Mysterious Leica tube... what have I got here?

Dear rec.photo.equipment.35mm gurus, :-)

I got a nice, not quite minty but very good looking, Leica extension
tube off Ebay recently. Problem is, I don't exactly know what it is.
:-)
(Before you ask what got into me, I got a very nice looking piece of
original Leica stuff for 25 dollars, while my local pro photo store
has the same tube in the occasion department for about 6 times that
much. So I figured I couldn't go that much wrong.)

This extension tube has the text 'LEITZ WETZLAR GERMANY' on the barrel
in white, and the figure '100' in yellow. It fits the R-mount on my
Leicaflex body. The tube has a conical ring at the front that sits
around the aperture ring of the lens you put on it and prevents you
from (presumably accidentally) rotating it.

Which lens is this tube designed to accommodate?

The tube will take (with some difficulty) my Summicron-R 50mm lens. I
can also put my Elmarit-R 90 and 180mm lenses on it but it takes much
more force (accompanies with the sound of grinding aluminium) than I
am comfortable with, so I tried that only once.
However, when I put my 50mm lens on it, the aperture ring on that lens
rotates while you twist-and-lock the lens onto the tube, from the
minimum aperture (f/16) in the direction of the maximum aperture (f/2)
and the tube's ring around the aperture ring on the lens prevents you
from correcting this.
On the other hand, the tube does reduce the minimum focussing distance
of the 50mm lens so that a postage stamp fills the frame. If
mounting/dismounting were smoother and the aperture ring would behave,
I'd actually be able to get some good use out of this thing... But how
to accomplish that?

Any response appreaciated!

Regards,
Frank

In article ,
Frank van Wensveen wrote:
Dear rec.photo.equipment.35mm gurus, :-)

I got a nice, not quite minty but very good looking, Leica extension
tube off Ebay recently. Problem is, I don't exactly know what it is.
:-)
(Before you ask what got into me, I got a very nice looking piece of
original Leica stuff for 25 dollars, while my local pro photo store
has the same tube in the occasion department for about 6 times that
much. So I figured I couldn't go that much wrong.)

This extension tube has the text 'LEITZ WETZLAR GERMANY' on the barrel
in white, and the figure '100' in yellow. It fits the R-mount on my
Leicaflex body. The tube has a conical ring at the front that sits
around the aperture ring of the lens you put on it and prevents you
from (presumably accidentally) rotating it.

Which lens is this tube designed to accommodate?

It might be the 1:1 extensions tube for the 100mm f/4 macro elmar.


The tube will take (with some difficulty) my Summicron-R 50mm lens. I
can also put my Elmarit-R 90 and 180mm lenses on it but it takes much
more force (accompanies with the sound of grinding aluminium) than I
am comfortable with, so I tried that only once.
However, when I put my 50mm lens on it, the aperture ring on that lens
rotates while you twist-and-lock the lens onto the tube, from the
minimum aperture (f/16) in the direction of the maximum aperture (f/2)
and the tube's ring around the aperture ring on the lens prevents you
from correcting this.
On the other hand, the tube does reduce the minimum focussing distance
of the 50mm lens so that a postage stamp fills the frame. If
mounting/dismounting were smoother and the aperture ring would behave,
I'd actually be able to get some good use out of this thing... But how
to accomplish that?

Any response appreaciated!

Regards,
Frank

In article ,
Frank van Wensveen wrote:
Dear rec.photo.equipment.35mm gurus, :-)

I got a nice, not quite minty but very good looking, Leica extension
tube off Ebay recently. Problem is, I don't exactly know what it is.
:-)
(Before you ask what got into me, I got a very nice looking piece of
original Leica stuff for 25 dollars, while my local pro photo store
has the same tube in the occasion department for about 6 times that
much. So I figured I couldn't go that much wrong.)

This extension tube has the text 'LEITZ WETZLAR GERMANY' on the barrel
in white, and the figure '100' in yellow. It fits the R-mount on my
Leicaflex body. The tube has a conical ring at the front that sits
around the aperture ring of the lens you put on it and prevents you
from (presumably accidentally) rotating it.

Which lens is this tube designed to accommodate?

It might be the 1:1 extensions tube for the 100mm f/4 macro elmar.


The tube will take (with some difficulty) my Summicron-R 50mm lens. I
can also put my Elmarit-R 90 and 180mm lenses on it but it takes much
more force (accompanies with the sound of grinding aluminium) than I
am comfortable with, so I tried that only once.
However, when I put my 50mm lens on it, the aperture ring on that lens
rotates while you twist-and-lock the lens onto the tube, from the
minimum aperture (f/16) in the direction of the maximum aperture (f/2)
and the tube's ring around the aperture ring on the lens prevents you
from correcting this.
On the other hand, the tube does reduce the minimum focussing distance
of the 50mm lens so that a postage stamp fills the frame. If
mounting/dismounting were smoother and the aperture ring would behave,
I'd actually be able to get some good use out of this thing... But how
to accomplish that?

Any response appreaciated!

Regards,
Frank