Re: Noctilux/flange to film plane

[Edward Meyers <aghalide@panix.com>]

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On Sat, 13 Sep 1997, Dan Cardish wrote:

> At 12:34 AM 13-09-97 -0400, Marvin Moss wrote:
> >In a message dated 97-09-12 23:28:03 EDT, you write:
> >
> >Joe B. (etal
> >
> >   A little known problem sometime arises with wide apertures & the resulting
> > shallow depth of focus due to the flange to film plane distance being off
> >more
> > than 1/10 of a mm (that's only 1/250 of an inch).  I think a heavy squeezing
> > of a zinc body can cause this & for critical work, you can test the d.f.
> >your-
> > self with just a few test exposures or have a technician use a depth gauge
> >if
> > you focus is off even slightly.  I have taken c.u. pix at f:1.0 where one
> >eye 
> > was in focus & the other out, so we are talking about a very close
> >tolerance.
> 
> Years ago I owned a Minolta SRT-101 that came with a 58mm/1.2 lens (Still
> have the lens, body was stolen).  There was a story circulating in the
> photo mags in the '60s that Minolta individually matched up the 1.2 lenses
> with camera bodies when bought as a unit.  Maybe this has to do with
> overcoming variations in film plane to lens flange distances.  I do know
> the the lens was very good.
> 
> Dan C.
> 
Yep...I remember that during tests with some SLRs at Popular Photography
magazine (1970s th 86) some cameras changed focus when squeezed a
bit. I don't think it was reported. Might make an interesting auto-focus
mechanism...H'mm. Isn't that what Yashic-Contax does??? Ed Meyers