Developing my own E-6....how difficult?
JR
I have done my own black and white, how much more difficult is e-6?
Thanks
JR
Phil Stripling
I haven't done B&W, so I'm sorry to say I can't compare. I used to develop
my own slides till I got tired of the long time involved. It's not a big
investment, and it's not hard. If you do B&W, you can do E-6.
I didn't have a darkroom, so I bought a changing bag, reels, tanks,
chemicals, and such, then did my developing in the kitchen sink using the
microwave as my timer. I think my most expensive item was the official
Kodak mercury thermometer.
Go for it and have fun.
--
Philip Stripling | email to the replyto address is presumed
Legal Assistance on the Web | spam and read later. email to philip@
http://www.PhilipStripling.com/ | civex.com is read daily.
David Littlewood
<jrh...@mac.com> writes
>What kind of investment is needed and how difficult is it to process my own e-6?
>I have done my own black and white, how much more difficult is e-6?
>
Jobo CPE II rotary thermostatic processor about £200
Jobo film dev tank about £25
Decent mercury thermometer about £10
Tetenal 3-bath processing kit (IIRC works out at about £1 per film)
Anything else (measures, funnels, bottles, film clips etc.) you need you
probably have from your B&W work. A drying cabinet is a good idea if you
are going to do a lot (mine is a second-hand Marrut unit with top and
base of metal, and a fabric hanging body; cost under £200).
Prices from memory and may involve looking around for best deal or good
second-hand stuff.
As for difficulty, it involves some care over timing of steps and the
temperature of solutions, but consistency is the most important aspect.
Obviously, try it out on something which is not irreplaceable. The
colour developer does not keep for more than a week or so when
diluted/part used, and if it gets oxidised it will ruin the film (you
get a sort of orange partial solarisation effect), so observe the
maker's recommendations.
You can get away without the CPE II, using inversion agitation, but it
is harder to control the temperature, and inversion processing uses 2-3
times more solution.
--
David Littlewood
Leo
Very true. I do C-41 all the time in my bathroom sink. Very small investment
in equipment. E-6 is very similar to C-41. A few more steps and some extra
chemical. But the equipment needed are the same and low cost.
Leo
Clark Zellmer
inches of water in the bottom and a $10 submersible (sealed) aquarium
heater.
"Leo" <leo...@hotmail.com> wrote in message
news:3B86E9DD...@hotmail.com...
Sandy Ramirez
maintaining temperature control. You can use the same tanks for
processing E6 as you would use for B&W. About the only real investment
is in a good thermometer. I bought a nice one at a scientific surplus
store for about ten bucks.
In article <jrhone-2408...@news.earthlink.net>,
Jriegle
developing tank
four plastic pint bottles
plastic tub for temperature control bath
large spoon to stir the bath
something that measures time in seconds
thermometer ($10 radio shack digital model with external probe will work
fine)
bottle cap opener to remove the top of film can (if needed) and scissors to
cut leader and film off spool
graduated cylinder (actually possible to do without this)
funnel
E6 chemical kit and photo-flo
hanger and spring type clothespins to hang and dry film
counter space near the sink & a dark place to load the film into the tank
You should be able to get all of this for under 60$ You can process up to 5
or perhaps 6 rolls of 24 exp. rolls (you must use chemicals within 5 weeks
after mixing).
I really got to get my E6 processing site online!
John
JR wrote in message ...
Mad
> What kind of investment is needed and how difficult is it to process my own e-6?
> I have done my own black and white, how much more difficult is e-6?
Not very difficult. Check this site. It is all in pictures ....
Don
> What kind of investment is needed and how difficult is it to process my own e-6?
> I have done my own black and white, how much more difficult is e-6?
If you can do B/W and keep a better eye on temp, then you can do E-6. I
used to process (was it...?) E-3 in the bathroom sink when I was a
teenager. It's color, but not rocket science.
Don
monographs, camera manuals, photoshop:
http://www.1world-design.com/book/index.html
A. L. Nelson
http://members.nbci.com/sboukri/develop/indexen.htm
is not available. Any other suggestions?
"Mad" <"MadŠ"@NoSpamo.com> wrote in message
news:3B8916FA...@NoSpamo.com...
Malcolm Stewart
--
M Stewart Milton Keynes, UK
A. L. Nelson <ane...@waterw.com> wrote in message
news:pYJr7.48431$5A3.16...@news1.rdc2.pa.home.com...
