Archived posting to the Leica Users Group, 1998/06/05

[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]

Subject: RE: [Leica] Tri-Elmar focusing
From: "Shahinian, Vahan" <shahinianv@genrad.com>
Date: Fri, 5 Jun 1998 20:35:15 +0100

It seems to me that the focus cannot change on the Tri-Elmar. The same
focus scale is used for all three focal lengths (as with an ordinary
zoom lens) and more importantly, there is only one focus cam on the lens
to interact with the camera rangefinder and this does not move when the
focal length is changed. All in all it quite a remarkable mechanical and
optical achievement. The tolerances must be extremely tight. Perhaps
that's one of the reasons that the maximum aperture is f/4.0.

I think the reason they call it a variable focal length lens rather than
a zoom is due to the fact that there are no intermediate focal length
settings.

I've used the lens for a couple months now and feel that it works quite
well. The downside is the size of the lens, particularly with a lens
shade attached. It definitely intrudes into the viewfinder field of
view.

Vahan

- -----Original Message-----

According to the experts, variable focal length lenses (as opposed to
zooms) do not hold focus between focal lengths. I believe I've seen this
stated specifically in Leica literature.

Jim


At 01:36 PM 6/3/98 +0000, you wrote:
>George Huczek wrote:
>> 
>> Does anyone know if this lens has to be refocused when focal lengths
are
>> changed?