Archived posting to the Leica Users Group, 2000/04/24

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Subject: [Leica] K-chrome cont'd
From: Erwin Puts <imxputs@knoware.nl>
Date: Mon, 24 Apr 2000 10:59:41 +0100

There is no difference in grain size between amateur and prof 
versions of K-chrome. Kodak states in their documentation that the 
differences in RMS values are due to changes in the measurement 
method.
K64 can be best exposed as EI-80, making the speed difference with 
P100F marginal.
I did compare the Kodak 100EC and VS with the others, and found the 
same characteristics to hold: Kodak is slightly grainier, but with a 
higher edge sharpness, giving the rendition of fine detail a slight 
boost.
Again I have to emphasize that all these films from K25/64 over V50 
and P100F to E100EC/VS are a match for Leica lenses and most 
importantly a challenge to anybody's technique. Scanning these films 
and printing them with one of the ubiquitous Epson printers degrades 
the inherent quality to a degree that the quality converges to a 
common level.
Note that I explicitly exclude color saturation as a comparison dimension.
This class of films defines current emulsion technology and image 
quality: I shoot most of my Leica lens test series (NO NO , not the 
topic again  of  me taking pictures of newspaper pages as my test 
object? I do not!)  with all of these films with two goals: to see 
under what circumstances the Leica lenses deliver different (may I 
dare say: better?) quality and to see what is the influence (if any) 
of the different characteristics of the emulsions on the optical 
quality as designed and implemented by the Solms engineers.  In my 
view the equation is:  optical quality + emulsion quality = image 
quality.
It is in my view very difficult to discuss IQ without taking into 
consideration the EQ.
The relations between and the effects upon the different parts of the 
equation (not to mention the minefield of trying to agree on a 
definition of OQ, EQ and IQ) are very complex and defy any simplistic 
statements.
These issues have to be discussed in a relaxed attitude with the 
common goal of finding the truth and if the holy grail seems to elude 
us, the appropriate way is to find ways to further the understanding 
of these exciting topics.
I must say that I am now doing serious testing since 8 years and 
having used all and every B&W, color neg and slide film on the 
market, I am still unable to make any definite and conclusive 
statements.Well a few actually, but again one has to be sensitive to 
all kinds of external influences and situational characteristics.
  I have testseries where the K200 beats the E100 and I have series 
where I wonder if it was taken with V50. Sometimes even the Astia 
film delivers outstanding results. What I am looking for however is 
consistency and reproducibility under various conditions. And a kind 
of bottom line standard.


Erwin