Avinash S Chinchalkar
from an old posting... a pretty good tutorial.
http://home.worldnet.att.net/~jriegle/slide.htm
-Avi.
"A. L. Nelson" wrote:
>
> The referenced site
> http://members.nbci.com/sboukri/develop/indexen.htm
> is not available. Any other suggestions?
>
> "Mad" <"Mad©"@NoSpamo.com> wrote in message
T.R. Fineran
isn't critical. The consistancy of chemical temperatures is! In other words,
you can process E-6 at anywhere from 95-105 degrees. What's needed is a way
to keep all chemicals at the same temperature. I've used table top rotary
motors, film tanks and temprature controlled bath for chemicals with
success. I now use a JOBO CPE-2 with better results. Mine is equipped
with the lift. It helps a lot on the filling and emptying of the processor.
Regards
Tom Fineran
In article <pYJr7.48431$5A3.16...@news1.rdc2.pa.home.com>,
ane...@waterw.com says...
>
>The referenced site
> http://members.nbci.com/sboukri/develop/indexen.htm
>is not available. Any other suggestions?
>
>
>"Mad" <"Mad©"@NoSpamo.com> wrote in message
T.R. Fineran
to process your E-6. I have tried several of them and have never been happy
with the results. The results are always muddy looking slides. Use only the
6-7 bath processes. Kodak is very good. JOBO's Tetenol is even better. Both
produce the same results. It's just that mixing and using the JOBO Tetenol is
easier that the Kodak chemicals. Both are about the same price. Also, there's
no difference in proccessing time or temperature requirements.
--
Regards
Tom Fineran
In article <oBqs7.147$yt2....@newsfeed.slurp.net>, TFin...@glblnet.com
says...
>
>Temperature control is the KEY to E-6 processing. The actual temperature
>isn't critical. The consistancy of chemical temperatures is! In other words,
>you can process E-6 at anywhere from 95-105 degrees. What's needed is a way
>to keep all chemicals at the same temperature. I've used table top rotary
>motors, film tanks and temprature controlled bath for chemicals with
>success. I now use a JOBO CPE-2 with better results. Mine is equipped
>with the lift. It helps a lot on the filling and emptying of the processor.
>Regards
>Tom Fineran
>
>In article <pYJr7.48431$5A3.16...@news1.rdc2.pa.home.com>,
>ane...@waterw.com says...
>>
>>The referenced site
>> http://members.nbci.com/sboukri/develop/indexen.htm
>>is not available. Any other suggestions?
>>
>>
Pierre Renault
The original question:
>>> > What kind of investment is needed and how difficult is it to
>>> > process my own e-6?
Of course, the answer to this question is: it depends (on how much experience
you have, what sort of equipment you presently own, how good your lab
techniques are, etc.).
>>> > I have done my own black and white, how much more difficult is
>>> > e-6?
Maintaining a warm temperature (38C or 100F) is a little difficult in most
home darkroom situations. The acidity of the water is a bigger factor than in
B&W, temperature is critical. Assuming that temperature can be maintained, E-6
processing is no more difficult than B&W. Good or excellent E-6 processing,
though, is very difficult to pull off in a home darkroom because its
practically impossible to adjust the chemicals in one-shot processing.
I don't think its worth the trouble, compared to getting E-6 developed in a
good lab, and its usually not worth the cost.
>Temperature control is the KEY to E-6 processing. The actual
>temperature isn't critical. The consistancy of chemical temperatures
>is! In other words, you can process E-6 at anywhere from 95-105
>degrees.
<snip>
The key to processing E-6 is following manufacturer's instructions. ALL OF
THEM.
If you modify the temperature, you introduce changes in the contrast curves of
the various colours which cannot necessarily be compensated for perfectly by
modifying something else (like time, agitation, PH, concentration) in the
process.
>I forgot to mention: don't try to use any of the three or four bath
>processes to process your E-6. I have tried several of them and have
>never been happy with the results. The results are always muddy
>looking slides.
Not surprising considering you think that its not necessary to observe
reccomended processing temperatures...
Pierre
Ted Harris
three bath processes. I use the 5 bath Tetnol most of the time btu have found
no discernable difference between tehir 6 bath and 3 bath process.
