right focus info to show in the viewfinder if the "eyes" are removed without replacing the helical.

But that's just my understanding. I can't be sure of it, and can direct you to no references.

You might want to ask Roger Hicks, who regularly posts here and quite literally wrote the book on rangefinder cameras ("The Rangefinder Book", by Roger Hicks) what his understanding is. He probably can provide you with references or at least direct you towards them.

He moderates/"owns" a separate forum here at RFF:

http://www.rangefinderforum.com/forums/forumdisplay.php?f=141

If you posted your question, or a reference to this thread, over there I'm sure you'd get his attention whenever he next checks in at RFF.

...Mike

 

[philipus]

My M3 focuses my goggled 35mm lens accurately down to about 65cm, but it wouldn't focus a newer 50mm lens closer than about 90cm. Im wondering why this is, and if there is any accurate technical information about it?

Thanks in advance to anyone who can help me!

I asked a similar question over at L-Camera-Forum (I hope it is ok that I link to that since I started the thread over there). Apparently, the 1m limit has to do with the accuracy of the RF mechanism of the M3 (see Jaap's reply and Lars's in the thread I linked to). While a 0.7m lens on an M3, like the Summilux 50 asph, naturally could be focused in the range 1m-0.7m the RF wouldn't show it so one would have to guess the distance (which certainly becomes tricky when shooting the 50 asph wide open...).

At the time I was using a pre-asph 50 Summilux III in LTM mount, which has a minimum limit of 1m as opposed to the bayonet mount versions (I still have this lens but will sell it), but was considering buying a 50 asph. So I asked the question because I didn't at the time have my M6TTL.

I did eventually buy a 50 asph and it focuses to 0.7 on my M6TTL (which, thus, has a different RF than the M3). I don't think this lens would go closer than 0.9-1m on my M3 (but I would have to check when I'm home from work) because I haven't had the M3's roller adjusted.

Cheers
philip

 

[WJJ3]

Thanks for your thoughtful replies!

 

[ferider]

What I was really hoping is if ferider can explain what seemed like the answer to my question...

Let me try:

The RF cam of your Leica M3 moves back and forth by the same amount as a 50mm lens changes length with focus changes (actually 51.6mm - the Leica "RF standard"). Any other lens has to "translate" focus movement to RF movement via a second helix. So does your Summaron.

For your Summaron,, because of the googles, the view is changed. Not only do the googles enlarge the field of view to that of a 35mm lens, but they also bring the focusing point closer by a proportional amount, like this:

The googl'ed Summaron at 0.65m min. focus makes the camera "think" that there is a 50mm lens at 1m focus attached.

Regarding the M3 RF adjustment, consider this picture:

The screw driver shows how to adjust infinity focus (you didn't ask, but that's why I originally made this picture ...).

The blue arrow points to the part of the RF arm that limits close focus. This needs to be bent backwards to decrease minimum focus of the camera.

Does that help ?

Roland.

 

[WJJ3]

Hey thanks for that! the figure makes it clearer for sure.

So as I understand it, the M3 won't focus any lens closer than about 90cm, except those 35mm lenses with the viewfinder adapter.

If the viewfinder adapter tricks the rangefinder into thinking that 65cm is actually 90cm, I wonder if you actually loose some close focus when you mount the 135mm lens with goggles?

 

[rxmd]

If the viewfinder adapter tricks the rangefinder into thinking that 65cm is actually 90cm, I wonder if you actually loose some close focus when you mount the 135mm lens with goggles?

Since the goggled Elmarit 135/f2,8 only focuses down to 1.5m anyway, this is not a problem 😎

 

[kokoshawnuff]

arent you just repeating some hearsay that I already found by googling?

Nope. Actual, real first-hand experience, and conversations with two different leica techs, make me believe that it is more than googled 'hearsay'.

But then again many have been burned by a dependency upon info discovered online without any actual first hand experience. Paranoia would make me doubt many things online if I didn't have the ability to discover anything on my own.