Re: [Leica] Goggles modification for 21mm/24mm M lenses

[TTAbrahams@aol.com]

In a message dated 8/9/99 10:45:33 PM Pacific Daylight Time, 
phong@doan-ltd.com writes:

<< Subj:     [Leica] Goggles modification for 21mm/24mm M lenses
 Date:  8/9/99 10:45:33 PM Pacific Daylight Time
 From:  phong@doan-ltd.com (phong)
 Sender:    owner-leica-users@mejac.palo-alto.ca.us
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 To:    leica-users@mejac.palo-alto.ca.us 
 Tom A. & other LUGers, 
 I have been thinking wider for my M cameras, and been wondering
 about external viewfinders, and how to avoid them.
 What 21mm/24mm Leica lenses can be modified with goggles, 
 to be used with the M6 (classic or HM).  How well do they work ?
 I assume the 28mm frame lines are used;  how exact is the
 framing ?  also, RF focusing, and metering can be made to
 work as with other lenses ?
 Any suggestions, comments, gotchas, lens recommendations ?
 Perhaps just forget it altogether, and use R cameras and lenses
 for wider than 28mm ? 
 Thanks in advance
  >>
Phong,
 The "goggled" 21mm lens is one of my designs and it was born out of the 
frustrations of losing finders and shots when I had to shift between focus 
and framing. The 24 could conceivably be modified although I haven't done 
that yet. The "goggled" 21 works very well, with certain caveats. Due to the 
addition of more glass in the viewfinder, the goggles, it loses some of its 
brilliance and the close focussing becomes less precise. It is possible to 
recalibrate the lens, but I haven't done it. Most of my wide-angle shooting 
is either street shooting and the distance is 6 feet or more and then the 
close focus is not critical, or it is architectural shooting and the lens is 
used at infinity or close to that.  With the HM you have a problem, as there 
is no 28 frame to use for reference. I usually put the goggled 21 on a M2 and 
tape over the frame-illuminating window so that no framelines show and you 
have a clear finder with just the focussing patch. It is pretty close to 21 
that way and the error is on the optimistic side, you get a fraction more 
than you see, which is better than the other way around - you can always 
crop, but adding to the image is tough.
 It is possible to use the 24 without any finder on the M6 or M4P, just use 
everything you see, all the way out to the edge of the viewfinder and it 
works fine (the trick of taping the frame illumination window works well in 
this instance too). The M-camera was never designed for ultra precise 
framing, for that you need an old Nikon F with the prism, only camera that I 
trusted in giving me 100% of what you saw. If you need the close focus range 
(0,4-1,5 meter) and do most of your shooting in that range, I would not 
recommend the conversion, but if you are shooting action and street "style", 
it is a major advantage. You can convert the 21/3,4 or the 21/2,8's, the 
21/2,8 Asph is an awesome optic, but I do retain a soft spot for the 21/3,4, 
it is smaller and more compact and it has a quality all its own. I have both 
and occasionally I end up using the 21/2,8 Asph on a M6 because I need the 
metering facility, but I mainly use the 21/3,4 because its small size and 
then on a M2 as it will block the meter on the M6.
All the best,
Tom A