Digital BW, The Print

Tom,

> DOF is not a sensor size issue.  It's a lens issue....

I was afraid after I sent the msg that someone would come back with
this.  Sigh. I thought it was a given and didn't need to be stated,
that with smaller sensors we use shorter focal lengths for the same
effects.  My favorite lens in 6x7 was 135mm. That's about 65mm in 35
and about 15mm with the Pro-1.   It's not a linear translation
however, since, as Paul has already mentioned, that the circle of
confusion factor changes as well.  

The pro-1 lens has limitations, as do all lenses.  I've found that
it's optimum aperture, in terms of overall sharpness, corner
sharpness, lack of vignetting, etc., is around f/4.5 to 5.6  (its
range is 2.4 to 8.0).  I have also found that at f/5.6 I get greater
DOF at 15mm than I got with the 135mm/P67 at f/32, and I'm at optimum
aperture with much faster speeds.  It's wonderful.

Since I don't know the COC factor for Paul's lenses, my question to
him was not theoretical, but practical: what has been his experience
with this so far?  I hope this clarifies it.


Regards,
Clayton


Info on black and white digital printing at    
http://www.cjcom.net/digiprnarts.htm