15x12 inch vs 30x40cm Film Question

[rknewcomb]

Ok, The older Bristish plate cameras used 15x12 inch film (plates).
The old European plate cameras used 30x40cm.
40cm = 15.748 inch
15 inch = 38.1 cm
So, are these really two different size cameras?
The little bit that I have seen about the modern availability of film in this size is called 30x40cm.
So, if someone were going to have modern holders made to use in these cameras, which size should they take or are they actually the same...?
thanks for the help.
Robert Newcomb

 

[argus]

Hello RObert,

metric and imperial measures are NOT meant to be the same. This is also true for film formats in both systems.
You will have to decide if you are going to use 30x40cm or 12x15" sheet film.

Kind regards,
Geert

 

[Ole]

The sizes really are different.

One problem is that 30x40cm film has a tendency to be 12x16", which is ever-so-slightly too large. Same with 24x30cm / 9.5x12" - while the "imperial" size is 10x12".