Re: Fwd: 35mm vs 2 1/4, again, my real world experience

[cmiller@berkshire.net (Curt Miller)]

Hi group -

Duane wrote in part:
> But for the pictures I really cared about: landscapes.  Depth of field 
>and subject movement were two continual problems that made for less 
>than desired overall sharpness. In those instances where I shot both,  
>I have great 35mm negs and zip 2 1/4.  Actually, sharpness may not be 
>the best term.  As it was often lack of depth of field and subject 
>movement that was giving the unsatisfactory results, not lack of 
>resolution.  I rarely print personal BW stuff larger than  11"x 14" and 
>from viewing distances of 2 feet,  Grain is not a factor.   


For 65 percent of my work I use my Leica RF (street and landscapes).  For 25
percent, my Hasselblad (landscapes and events).  For the remaining 10
percent I use my Nikon F4 (love that autofocus for many things).

I'm responding to the recurrent topic of DOF in the medium format.  To the
extent it seems off-topic of Leica, I apologize, however, optical theory is
important to all of us.

There is no difference in apparent DOF in an 11X14 print between an image
made with a 50mm Leica lens at, say, f/8 and one made with an 80mm
Hasselblad lens at f/8.  I know this may raise some eyebrows.  There IS a
difference, however, if you enlarge the Hasselblad image by the same factor
of 11 (giving a 20X24 enlargement) and view the picture from the same
distance as the 11X14.

Lens manufacturers have standardized the DOF for 8X10 images viewed from a
certain distance.  You certainly will have larger circles of confusion ON
THE NEGATIVE with the MF at any given aperture but since you don't enlarge
it as much as the 35, the apparent DOF is the same.  Grain will be less with
the MF.

If there are any doubters among us, just get out a 50 Leica lens and an 80
Hassy lens (or a 35 Leica and a 50 Hassy).  See what the DOF scales show for
f/8 (or F/whatever you choose).

Think this is sort of a common misperception about applied optical theory.

Regards,

Curt