[LargeFormat] 58mm S.Angulon

[Richard Knoppow]

----- Original Message -----
From: "Richard Knoppow" <dickburk@ix.netcom.com>
To: <largeformat@f32.net>
Sent: Saturday, February 15, 2003 12:06 PM
Subject: Re: [LargeFormat] 58mm S.Angulon


>
> ----- Original Message -----
> From: "philip.lambert" <philip.lambert@ntlworld.com>
> To: <largeformat@f32.net>
> Sent: Saturday, February 15, 2003 3:09 AM
> Subject: Re: [LargeFormat] 58mm S.Angulon
>
>
> > Thanks Richard, what a lot you know or know where to
look
> for it!   Did your
> > source give you the flange to film distance at infinity?
> That's all I need
> > now (as it determines bellows bind up or not). I was
> intending to use the
> > lens on 8 on 120 or 10 on. Incidentally when you give
> 152mm as  the diagonal
> > of 5x4 inches did you measure it?  I had thought 162mm
was
> the calculated
> > diagonal of 5x4 inches.  Philip
> >
  Whoops, missed the part about the diagonal.
 162mm the diagonal for 4x5 inches and is correct for glass
plates. However, sheet film in 4x5 and larger sizes, is
smaller than the "nominal" size by something like 3/16ths
inch in both directions. The masking from the film rails in
the holder further reduce the image size, so the diagonal of
the image is about 152mm (6"). Holder masking varies to the
dimensions are not exact.
  I think the reason for the smaller size is that when sheet
film was introduced the available holders were for glass
plates. The smaller size of the film is to accomodate the
"sheaths" or sheet film adaptors. The smaller size is
certainly true for 4x5, 5x7, and 8x10. I don't know if its
so for European sizes or for larger sizes, although it
probably is.
  In the USA sheet film, including Kodachrome, was made in
sizes up to 16x20.
  Smaller sizes of sheet film are the stated size, although
again I can't be sure of the millimeter sizes for European
plate back folders.
  There is an ANSI standard for this somewhere. For some
reason most of the charts showing viewing angle and coverage
of lenses do not take this into account.

---
Richard Knoppow
Los Angeles, CA, USA
dickburk@ix.netcom.com