hyder@hpfcpkh.UUCP (06/08/84)
The difference between Kodachrome and Ektachrome is one of how
the color dyes are included. In Ektachrome they are in the
film at manufacture and the processing causes them to become
colored. (The coloration reaction is reversable, back to a
colorless coupler, so they fade in the presence of oxygen.)
Kodachrome is a three layer film with coupling sites coated into
the emulsion but no color couplers. The couplers are in the
chemistry. (Yes, that means three color developers instead of one.
They are sort of pretty when you look at them.) The dyes are not
the product of the processing reaction and are quite a bit more
stable.
Why not do Kodachrome at home? The chemistry is complex, not
mass produced, and hard to control. An analytical chemist on the
staff is critical to these processes. The base components are
available only in large quantities and the machines to process it
were $0.5Million last time I checked.
Kodachrome is processed by Kodak, Fox Stanley, Fotomat, Berkey,
Nashua, ... (i.e. the larger labs that need the job done and have
the money to invest for a long term return.) With color coupler
recovery, the cost to process a roll of Kodachrome is less than
$.25(twenty five cents). All you need is the set up costs
and lots of film to process, the lines are hardest to control if
they're not used enough.
One other note, Kodachrome has a color balance that is a little
more toward the red side. Great for mountains, not too good for
beaches or deserts. (Unless you like things warm looking.)
Me, I shoot Kodachrome and send it to Kodak. The control is
the best, and you get to pay for that fact. Most of the labs
do a reasonable job, try them if Kodak prices are too much for
you.
Paul Hyder { ...!hplabs!hpfcla!hyder }hartley@uvm-cs.UUCP (Stephen J. Hartley) (06/19/84)
Could somebody explain the differences between Kodachrome and Ektachrome slide film? Why is it that only Kodak can develop Kodachrome? Does that mean it is better? Thanks. "If that's true, then I'm the Pope!" Stephen J. Hartley USENET: decvax!dartvax!uvm-gen!uvm-cs!hartley The University of Vermont CSNET: hartley@vermont ARPANET: hartley.vermont@csnet-relay
mauney@ncsu.UUCP (Jon Mauney) (06/20/84)
It's not that nobody but Kodak CAN develop Kodachrome, it's just that hardly anybody else does. Almost all color positive materials use the same basic process (Cibachrome is an exception). First the image is developed into a black and white negative (in three layers, corresponding to the three colors). Then the image is reversed, yielding a positive, the color dyes are formed, the negative is bleached out, the image is fixed, and voila! a picture results. In the Ektachrome process, there are only a handful of steps, simple enough for home darkrooms and shopping center photo processors. But Kodachrome (an older process) develops and reverses each layer separately, resulting in a very large and complicated processing line that not everybody is willing to mess with. Hence the relative (but not total) lack of independent Kodachrome processing labs. As for which is better, that's a matter of taste; the two films are indisputably different. Kodachrome slides will last much longer than Ektachrome, and Kodachrome is regarded by many as the finest color material available. On the other hand, if you want 200 ASA film or next-day processing in many cities, Ektachrome has a certain appeal. And then there's Fuji ... -- _Doctor_ Jon Mauney, mcnc!ncsu!mauney \__Mu__/ North Carolina State University
dsg@mhuxi.UUCP (GREEN) (06/21/84)
[] As a result of an anti-trust suit brought against Kodak, by the Justice Dept. in the mid 1950's, Kodak agreed to let indpendent photofinishers develop Kodachrome. Kodak also introduced Ektachrome for exclusive photo- finishing by the independents ( Fox-Stanley, Colorcraft, Berkey, et. al.). Currently, less than 5% of all color photofinishing is chrome, be it Koda or Ekta. This means that most photofinishers either send chrome to a "specialist" or to one of their larger labs or to Kodak. As to the difference in "quality", if *you* can't tell the difference or are happy with what you're currently using, stick with it! David S. Green mhuxi!dsg 201-564-4468
kiessig@idi.UUCP (Rick Kiessig) (06/22/84)
Speaking of Kodachrome vs. Ektachrome, there's an experiment
I've often wanted to do. Shoot the same scene in the same light
with two different cameras: a 35mm and a 6x7 (Pentax or equiv),
and in both Ektachrome and Kodachrome. Then blow the negs up to
at least 8x10 (11x14 if budget allows) and take a look at the
difference in quality.
Now we all know that there's going to be a significant
color difference, and that Kodachrome is supposed to be sharper
than Ektachrome. But will a 6x7 Ekt neg produce a clearer picture
than a 35mm Kodachrome neg when reasonably enlarged?
--
Rick Kiessig
{decvax, ucbvax}!sun!idi!kiessig
{akgua, allegra, amd70, burl, cbosgd, dual, harpo, ihnp4}!idi!kiessig
Phone: 408-996-2399mat@hou5d.UUCP (M Terribile) (06/23/84)
Regarding the ``next day processing available in many cities'' for Ektachrome
(must be a TM of Kodak), when I worked in NYC, I used a small lab that did
*four-hour Ektachrome*. Price? 10% below Kodak list for the same work. In
other words, not cheap, but not custom priced either.
If anyone cares to know where the place is, send mail and I'll reply.
--
from Mole End Mark Terribile
(scrape .. dig ) hou5d!mat
,.. .,, ,,, ..,***_*. (soon hou4b!mat)