"register" of a 4x5 sheet film holder

[grommi]

Hello there,

I'm about to play with my first LF camera ever, a 9x12 plate camera that shall be converted for the use of regular 4x5 and 9x12 sheet film. I need to build a new back and need the exact measure from the surface of the film holder to the film surface. Must be something less than 5 mm?

Thanks a lot in advance - Reinhold

 

[E. von Hoegh]

.197" +/- .007" as per ANSI spec.

 

[grommi]

Thanks a lot, that is exactly 5 mm.

 

[Jim Jones]

According to the 1951 ASA spec sheet the "T" dimension for 4x5 holders is indeed .197 +/-.007", but that is the distance to the back of the film. The slot in which the film rides is .012". Film varies from maybe .004" to .010". Thus, the distance to the film emulsion is somewhat indefinite in ordinary film holders.