Ted Harris
Resource Strategy
Henniker, New Hampshire
Leo
>
> Temperature control is the KEY to E-6 processing. The actual temperature
> isn't critical. The consistancy of chemical temperatures is! In other words,
> you can process E-6 at anywhere from 95-105 degrees.
This is not truth. In fact according to Kodak literature about E-6 chemicals
only the very first processing step needs the temperature control. And it
needs to be at 100+/- 0.5 degree F. All the remaining 5 steps the temperature
is not critical and can be at any room temperature.
> What's needed is a way
> to keep all chemicals at the same temperature.
No true.
> I've used table top rotary
> motors, film tanks and temprature controlled bath for chemicals with
> success. I now use a JOBO CPE-2 with better results. Mine is equipped
> with the lift. It helps a lot on the filling and emptying of the processor.
> Regards
> Tom Fineran
If the temperature for the 1st developer is off your color balance will be off.
Leo
Leo
>
> The original question:
>
> >>> > What kind of investment is needed and how difficult is it to
> >>> > process my own e-6?
>
> Of course, the answer to this question is: it depends (on how much experience
> you have, what sort of equipment you presently own, how good your lab
> techniques are, etc.).
If you have done C-41 at home all you need for E-6 will be identical to what
you already have for C-41, except you will need a few more cups/containers
for chemicals. Only the first developer needs precise temperature control. But
if you are not too critical about the color then it needs not to be very precise.
>
> >>> > I have done my own black and white, how much more difficult is
> >>> > e-6?
>
> Maintaining a warm temperature (38C or 100F) is a little difficult in most
> home darkroom situations. The acidity of the water is a bigger factor than in
> B&W, temperature is critical.
I always use tap water without any problems. I was in that avenue once. I even bought
5 or 6 different PH meters in trying to be precise but then I finally realized that
it was a waste of time. The chemicals simply take care of the correct PH for you
regardless the condition of your tap water.
> Assuming that temperature can be maintained, E-6
> processing is no more difficult than B&W. Good or excellent E-6 processing,
> though, is very difficult to pull off in a home darkroom because its
> practically impossible to adjust the chemicals in one-shot processing.
>
> I don't think its worth the trouble, compared to getting E-6 developed in a
> good lab, and its usually not worth the cost.
This is true. The E-6 chemicals are not cheap. I have long stopped doing E-6
myself. But I am doing a couple of C-41 rolls a week still. If you can do C-41
at home E-6 is just as easy. If you can do B&W I am sure you can do C-41.
It is not much different. Practice with water and a bad exposed film to get
a good feeling of controlling chemical temperature before you do a real one.
>
> >Temperature control is the KEY to E-6 processing.
So is it to C-41. It is no more critical in E-6 than C-41.
The actual
> >temperature isn't critical. The consistancy of chemical temperatures
> >is! In other words, you can process E-6 at anywhere from 95-105
> >degrees.
> <snip>
>
> The key to processing E-6 is following manufacturer's instructions. ALL OF
> THEM.
Kodak never said to do it at temperature between 95-105.
>
> If you modify the temperature, you introduce changes in the contrast curves of
> the various colours which cannot necessarily be compensated for perfectly by
> modifying something else (like time, agitation, PH, concentration) in the
> process.
Temperature change causes density change as well as color balance shift. Don't
try to change the PH value of any chemicals. It won't do any good.
Leo
T.R. Fineran
the KODAK EKTACHROME Film Processing Kit, Process E-6 (1 gallon)". On
pages 3, 4 and 5 it clearly states: First Developer, 6 to 8:30 minutes
depending on 98 to 103 degrees F. It then goes on to tell you that you
can correct for over/under exposure with either temperature or time.
If you're smart at math and logic, you'll figure out that you can
easily process outside the specified 98 to 103 degrees F.
As to cost: the cheapest I've ever gotten by with is: an accurate dial
thermometer, 6 pop bottles for chemicals, a plastic film tank, and hand
rotation of the tank.
--
Regards
Tom Fineran
In article <3BB4CC04...@hotmail.com>, leo...@hotmail.com says...
T.R. Fineran
room temperature at between 90-110 degree F.
--
Regards
Tom Fineran
In article <3BB4CC04...@hotmail.com>, leo...@hotmail.com says...
Pierre Renault
>> >>> > [...]how difficult is it to process my own e-6?
>> The acidity of the water is a bigger factor than in B&W
>I always use tap water without any problems.
