Quote Originally Posted by Ian C View Post

On page 17 of the Kodak Retina 1b manual (Part 1 of the PDF), the last example gives a 22-foot hyperfocal distance at f/8. You have to read it carefully to see that this is the actual focusing distance being used (“The depth of field then extends from 11 feet to infinity.”)

This leads to a circle of confusion diameter of 0.047mm.

http://www.cameramanuals.org/kodak_p..._retina_ib.pdf
Yep! Those are the values that the DOF field scale shows. So it is apparent that manufacturers were using a larger CoC back then, compared to the modern "standard" of .03mm. I would assume this was related to the grain size and sharpness of the film that was available at the time.

This appears to have been the standard back then. I've checked a couple of my Oly 35's from the 1950's, and they show the same scales as the Kodak and Voightlander.

Thanks for the input, guys!