The factor on bellows compression is the type of material used. This ranged
from leather, neoprene rubber, early naugahyde, vinyl, rayon and nylon.
The maximum lenth and compression are as new.  The max lenth on an
old leather bellows will shrink as much as 6 inches!!
The compression goes up also.

   8x10                        Max Lenth        Max Compression
1923-50 Leather                   31in                         5in
1950-52 Neoprene               31in                          4in
1950-52Naugahyde              31in                          4in
1952-68 Naugahyde             31in                         3.5in
1968-83 Rayon                    31in                        3.5in
1979-88 Nylon                     31in                          3in

From the mid 60s to the mid 80s a fabric from Uniroyal rubber was occasionally used. If you have one you know it. It simply does not wear out. Why didn't  Deardorff  use this all the time? As near as I can tell Deardorff got this fabric on the surplus market. if it was available they used it.

      5x7 OS
1926-50 leather                    24in                           3in
1950-52 Neoprene                24in                          3in
1950-52Naugahyde               24in                          3in
 4x5 Spec / 5x7 View
1952-68 Naugahyde              24in                          3in
1968-83 Rayon                     24in                       2.75in
1979-88 Nylon                     24in                        2.50in

                                            8x10                       4x5 / 5x7
Rear swing       Plus Minus  15 deg                      15 deg
Front swing      Plus Minus 15 deg                      15 deg
Front rise                             5 1/2 in                    3 1/2 in

Main Page