Why, is there some CAPITAL LETTERS, after some people's name in the movies.?

Question

So, I usually see them in Custom design, or director of photography.

Usually, something like this.

John Crapper, ASC.

What do this abreviations means?

Answer 1

Those are the initials of organizations that they belong to.   Many of them are required to have membership in those org.'s in order to work in the industry.

Answer 2

ASC  means American Society of Cinematographers.  Those initials after "John Crapper's" name means he is a member.  

Answer 3

Those are the various groups that have recognized the artists as one of theirs.  In Engineering, you can take a test and become a Professional Engineer (PE), but artists are recognized by their work, not a test.  So when The American Society of Cameramen (ASC) regonize a photographer, then he can use ASC after his name.  There's also BSC British Society of Cameramen.

Answer 4

Besides ASC, you also see BSC (British ...) and CSC (Canadian . . .)

Answer 5

It's an organization that the person may belong to.

Just like the name you gave as an example...

ASC stands for American Society of Cinematographers.