I love it when people made broad assumptions based on only their own
limited experience...
Maybe the water is neutral where you live.
Developing large quantities of certain films for example, will modify
the PH of the soup (ask any quality-control tech what happens when you
run a lot of Fuji film through an all-Kodak line). I've worked as a
quality-control tech in a few labs; colour dev PH adjustment is a
normal event in a photolab.
> I even bought 5 or 6 different PH meters in trying to be
>precise but then I finally realized that it was a waste of time.
PH is adjusted by process monitoring (by reading, comparing,
and interpreting control strips, in other words), not by checking the
chemicals themselves. The control strips are much more sensitive to
variations in the process than most measuring devices. Heck, on a
well-run process, its possible to determine the temperature to within
1/20 of a degree Farenheit with a control strip.
> The chemicals simply take care of the correct PH for you
> regardless the condition of your tap water.
Not true, ask Kodak. Some tap water conditions can precipitate some of
the chemical components. Some dissolved metals can also affect the
process. A copper pipe or lead-based solder, for instance, in a
slightly acidic environment will leach dissolved metals into the water
which can then interact with the chemical and the film.
>Temperature change causes density change as well as
>color balance shift.
So do agitation, water concentration, proportions of starters to water
and replenishment, etc.
Decreasing the the temperature of the first developer, for instance,
by one degree F and increasing the 1st dev time to compensate causes a
2-3 CC cross-over of green-magenta line at the speed step and which
shifts over to the yellow-blue line by the time you get to D-Max. Of
course, this is for Kodak film in a Kodak process. Other manufacturers
have other differences (Fuji's chemicals, in other words, don't quite
react the same way as Kodak; the effect of PH on the blue line isn't
the same).
There's tons of published data, available from Kodak, Fuji, Agfa, and
others that confirms all this.
Pierre
T.R. Fineran
KP 78435f 2-91 "Processing KODAK EKTACHROME Films with the KODAK
EKTACHROME Film Processing Kit, Process E-6 (1 gallon)".
KODAK E-6 Rotary Tube Processors
Solution/Step Time min. Temperature
Prewet 4 98 to 103°F
First Developer 6 to 8:30 98 to 103°F
Wash 2 98 to 103°F
Reversal Bath 2 98 to 103°F
Color Developer 4 98 to 103°F
Pre-Bleach 2 75 to 103°F
Bleach 6 92 to 103°F
Fixer 3 92 to 103°F
Wash 3 times 1 ea. 92 to 103°F
Final Rinse 1 Ambient
Dry as needed Up to 145°F
--
Regards
Tom Fineran
In article <LF6t7.1909$CD3.1...@newsfeed.slurp.net>, TFin...@glblnet.com
says...
T.R. Fineran
JOBO TETENAL E-6 Processing in Processors
Solution/Step Time min. Temperature
Preheating tank 5 100°F ± 0.5
First Developer 6 100°F ± 0.5
Wash 2 97°F ± 5.0
Reversal Bath 2 97°F ± 5.0
Color Developer 4 100°F ± 1.0
Conditioner 2 97°F ± 5.0
Bleach 6 97°F ± 5.0
Fixer 3 97°F ± 5.0
Wash 3 times 1 ea. 97°F ± 5.0
Stabilizer 0:30 68°F - 77°F
Dry as needed Up to 140°F
--
Regards
Tom Fineran
In article <bIjt7.1961$Q84....@newsfeed.slurp.net>, TFin...@glblnet.com
says...
Leo
>
> >> >>> > [...]how difficult is it to process my own e-6?
>
> >> The acidity of the water is a bigger factor than in B&W
>
> >I always use tap water without any problems.
>
> I love it when people made broad assumptions based on only their own
> limited experience...
Yeah, my broad assumption was really based on repeatedly measuring PH value
with several different PH meters. Heck, the very first problem I got into
was calibrating them and make sure the probes are preconditioned before
making measurement. You may call that limited experience. I don't think
you will understand why I got so many PH meters just to get limited
experience.
>
> Maybe the water is neutral where you live.
>
> Developing large quantities of certain films for example, will modify
> the PH of the soup (ask any quality-control tech what happens when you
> run a lot of Fuji film through an all-Kodak line). I've worked as a
> quality-control tech in a few labs; colour dev PH adjustment is a
> normal event in a photolab.
