[Leica] RE: Horology

[Jim Brick <jim@brick.org>]

To reflect on Erwins thoughts, I have two quick stories.

When digital watches became the rage, I bought one. And then another, and
then another. I finally bought a reasonably expensive Sieko and it worked
(on my wrist) for twelve or so years, and is still working however destined
to a pocket in my LF camera backpack.

After constantly trying to mentally convert a digital clock reading in my
analog mind, I switched back. The last time I was in Switzerland, I bought
an Omega Speedmaster and was able to pick it up at the Omega factory in
Biel. Wonderful experience. And an absolutely wonderful watch. A joy to
have and use. Fully mechanical. Very analog. Just like film. And it exudes
craftsmanship.

Besides being a photographer, professional from the standpoint that I went
to Brooks Institute of Photography, worked as a commercial photographer for
many years, currently teach workshops and take/make/and sell fine art
prints from 20x24 to 48x60, I am an engineer. I am in the middle of
designing and producing a digital camera for RCA. We have used all of the
latest digital sensors from 1/4" to 24mm square, from .5 megapixels to 6
megapixels.

Digital sensors cannot compete with film. I've given a dissertation on this
before so I won't repeat it now. But simply, and roughly, it takes four
pixels to record one true color pixel. Pixels cannot be made smaller than 3
microns square. Four pixels = 36 square microns. So in 36 square microns
you get a single RGB 24 or 36 bit pixel.

The average size of a silver halide grain is one square micron. Some
larger, some smaller, but the average in normal film like APX 25 or
Kodachrome would be around one micron square. Within this one micron, there
are, on an average, 20 BILLION silver halide molecules that can be struck
by a photon and converted to silver. It takes several molecules
participating to record a "speck" of silver. So even if we divide by
twenty, we have a density range, within one square micron, of a billion.
Rather than 4096 levels of density (twelve bits per physical pixel) in nine
microns square or sixteen million combined color densities in 36 square
microns.

The net result is that you cannot record fine detail using a digital sensor
unless you are willing to make multiple scanning passes, with a micron or
two shift of the sensor on each scan, and then use a very sophisticated
computer program to process the multiple images and ferret out what the
fine detail was. This is one of the techniques astronomers use to capture
fine detail in astrophotography. But alas. You need a static subject,
sophisticated camera sensor mechanics, and a very sophisticated processing
system.

Hardly an M6 with a 35 ASPH lens and Kodachrome or APX 25. Which will still
win the fine detail war, hands down. And you can carry it in your pocket.

Jim


At 10:32 AM 7/22/00 -0400, Austin Franklin wrote:
>> If I take a picture of a car with small
>> reflections in the headlamp, I know there are details within the
>> reflections, that good silver images can extract (and digital prints
>> cannot).
>
>I am curious if you have actually done this?  If you have a particular 
>negative that you believe shows 'this', and you believe it can not be shown 
>with current digital prints, I would ask you to send me the negative (and a 
>print) so I may scan and print it and send the digital print back to you 
>for evaluation.
>
>> But the purpose of the
>> swiss watch is not the mere indication of time, it is the embodiment of a
>> century long drive to measure time to the smallest fraction.
>
>Far more than a century!  ...but actually, precision was born out of 
>necessity.  Watches prior to the late 1800s were not very accurate, since 
>there was no need for higher accuracy at the time (so they thought!).  And 
>as such, trains were crashing into each other!  Then standards were 
>established for a 'railroad' watch in order to avoid train crashes.  Also, 
>railroad watches had to have two mechanisms for changing the time on the 
>watch, so the time could not be inadvertently changed...
>