Re: Different Formats for Different Countries -- Variable Density

Tony Clarke wrote (in part):

>     Someone on a forum - possibly not this one - confused me recently by
> saying that "full plate" was 8 x 6 inches and all else was a division of
> that. Sounds like the confusion over book binding classifications based
on a
> broadsheet being 15" x 20" except when it wasn't. I thought "full plate"
was
> 10 x 8 inches, as the original master size for photos and respected to
this
> day in paper sizes. Am I wrong?
> 
I do not know if there is any such thing as "full plate" in photography.
Back in Daguerreotype days, the images were made on a sensitized sheet of
copper plated on one side with silver and then sensitized by the user.
These
plates had standard sizes:

Full Plate:      6½ by 8½ inches
Half Plate:      4¼ by 5½ inches
Quarter Plate:   3¼ by 4¼ inches
Sixth Plate:     2¾ by 3¼ inches (a.k.a. "medium plate")
Ninth Plate:     2  by 2½ inches
Sixteenth Plate: 1 3/8 by 1 5/8 inches

Now ordinary printing paper, in USA, came from the size of the frame
commonly used for making paper by hand that turned out 17 by 22 inch
sheets
after the deckle edge was trimmed off. This was about the largest they
could
make sheets for a long time. These where cut in half both ways making 8½
by
11 sheets as standard for printing (and later, typewriting).

-- 
  .~.  Jean-David Beyer          Registered Linux User 85642.
  /V\  PGP-Key: 9A2FC99A         Registered Machine   241939.
 /( )\ Shrewsbury, New Jersey    http://counter.li.org
 ^^-^^ 18:05:01 up 3 days, 19:32, 3 users, load average: 4.39, 4.20, 4.12