From: rspeirs@javelin.sim.es.com (Ron Speirs)
Subject: Re: Color balance setups for specific films
Organization: Evans & Sutherland Corp.
Date: Wed, 16 Dec 1992 18:59:05 GMT

In article <1992Dec11.122720.5941@sys.sweden.dg.com> robert@sys.sweden.dg.com (Robert Claeson) writes:
>In article <1992Dec3.023046.21629@walter.bellcore.com>, hsong@ardour.bellcore.com (G. Hugh Song) writes:
>
>> Don't those commercial lab have their own standard sets of color balance 
>> setups for well-known negative films?
>
>None are typically needed for different films.
>
>> What kind of printing machines do those heavy-volume labs use for roll-film
>> processing and printing?   
>
>More sophisticated and automated. Each neg is individually analysed by a
>built-in color analyser and the filtration is adjusted accordingly. This
>is why no individual settings for each film is needed.

In my opinion, this is one of the reasons that so many of people's lab-
produced prints look so BAD.  The built-in analyzer makes an assumption that
the frame should average to gray.  It then dumps in a LOT of correction when
it sees a predominant color in the frame.  Unless a human intervenes, the
enlarger/analyzer/printer makes cyanotic skin tones of the person wearing
red, magenta tones on the person lying on the grass, dark gray snow of the
properly-exposed snow scene, etc.,etc.

> The analyser just
>tries to get the average of the colors correspond to some calibration.
>It does this by changing the filtration. The paper is on rolls, usually
>150 or 300 meters long. I can't tell if this is true for the Fuji lab
>that you use, but several professional labs around here uses this method.
>
>I'm afraid that the "best" method is to order processing of the negatives
>and a color contact sheet and then order larger prints from exactly the
>frames that you want.
>
Let me report on a recent test conducted by the Photography Club here where
I work.  Eight identical rolls (same date code) of Kodacolor Gold 100 were
exposed to a variety of subjects using the same lens and manual exposure
control.  Most of the shots were taken in midday sunlight.  These eight
rolls were then taken to eight different photofinishers around town,
representing one-hour labs, supermarket labs, Qualex, a local wholesale
lab, a professional lab.  No comment was made regarding the test and
standard, 3.5 x 5 prints were ordered.  The scenes were:
   1.  Gray step card, underexposed 1 stop   (Kodak Q-16 card)
   2.  Gray step card, normal exposure
   3.  Gray step card, overexposed 1 stop
   4.  Gray object in front of red background
   5.  Gray object in front of green background
   6.  Gray object in front of yellow background
   7.  Gray object in front of gray background
   8.  Poinsettia plant (artificial) against green grass
   9.  An almost-white stuffed animal against green grass
  10.  An orange-colored squash against green grass
  11.  A red rose among green leaves
  12.  A yard scene containing light objects and deep shadows
  13.  An indoor flash picture of a stuffed animal

The results were mixed, but certain general conclusions could be made:
   A.  Few labs were able to print the standard gray card properly;
       results ranged from brown to green to blue.
   B.  The quality from the professional lab was worse than the other
       less-expensive labs.  You can pay more, but that doesn't guarantee
       better quality.
   C.  The skin tones of the person holding the gray object in 4 thru 7
       were highly influenced by the background color, and in many were
       washed-out.
   D.  The light subject in 9 caused extremely dark grass.
   E.  The papers used by most processors could not handle the brightness
       range of sunlit and shadow portions of 12.
   F.  Even though the gray card frames were bracketed, they all appeared
       identical in the prints.

But by far the most SHOCKING result of the test was a contact proof sheet
of the first 5 frames of each of the 8 rolls.   I had always thought that
C-41 was C-41, and that most labs kept their C-41 processing lines in
tight control.  NOT SO!  The proof sheet showed 1.5 - 2 stop density
difference between the lightest and darkest roll, and at least a 20-unit
color difference among some of them (as referenced to my experience with
a Beseler color head).  The only variable in this test was which lab
processed the film.

To show that a properly balanced print of the gray card could be obtained,
I printed the normally exposed (frame 2) negative from each roll.  These
prints were all uniform, but each required significantly different filtration.

Now I realize that this test is just one sample in time of these labs, and
some may have been having a "bad day".  But that is the chance you take.
IMHO, I think that a lab having a "standard filtration" or "channel" for
any kind of film and getting successful prints by just using that is a myth.
There are so many variables in age of film, batch, storage conditions,
film processing - including the analyzer running amok - that there is NO
substitution for an intelligent, live person to look at the prints and
judge whether or not they are reasonable.  If your lab has such a person,
great.  If it doesn't, then YOU are that person.  Expect reasonable quality.
If your lab doesn't deliver it, change to a different lab.

Ron Speirs, Evans & Sutherland Computer Corp., Salt Lake City, Utah