Re: [Leica] DOF notches

["Joe Stephenson" <joeleica@email.msn.com>]

Nigel,
It's quite simple. The old-timers simply meorized the depth of field table
for each lens they used. It's much simpler than having to squint at the
markings on the lens.
SIncerely,
Joe Stephenson
- -----Original Message-----
From: N. B. Watson <nbwatson@juno.com>
To: leica-users@mejac.palo-alto.ca.us <leica-users@mejac.palo-alto.ca.us>
Date: Saturday, October 10, 1998 1:22 PM
Subject: Re: [Leica] DOF notches

>The DOF marks (later M3 finders, all M2 finders) indicate the DOF of a
>50mm lens at f5.6 (narrow notch) and f16 (wide notch).  With the rfdr
>pre-focussed on any given point, simply place the rdfr patch over any
>other subject nearer or farther away without re-focussing the lens.
>Separation of the two rdfr images by a margin falling within the width of
>the notch (whichever is appropriate to your chosen f-stop which has to be
>5.6 or 16) indicates that this subject would be with the "plane of
>acceptible un-sharpness" we call DOF.  Again, it works accurately only
>for those two apertures and only with a 50mm lens.  As clever as it is,
>the DOF scales on the lenses have always been my guage of choice, even
>with the M2 and "notches".  BTW, can anyone out there elighten me as to
>how those folks who use the Contax G determine DOF?  I had the chance to
>handle one belonging to a chap I met on holiday a while back (he was a
>casual happysnapper who didn't know what DOF was) and noted straight away
>that the lenses had no DOF scales nor was there any viewfinder aid.  My
>impression was that it was less a point-and-shoot than a point-and-pray.
>Did I miss something?
>
>Regards,
>Nigel
>On Sat, 10 Oct 1998 10:59:12 -0700 (PDT) M3novie@webtv.net (Scott Green)
>writes:
>>Hey folks!  So here's a question that I've been occasionally trying to
>>figure out for some time now:  I once read somewhere that the little
>>notches in the upper and lower egdes of the M3 viewfinder are supposed
>>to be a quick DOF reference when using  a 50mm and -- what was it -- a
>>90mm lens.  I haven't quite figured out how to use 'em, though.
>>Granted, it's been a while since I last looked in there and tried.
>>Now
>>that I've written this, I'll probably go and figure it out as soon as
>>i
>>pick up the thing 8-}  So, are you supposed to look _between_ the two
>>notches' edges, or between the two notches themselves?  It runs in my
>>mind that I saw this in Brian Bower's book, but he wasn't very clear
>>on
>>exactly what they do.
>>
>>Anybody out there able to clue in a dolt?  Thanks a lot!!
>>Scott
>>
>>
>
>___________________________________________________________________
>You don't need to buy Internet access to use free Internet e-mail.
>Get completely free e-mail from Juno at http://www.juno.com
>or call Juno at (800) 654-JUNO [654-5866]