I have heard that when a tech is given a ph meter that's when a real crisis
arises. I guess you were never given one, am I right?
>
> > I even bought 5 or 6 different PH meters in trying to be
> >precise but then I finally realized that it was a waste of time.
>
> PH is adjusted by process monitoring (by reading, comparing,
> and interpreting control strips, in other words), not by checking the
> chemicals themselves.
PH is adjusted by adding acid or base. How would monitoring change PH for you?
> The control strips are much more sensitive to
> variations in the process than most measuring devices. Heck, on a
> well-run process, its possible to determine the temperature to within
> 1/20 of a degree Farenheit with a control strip.
You were given control strips, not not PH meters, so that you would not panic
when the meter confused you. BTW, how would 1/20 of a degree matter anything
in terms of print quality control?
>
> > The chemicals simply take care of the correct PH for you
> > regardless the condition of your tap water.
>
> Not true, ask Kodak.
Why not ask yourself? I think many people will agree with me that Kodak lies a
lot. You are right. The condition of tap water matters a lot. I need to take into
account for situations that the water happened to be contaminated by foreign objects
such as waste photo chemical.
Some tap water conditions can precipitate some of
> the chemical components. Some dissolved metals can also affect the
> process. A copper pipe or lead-based solder, for instance, in a
> slightly acidic environment will leach dissolved metals into the water
> which can then interact with the chemical and the film.
You are so right that the tap water is basically not drinkable no doubt.
However, I simply never had a single incident that it ruined my C-41/E-6 work
done by myself at home. Kodak lied in this case by not telling me to use pure
water.
>
> >Temperature change causes density change as well as
> >color balance shift.
>
> So do agitation, water concentration, proportions of starters to water
> and replenishment, etc.
What is water concentration?
>
> Decreasing the the temperature of the first developer, for instance,
> by one degree F and increasing the 1st dev time to compensate causes a
> 2-3 CC cross-over of green-magenta line at the speed step and which
> shifts over to the yellow-blue line by the time you get to D-Max. Of
> course, this is for Kodak film in a Kodak process. Other manufacturers
> have other differences (Fuji's chemicals, in other words, don't quite
> react the same way as Kodak; the effect of PH on the blue line isn't
> the same).
>
> There's tons of published data, available from Kodak, Fuji, Agfa, and
> others that confirms all this.
>
> Pierre
Do you know how to calibrate a PH meter? Information of such is hard to
come by.
Leo
Leo
>
> Just to settle some of these temperature disputes. Right out of
> KP 78435f 2-91 "Processing KODAK EKTACHROME Films with the KODAK
> EKTACHROME Film Processing Kit, Process E-6 (1 gallon)".
>
> KODAK E-6 Rotary Tube Processors
>
> Solution/Step Time min. Temperature
>
> Prewet 4 98 to 103°F
> First Developer 6 to 8:30 98 to 103°F
> Wash 2 98 to 103°F
> Reversal Bath 2 98 to 103°F
> Color Developer 4 98 to 103°F
> Pre-Bleach 2 75 to 103°F
> Bleach 6 92 to 103°F
> Fixer 3 92 to 103°F
> Wash 3 times 1 ea. 92 to 103°F
> Final Rinse 1 Ambient
> Dry as needed Up to 145°F
> --
> Regards
> Tom Fineran
Care to explain why the very last wash (3 times) needs to be at 92 to 103 degree?
What ill effect will result if it is done at 80 degree?
Leo
T.R. Fineran
In article <3BB8CAAF...@hotmail.com>, leo...@hotmail.com says...
norm...@pacbell.net
are absolutely crucial because that is a process that does not go to
completion.
The other process do go to completion, so time and temperature are not so
critical, so long at they are sufficient for the process to indeed
complete.
It is undesirable to subject the the film to extreme differences in
temperature during the process because of the mechanical stresses induced
in the complex relationship between the base and emulsion.
Norm Lehfeldt
tfin...@glblnet.com (T.R. Fineran) wrotf:
Manny Bhuta
the first developer as the tolerance range within which the process will work.
I just read the instruction on the Kodak website and clearly states that the
first developer temperature must be controlled within +/- 0.3ºf. When
calibrating E6 process, temperature is one of the parameter that may have to be
changed so that the resulting control strip is within specifications. However,
if the process is not under control within 98ºF-103ºF range, then changing the
temperature is not going to solve the problem.
