Leica IIIf viewfinder question

[jcb4718]

Does the Voigtlander 50mm f2.5 LTM partially block the IIIf viewfinder? If so, by how much? I have several of LTM lenses and know roughly what combination of diameter and (flange to front) length are likely to be intrusive so if a fellow member could let me know these dimensions, I'd be grateful.

 

[Bill Clark]

You can find dimensions for a few of the screw mount lenses here:

http://www.l-camera-forum.com/leica-wiki.en/index.php/Main_Page

Info on III f:

http://www.kenrockwell.com/leica/screw-mount/iiif.htm

With mine I do see the edge of the 50 Summicron in the viewfinder but with the 35 Summaron I do not.

For your particular lens I would recommend sending an email to Mr. Steve Gandy who owns this forum.

 

[traveler_101]

Yes, it will block it a tiny bit.
The specs for the CV Color Skopar 50mm f/2.5 are

Length 1.3" (33.6mm)
Maximum Diameter 1.95" (49.6mm)
Weight 7.3 oz (208g)

This according to B&H, which is a pretty reliable outfit . . .

The CV Color Skopar 35mm f/2.5 Classic, which I own, seems to have exactly the same dimensions, by my measurement.

So I put the 35/2.5 on my IIIf. Without the hood it is BARELY noticeable at the lower right fringe of the viewfinder. With the hood you will notice it; it occupies the lower right side from approximately halfway across the lower perimeter and it extends a fraction into the viewfinder. What does it occupy - 5% of the viewfinder - perhaps?
Not much.

My postwar Leitz 5cm f/3.5 "Elmar" does not block the viewfinder. It is actually smaller than the Skopar, though some would want to shoot it with a hood which would be noticeable.

 

[oltimer]

You can find dimensions for a few of the screw mount lenses here:

http://www.l-camera-forum.com/leica-wiki.en/index.php/Main_Page

Info on III f:

http://www.kenrockwell.com/leica/screw-mount/iiif.htm

With mine I do see the edge of the 50 Summicron in the viewfinder but with the 35 Summaron I do not.

For your particular lens I would recommend sending an email to Mr. Steve Gandy who owns this forum.

Bill
With my IIIF Leica/Midland in the 684XXX range, the 35 Summaron f2.8 tabbed lens (1962) does show up bottom right. With the factory hood for that lens, there is a real problem.

 

[jcb4718]

Thanks for all the replies! I have a CV 21mm f4. Of course I don't use the IIIf viewfinder with this lens but I do have its dimensions (length (flange to front) 29.5mm; diameter (mini hood on front) 43.5mm). I attach the view through the IIIf viewfinder. For me, its usable but getting near the limit. I have a Canon 50mm f3.5 collapsible (length 35mm; diameter 35mm) and a Super Rokkor 45mm f2.8 (length 18mm; diameter 45mm) and neither of these lenses significantly intrude into the viewfinder (I can just about see the lenses). The OD quoted by B&H (49.6mm) is quite large. I wonder if this is the excribed circle, including the tab? I see B&H recommend a M39 filter for the 50mm f2.5 (same as my 21mm f4) so its reasonable to assume the front diameter is the same (i.e. 43.5mm); its difficult to imagine the 50mm lens is shorter than the 21mm lens, in fact they look about the same, so I guess the 50mm lens would intrude into the viewfinder a little more than the 21mm lens. Again, thanks for all the replies.

 

[D.O'K.]

I put the CV 50mm 2.5 on my lllf--it intrudes very little into the field of view. Like your picture of the 21, it gets about halfway across the horizontal but only about 8% up the vertical plane. This is without any filter but with the standard/integral hood, and at infinity. As one focusses closer it intrudes slightly more into the view as the lens extends, but not significantly.

Sorry I'm unable to post a photo to show all this!

The reality is that the intrusion is too trivial to worry about.

Regards,
D.

 

[jcb4718]

Thanks for that D.O'K. I think your comment has conclusively answered my question. The blockage is about the same as my CV 21mm. It's the same hood size and, although the CV 50mm may be a little longer, a little increase in length is much less important than the same increase in hood diameter. Once again, thank you all for your replies.