"bmoag" wrote in message
. net...
What do you want to use this lens for?
A 42-44mm equivalent lens is not what many would consider a "normal" lens
on a 35mm film camera. That would be more of a "semi-wide" lens.

Not really. The traditional "normal" focal length is equal to the diagonal
of the negative, or about 43mm for a full-frame 35. So a 28mm lens on a D200
(equiv. 42mm on a 35) makes a very nice normal.

No one really knows why Barnack chose 50mm for the Leica's standard lens,
but for good or ill that became the established standard. Zeiss actually
made a 42.5mm normal lens for the Contax in the 1930s, but it never became
popular.


Lenses of this focal length were used on film P&S cameras but never really
caught on for 35m slr cameras.

But for an entirely different reason. SLRs have a minimum flange-to-film
distance in order for the mirror to have room to swing. For that reason,
while slower, physically small four-element lenses like the Zeiss Tessar
were usually 50mm, the much larger fast lenses like the Zeiss Biotar were
usually 58mm. They weren't 58mm because that was a desired focal length, but
because around 1950 or so it was hard to design a fast lens of shorter focal
length that would still give the mirror room to swing. Later on, they were
able to design 55mm and then 50mm fast lenses for SLRs. Shorter than that,
fast lenses become harder to design for an SLR, more complex and therefore
more expensive.

Neil