SMPE Standards 1928

           

           

 

This booklet is the SMPE Standards, Approved April 9 1928. 

Some of the interesting facts are:

1. Two types of positive perforation are recognised as standard.  One is the Kodak Standard (KS) perforation.  The other one is somewhat similar to the Bell Howell (BH) perforation but without the sharp corners.

2. In the section on Take-up Sprockets it states that the pitch is set to the maximum shrinkage (1.5%) occurring on films of commercially useful condition.

3. It  says in the section on Feed Sprockets that newly processed film shrinks by 0.13%.  The pitch standard is 0.1870 which gives a value for processed film as 0.1867.  When short pitch stock was introduced the pitch was set at 0.1866.

4. Aperture size: The existing ratio of 3 to 4 between height and width of picture should be retained when introducing any new size of film.

5.The standard  projection speed is given as 80 ft a minute +/- 5 feet per minute giving a projection speed of 21.3 fps

6. The camera cranking speed is set at 60 ft per minute +/- 5 ft per minute a speed of 16 fps.