[Leica] Digital and Leica, etc.....

["tlianza" <tlianza@sequelimaging.com>]

Hi to all,

I have been reading the various comments on the topic of digital and leica
imaging that have been going around on this list.  My background is imaging.
I designed my first solid state scanner in 1978.  I have a Masters degree in
Photographic Science, I have designed lenses and digital imaging systems my
entire adult life.  The following are my observations.  I own Leica M and R
cameras as well as Nikons.  I own the new Nikon Digital D100 and I have run
a series of tests using the Nikon against the Leicas and Nikon analog
cameras.  I scanned a number of samples balanced the color etc in photoshop
and then had them printed on Fuji frontier printer at 10X15".  I then showed
the images to 10 observers and had them choose the "best" image.  In all but
one case, they selected the digital camera images.  The one case where there
was some uncertainty was an image captured on an R6 with the 80mm Summilux.

The one thing that became striking evident was that test was strikingly
unfair from one point of view, and totally fair from another. The inclusion
of the scanner/sensor MTF basically negated the resolution and MTF quality
of the Leica combinations. The output of the test was limited by the
scanning and printing process.  I ran some numerical simulations and found
that a diffraction limited scanner, would still not beat the Digital in
terms of subjective quality, without substantial image processing.  The
problem with the image processing step was that it would enhance grain noise
and that just would not work at big enlargements.  The noise levels in the
Nikon D100 were always lower than those in the Leica.  If you are working in
a pure digital workflow, the digital camera normally wins from the
standpoint of subjective quality.  I don't think that you can get the same
quality as the >6 mega pixel cameras regardless of the scanner.  If you are
sourcing images that are going to be electronically reproduced, the
comparison is fair: it's going to take more time and work to get a good
image using the analog camera. You are probably better off just using the
digital in this case.

If you are agonizing over absolute objective quality, a much fairer test is
comparing the analog image produced using an enlarger and conventional
techniques to the printed image from the digital system  Now, in this case,
differences due to resolution can be seen.  The resolution of the analog
image is greater without question, but the subjective testing still leans
towards the digital system due to the apparent sharpness. If an individual
takes out a loupe, the analog image wins hands down. Look at normal viewing
distances, the issue becomes far less obvious.  One of the big difference
between leica lens design and other camera manufacturers is leicas obsession
with the LOW FREQUENCY mtf.   The leica lenses resolve really well, but they
are outstanding in terms of contrast in the lower frequencies. When enlarged
to 8X10 the area of mtf that the leica designer seems to stress falls in the
"sweet spot" of the visual mtf which peaks at a fairly low angular
frequency.  Proper digital processing can simulate this, so without the
loupe, it's tough to see.

The work that I have done convinced me that I could reliably produce
subjectively good images up to 10X15 using a digital camera. More important,
the image quality of the digital camera was overwhelmingly selected by other
observers.  My gut tells me that I will have to work real hard to get a
better image in the darkroom, but I might be able to do it.  I'll just have
to run the test when I get the time. There is no question that these digital
cameras are capable of great results.  I have not met a single photographer
that has NOT embraced digital for SOME aspects of their work after doing a
side by side comparison. Will digital replace film? In some areas it has, in
some areas it never will.... I Always carry an analog camera body in the
digital kit. I'm reminded of the photographer who was trapped in the Church
in Bethlehem...her battery ran out the first day.   Certainly, if you're in
the field, you are taking a big risk.  At extremes of temperature and
humidity you are taking a big risk relying on digital.  If you work in
Primarily in Black and White, digital is a waste of time, in my opinion. On
the other hand, once you've printed a color image on a Fine Art paper, it's
very hard to go back to RA-4 or Ciba prints.




Tom Lianza
Technical Director
Sequel Imaging Inc.
25 Nashua Rd.
Londonderry, NH 03053
tlianza@sequelimaging.com


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