George Mann
Member
What do you mean be “dud”? If you mean wrong exposure, very, very few. Otherwise, a dud depends upon intent and standards. Low standards, few duds, high standards, many duds. G.B. Shaw described the ratio of successes to failures to the number of salmon who make it upstream to spawn.
We are talking about the number of perfectly exposed images.
When I shot Kodachrome with my Nikkormat, I had averaged a success rate of 85%. No amount of exposure tricks could improve upon it.
Shooting E6 with stepless electronic shutters (as well as the use of a spot meter when needed), my average success rate is as high as 97%.