[Leica] HiRes Photography (1)

["Erwin Puts" <imxputs@knoware.nl>]

Recently it has been opiniated that the level of  image quality that any
serious 35mm photographer would need or should care about, is that defined
by an ordinary Pentax lens from some 20 years ago. In itself any opinion is
just that: an expression of what someone believes to be true and as beliefs
are beyound the realm of proof, we need to delve somewhat deeper to get at
the core of the matter.
First of all it is very difficult and thus takes some hard work to extract
the full optical performance from a lens, and an older (pre-AF) Nikon or
Canon or Topcon lens has a lot of potential. (Pentax lenses are not a very
good example of  good optical quality). We have to note that while most
people talk about resolution of at least 200 lines/m to qualify as a good
lens, in reality we may be very happy if we can transfer 40 lines/mm form
the negative to 3 lines per mm on the print (assuming a 16 times
enlargement) with good contrast, so as to make these details visible. In my
practical experiments with HiResPhotography and Leica lenses, I am now using
that new BW film, and at first results were worthless. Then I used the
normal selection of tools (tripod, flash etc) and with my M6 and the 2/90
asph or 3.4/135 I could record more than 200 lines per mm on the negative.
The
objects were NOT the flat test charts with the funny bars, but real life
objects of three dimensional extension, like cars and models. On print
however, this level of detail was not detectible at all. So I used a special
sharpness adjustment negative from Fotowand and could finetune my V35 so as
to get 8 lines per mm on the print (16 times anlargement and visible with
the naked eye, hat is about 130 lines per mm from the negative). These
details,
while visible are quite soft and here the limits of the Focotar are reached.
The Leica lenses obviously record it on the negative and the film does
capture it easily. To extract the full potential from the lens, is not easy,
but it is fun and my next project is to transfer these results to shooting
situations that are more casual or in more demanding lighting.
Now if we would lower our demands to 30 or 40 lines per mm (that is to about
15% of the potential of current Leica lenses and about the level of an
ordinary Pentax lens), it is evident, that we can relax all our parameters.
While fine detail is lost anyhow, we do not have to worry about lens
quality, focsing accuracy or a steady hand when taking pictures. And indeed,
under these demands, any leica lens would have troubly to distinguish itself
from  others. Now it escapes me why trying to use this additional 85% of
image potential of a Leica lens, is considered beyond the status of a real
professional photographer.
As the rendition of fine to very fine detail is critically influenced by the
edge
contrast, which is in turn critically influenced by the level of aberration
correction  and the ability to focus critically and have a steady hand, it
is in my view a typical Leica characteristic to exploit this potential (why
have a accurate focussing mechanism and a smooth shutter and a fine
ergonomic shape, if not for supporting the quest for image quality)?
There is a historical dimension here too. The visual impact of many of the
earlier Japanese lenses has been based on the higher contrast of the lower
spatial frequencies, that is the 10 to 20 lines per mm.
read on in part 2.

Erwin