--
Manny Bhuta
Randolph, NJ USA
<norm...@pacbell.net> wrote in message
news:3bb8fae0...@news.sf.sbcglobal.net...
T.R. Fineran
The "First Developer 6 to 8:30 98 to 103°F"
means 6 minutes if the temperature is 103°F
and 8:30 minutes if the temperature is 98°F.
You can extrapolate to get other time and temperature combinations.
--
Regards
Tom Fineran
In article <3bb8fae0...@news.sf.sbcglobal.net>, norm...@pacbell.net
says...
edge
first started doing it, maintaining the temperature was pretty
stressful, but once you work out a system for it, processing is
actually more fun (at least for me). here are a couple of things that
i have discovered that make it much easier:
1. you don't have to have a temperature controlled processor (like the
jobo drums) if you don't want to spend the money. i use a $1.50
styrofoam ice chest filled with water and an aquarium heater to
maintain the temperature. it's actually surprisingly effective.
2. you can also try different chemistries. the beseler cs6 kit gives
you a range of temperatures to work with. you can process (i believe
this is right) at 86, 93, 100, or 110. 86 is pretty easy to maintain.
this is the chemistry that i started out using.
anyway... good luck. i hope it works out for you.
john
Pierre Renault
Very very late reply, I was away/busy/off-line...
>> >> The acidity of the water is a bigger factor than in B&W
<...>
>> I love it when people made broad assumptions based on only their
>> own limited experience...
>Yeah, my broad assumption was really based on repeatedly measuring
>PH value with several different PH meters. Heck, the very first
>problem I got into was calibrating them and make sure the probes are
>preconditioned before making measurement. You may call that limited
>experience. I don't think you will understand why I got so many PH
>meters just to get limited experience.
I repaired cameras for a few years for one of the large manufacturers. We used
to get all sorts of people bringing in their $500+ flashes in for repair after
they had tested with their little $300 Minolta/Pentax/Nikon/Whoever do-
everything light-meters. We would put the flash on our $5,000 reflectance
flash test bench and the flash would work perfect every time.
We would then ask to see actual slide or photos demonstrating the problem,
which no one ever had because the flash was working perfectly. I'd usually
end up wasting 5 or 10 minutes explaining to the client that his light meter,
though pretty nifty, just wasn't designed to handle the speeds (faster than
1/20,000 of a sec) that most auto flashes work at, and that despite what his
light meter said, the flash was working perfectly fine.
>I have heard that when a tech is given a ph meter that's when a real
>crisis arises. I guess you were never given one, am I right?
I never needed one, the crises were headed off before they happened, I
guess...
>> PH is adjusted by process monitoring (by reading, comparing,
>> and interpreting control strips, in other words), not by checking
>> the chemicals themselves.
>PH is adjusted by adding acid or base. How would monitoring change
>PH for you?
<sigh> So I worded it wrong...
PH is *tested* by process monitoring, not by using a PH meter.
...and, while we're here, in an E-6 process, one uses either sodium hydroxide
or sulfuric acid.
>> The control strips are much more sensitive to
>> variations in the process than most measuring devices. Heck, on a
>> well-run process, its possible to determine the temperature to
>> within 1/20 of a degree Farenheit with a control strip.
>You were given control strips, not not PH meters, so that you would
>not panic when the meter confused you. BTW, how would 1/20 of a
>degree matter anything in terms of print quality control?
One-twentieth of a degree won't affect the quality of the process. What I was
saying was that *process monitoring* can determine the temperature of a stable
process to within 1/20 of a degree. In other words, I can see a change of
temperature of 1/20 of a degree through process monitoring.
>> > The chemicals simply take care of the correct PH for you
>> > regardless the condition of your tap water.
>> Not true, ask Kodak.
>Why not ask yourself?
<sigh> I've just stated to you that the chemicals don't (can't) correct the PH
regardless of the condition of the water (heck, how does a chemical "know"
what the PH is, and how to correct it, all by itself, anyway?).
> I think many people will agree with me that Kodak lies a lot.
How many people agree with you is not a necessary indication that what you are
saying is true. A lot of people believed the Earth was a flat disk for a long
time, that doesn't make that true either.
First you disagree, then you write:
> You are right. The condition of tap water matters
>a lot.
<...>
Kodak doesn't lie that much. I've worked much more closely with them then you
have, for longer, and in fields you've never touched. Generally, they quite
willing to own up to and fix any goofs they're responsible for.
