Circle of Confusion

[christoph]

Some one know the size of Circle of Confusion of the differnet film format:
S8 , 16mm, S16, 35 ???

For S16 I know that, if you are intending to blow up to 35, you should work to 1/2000 inch.

if you care to do a google search you'll find all sorts of numbers.. however, the more reliable will probly fall into this area:

The American Cinematographer Manual provides depth of field tables for 35mm and 16mm formats. The tables are based on the simplified depth of field equations. The DOFMaster programs can be used in place of the tables if the appropriate circle of confusion is used for a particular film format.

The 1986 edition of the manual recommends 0.025 mm (0.001 inch) for the circle of confusion for 35mm format. 0.015 mm (0.0006 inch) is recommended for 16mm format. Earlier editions recommended somewhat larger circles of confusion.

++ christoph ++

[calgodot]

Lenny Lipton sez (on page 163 of his classic Independent Filmmaking):

"The size of the circle of confusion that we can accept is dependent on how we view the projected film. ...the choice of an acceptable maximum diameter for the circle of confusion is based upon the projected film as it is viewed by some hypothetical viewer, a certain distance from a screen of a certain size. The choice that has been made for the circle of confusion for 16mm is 0.001 inch, and for 8mm 0.0005 inch. The circle of confusion for super 8-single 8 would be very nearly that of 8mm, actually 0.00065 inch."

He goes on to say that this is operating on the assumption of "essentially aberrationless lenses" and the assumption that "the size of the grain of the film is smaller than the circle of confusion." "With some 8mm or super 8-single 8 films," Lipton adds. "the grain size may approach the size of the circle of confusion, and therefore may set a limit on the actual depth of field."

[kandinsky]

Thank for all info

K