[Leica] Leica vs. 120

[LRZeitlin@aol.com]

The Leica/Hassy comparison does not properly address the small camera vs. 
large camera issue since so much of the 6x6 Hassy image is wasted when 
cropping to the 35mm format. The resulting image area is only 2.5 times that 
of the Leica. A better comparison would be between a Leica and a 6x9 cm. 
format camera, say the old Kodak Medalist. 

Both the Leica and the Medalist have the same 2x3 negative form factor. The 
Leica negative has an area of 864 sq. mm, the Medalist has 4959 sq. mm area 
and is 5.74 times larger. A 16 x 20 enlargement from the Medalist neg is 
about a 7X blowup. From the Leica neg a 16 x 20 is about a 17X blowup. To 
meet the 2 min. arc. (6 lines/mm) criterion of visual sharpness on the print, 
when viewed at 12 inches, the Leica negative image would have to retain a 
resolution of 102 lines/mm. This involves the conjoint resolution of the 
taking lens, the film, the processing, and the enlarging lens. To meet the 
same criterion, the Medalist would have to retain a resolution of 42 
lines/mm. Those of us who have used both 35mm and 6x7 or 6x9 negative sizes 
know that making a good 16x20 print from the small neg. requires a herculean 
effort while with the large size it is pretty easy. I'm not saying it can't 
be done. Obviously many photographers do it. But it takes so much less effort 
to use a larger film size and devote creative resources to the quality and 
composition of the image on the film. Or if you want a REAL challenge, use a 
Minox instead of a Leica.

 Leicas are fine cameras but using one to shoot 16 x 20 architectural photos 
is like using a tack hammer to drive a spike.

LarryZ