The large manufacturers (Kodak, Fuji, Agfa) have a commercial/marketing
interest in ensuring that their films are properly processed. They spend huge
sums of money in providing detailed information and in training lab techs.
>You are so right that the tap water is basically not drinkable no
>doubt. However, I simply never had a single incident that it ruined
>my C-41/E-6 work done by myself at home. Kodak lied in this case by
>not telling me to use pure water.
Two points:
While I'm not saying your processing was off, how did you determine that your
colour process were not affected (that's "affected", not "ruined") by PH? Do
you run control strips regularly? Or did you just figure it out by eyeball the
slides?
*Pure* water is not needed for processing film. The water should preferably be
conditioned (i.e. suitable, or made suitable, for processing film). I've even
got a few formulas for developing film in sea water lying around someplace.
>> >Temperature change causes density change as well as
>> >color balance shift.
>> So do agitation, water concentration, proportions of starters to
>> water and replenishment, etc.
>What is water concentration?
The proportion of water to concentrate. In standing tanks (what you find in
just about any machine process), the warm temperature of the chemicals and the
action of the film dryer ends up causing evaporation in the line chemicals.
There's also the chance of a mistake being made during preparation of the
replenisher or working stock solutions.
>Do you know how to calibrate a PH meter? Information of such is hard
>to come by.
No idea, sorry.
I'd assume that to calibrate such a meter, one would have to acquire some
"known" liquids; liquids who's PH has been firmly established with a reference
PH determination method.
Why not contact the manufacturer of the PH meter and ask them? Or perhaps a
chemical supply company? They probably have stable tested PH-calibration
solutions in the catalog for that very purpose.
Pierre
Pierre Renault
>>>> >> The acidity of the water is a bigger factor than in B&W
>
>salts/acids are present (due to buffering capacity). Tap water as
>is, even if slightly acidic, is well suited for E6, due to
>compensating and buffering capacity of the first developer.
I should have made this clearer. The big problem with improper PH levels is
with the colour developer, not with the first.
>>>> PH is adjusted by process monitoring (by reading, comparing,
>>>> and interpreting control strips, in other words), not by
>>>> checking the chemicals themselves.
>wrong, all but one manufacturers publish required pH values and
>specific gravities for all processing solutions. Kodak does it too,
>but for E7, which is E6 mixed on site.
And if you read the process monitoring books all the way through, the one
point that keeps coming back is that process monitoring decisions are always
based on RESULTS, not on what measurements devices (like PH and specific
gravity measurement tools) say or what control methods (control strips and
sensitometry) decide. If a processing line gives absolutely perfect results,
despite what the control strip says, then no change shold be applied (at least
until the reason for a disagreement between the control method method and
results is determined).
I've seen too many processing lines go kaflooey because a geeky quality
control tech decided that his new whiz-bang PH was a better judge of a process
than the customer's film.
>><sigh> So I worded it wrong...
>>PH is *tested* by process monitoring, not by using a PH meter.
>pH is a negative logarithm of H3O+ activity, you cannot measure pH
>by density measurement of a test strip.
Oh yes you can. Check your E-6 process monitoring book.
From the point of view of process monitoring, I don't really care what the
actual PH is, I'm solely interested in whether the PH of a particular chemical
is correct for my type of process.
Pull out your processing error charts (either Kodak's or Fuji's) and take a
look at the charts for PH of the colour dev and compare them to the charts for
agitation. You may notice that colour dev PH is used to compensate for the
effects of greater or lesser agitation (as dictated by the type of process,
hand batches, roller transport, or dip-and-dunk, and by the actual make and
model of the machine).
The whole point of what I was saying previously about the people who kept
insisting that their flashes didn't work properly because their flashmeter
said so, despite their actual photographs being perfectly exposed, was that
what counts, in process monitoring, is the result. If modifications to a
processing line to compensate for variations in agitation (or any other quirk
related to a particular processing line) result in the PH or specific gravity
of one or more solutions deviating from a standard, then that's OK (and ALL
the processing manuals say so).
In other words, if the control strips says the slides are much too blue but
the film comes out perfectly, don't touch anything (at least until you've
figured out why the control strips don't agree with the processed results).
>affected by changes of pH, but it does measure the whole process,
>and there are too many variables, to accredit density variation to
>just one factor. Have you ever heard about measurement uncertainty?
