Re: COCs

[Eric Goldstein <egoldste@xxxxxx>]

Greg Erker wrote:

>   Here's something from dejanews that discusses
> why MF has less DOF than 35mm and says why
> you use different COCs for them.


An interesting and informative discussion, but lacking in the one
critical aspect of this discussion of major consequence: viewing.

It is true that DOF will remain contant for various formats using
"normal" lenses IF viewing conditions remain equal. That is a big IF,
and I think in the case of our stereo photography we place higher
demands on viewing than a normal "ortho" view of a gallary print.

While a 0.8 mm COC might be acceptable for the Ricoh factory assuming
standard viewing factors , they are likely inadequate for stereos higher
orders of magnification and/or closer viewing distances, not to mention
the tendency for stereopsis to demand greater DOF/smaller COC than might
be tolerable with a mono view.

Rollei BTW specified 0.5ish for MF I think and the 35mm standard is
about 0.33 mm.


Eric G.