Yes, of course I have.
I may be oversimplifying your statement but keep in mind that PH levels
(specifically, the PH of the colour developer) don't simply affect the
density, they also affect contrast and overall colour rendition (especially
the blue-yellow line).
If my process is otherwise stable (time, temp, replenishment, etc.), and a
change in the control strip matches perfectly known variations in the process
for a change in the PH *and* adding sulfuric acid or sodium hydroxide brings
the process back to standard, then I've effectively measured the PH with a
control strip.
>>>> Heck, on a well-run process, its possible to determine the
>>>> temperature to within 1/20 of a degree Farenheit
>>>> with a control strip.
>what a kind of bollocks!! Just check E6 manual. To detect variation
>of 1/20 of deg, you need to measure the difference of D 0.01 with
>accuracy and precision. Have you got access to such instrument? You
>need to read at least to 0.001.
>0.1 difference in pH has lesser effect than 0.5 °C.
Note I said "on a well-run process". Assuming a stable line and a stable,
repeatable densitometer, I can read a change of 001 despite the inherent
uncertainty of all digital read-out devices (i.e. twice whatever the smallest
measurement is).
If I read the speed line day in and day out and the number is constantly the
same (let's say 077) and suddenly the readings go to 078 *and* the timing of
the change is consistent with a change in the processing environment (let's
say a heater control circuit that is on its way to breaking down or I've
modified the settings of the dryer unit), then I can probably trust the new
reading of 078.
Any scientist worth his salt will tell you that no unverifiable measurement is
worth anything. To verify anything, one must use a different measurement
method than what one is verifying otherwise the risk is that errors inherent
to a measurement method for a given situation will also be repeated during the
verification.
>> [...] I can see a change of temperature of 1/20 of a degree
>>through process monitoring.
>
>crap. you may say that to 1st graders, not to people working in the
>industry for tens of years. it is total fabrication, you were
>mislead at least.. Unless you follow a series of tests, not routine
>test strip run, you cannot determine, which factor is responsible
>for density variation.
Process monitoring is always performed by a series of (ongoing) tests, not by
a single control strip, or even simply by control-strip process monitoring.
And again, I repeat, in the case of variation in the PH, the most noticeable
effect is the *colour cast*, not simply variations in density.
And anyway, temperature variations look like temeprature variations, agitation
effects look like agitation effects, PH effects look like PH effects, etc. ad
nauseam.
>>>> > The chemicals simply take care of the correct PH for you
>>>> > regardless the condition of your tap water.
>>>> Not true, ask Kodak.
>true, if you learn a bit of chemistry, you can calculate the amount
>of say, potassium carbonate required to change pH of a tap water,
>from 5 to 7. In my old school days, we did it in year 7 (still
>primary school).
<sigh> Either I'm not reading the original statement the same way you are or
you are intent on throwing straw men up.
The original statement is "The chemicals [...] take care of the correct PH
for you regardless the condition of your tap water". I read that as "the
chemical will adjust the PH all by themselves" which is what I was disagreeing
with. The method you describe (adding potassium carbonate) involves you doing
something to a solution, not the solution "taking care of the correct PH for
you" all by itself.
I still stand by my original statement.
>><sigh> I've just stated to you that the chemicals don't (can't)
>><correct the PH regardless of the condition of the water
>chemicals DO change pH regardless of the original value, by
>themselves. Read any chemistry textbook.
Perhaps you should read carefully what I wrote. "Chemicals don't CORRECT the
PH". I did not say "chemicals don't modify the PH". Pas la même chose.
>I would say, they limit information, Kodak treats customers like
>idiots. You are expected to follow blindly the instruction without
>asking questions. Unlike Agfa, or Fuji or Konica. Just compare
>published manuals.
<sigh> RTFM, why dontcha?
From publication Z-119 (Revised), Using Process E-6.
"Rather than using a single set of conditions [...],
the approach in this revision is to bring the process into control
by adjusting [first and colour dev]. In this way, Process E-6
can be adapted to various process modes[...]"
The rest of it, as well as *all* of Kodak's (and everyone else's) literature
regarding processing, emphasises that the process usually has to be adapted
for the particular conditions in which it is used.
It sounds like Kodak assumes that people are expected to think a little rather
than, as you put it, follow blindly the instruction[s].
Pierre