Problem : cyan cast on C41 negatives

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Anirban - 08 May 2007 17:33 GMT

Hi everybody !
I am a newbie trying to develop C41 films on my own. I have a fairly
dark darkroom and photo chemicals from Kodak. This kit is sold only in
South Asia. In short, the dilution instructions specify that it can be
used to make 4 litres of developer, and 2 litres each of the bleach,
fixer and stabilizer . I also followed the instructions about the
temperature (about 100 degrees Fahrenheit) as well as the process
times (6 steps : additional two washes).

The problem is that the developed negative comes out with a cyan cast
every time (4 times so far) and the resulting photograph has a reddish
tinge which masks out all other colours very effectively.

Does anybody know what might be happening here ?

--- Anirban Brahmachari.

P.S. I use a red lamp in the darkroom and keep it switched on for a
minimum duration. Could it be the cause of this problem ? If so, the
tinge should not be uniform but as a matter of fact, the tinge IS
UNIFORM. The lamp stays on at a very low power (light output
equivalent to a 5W incandescent lamp at 10 feet) for about a minute
during the first two stages (development and bleaching).

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gr - 09 May 2007 04:48 GMT

> Hi everybody !
> I am a newbie trying to develop C41 films on my own. I have a fairly
[quoted text clipped - 19 lines]
> equivalent to a 5W incandescent lamp at 10 feet) for about a minute
> during the first two stages (development and bleaching).

Something does not sound right; c-41 is a color process, so a red
safelight would not work and will fog the film. Try with no safelight.
Also, the darkroom has to be really, really light-tight; sit in it dark
for at least 5 minutes in the dark and see if you see anything; luminous
clocks, dots,, leds on radios or timers; all of these can do nasty things!

gr

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Stephen - 09 May 2007 14:50 GMT

>Hi everybody !
>I am a newbie trying to develop C41 films on my own. I have a fairly
[quoted text clipped - 19 lines]
>equivalent to a 5W incandescent lamp at 10 feet) for about a minute
>during the first two stages (development and bleaching).

You can't use a safelight or have any other light source in the
darkroom while developing color film.

The cyan cast can also mean that the bleach has contaminated the
developer.

Stephen
--

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Rod Smith - 10 May 2007 17:12 GMT

> I am a newbie trying to develop C41 films on my own. I have a fairly
> dark darkroom and photo chemicals from Kodak.

First, "fairly dark" doesn't cut it. One way to test is to seal yourself
in your darkroom for about ten minutes with the light out. (Use a timer
with a beeper.) At the end of that period, if you can make out a sheet of
white paper held at arm's length, the darkroom isn't dark enough; locate
and patch the light leaks. That said, given your symptoms, I doubt if
darkroom light leaks are the source of your problem, unless you've got
some colored glass or something that's letting in red light but not other
colors.

> I also followed the instructions about the
> temperature (about 100 degrees Fahrenheit) as well as the process
> times (6 steps : additional two washes).

C-41 is much more temperature-sensitive than B&W, so you shouldn't be
sloppy about that 100 degrees F target. If you're using a manual
developing tank, use a water bath to hit as close to 100F as possible. I
doubt if being a degree or two off would cause the sort of severe problem
you describe, but you should definitely eliminate this variable.

> The problem is that the developed negative comes out with a cyan cast
> every time (4 times so far) and the resulting photograph has a reddish
> tinge which masks out all other colours very effectively.

...

> P.S. I use a red lamp in the darkroom and keep it switched on for a
> minimum duration. Could it be the cause of this problem ?

If the film itself is exposed to red light, then that's almost certainly
the cause of the problem. A red safelight is *NOT* safe with ANY color
material, AFAIK. For that matter, a red safelight isn't safe with most B&W
films, either; it's useful mainly for B&W papers.

> If so, the tinge should not be uniform but as a matter of fact, the
> tinge IS UNIFORM. The lamp stays on at a very low power (light output
> equivalent to a 5W incandescent lamp at 10 feet) for about a minute

Consider this: A one-minute in-camera exposure of most films will be
enough to produce an image (and perhaps completely blacken a frame) in any
but the very dimmest of light. When the film is exposed directly, rather
than through a lens, the film will get even more light, Thus, the exposure
you describe could well be completely fogging the red-sensitive layer of
the film, hiding any non-uniformity by the extent of the fogging.

> during the first two stages (development and bleaching).

This last phrase throws a monkey wrench into my whole analysis. If you're
saying that you're using the red safelight only AFTER the film is loaded
into the tank, then it shouldn't cause problems. AFAIK, all mainstream
development tanks are "daylight" tanks -- they're designed to be used in
normal lighting conditions, and require darkness only when you're loading
the film into the tank. If your tank is leaking light, I'd expect streaks
or fogging along an edge or the outer spirals of the film. OTOH, if you're
using the tank with its lid off, if your safelight is on when you load the
film into the tank, or if you're using some very old or unusual equipment
that is NOT light-tight, then your safelight is still very probably the
cause of the problem.

Signature

Rod Smith, rodsmith@rodsbooks.com
http://www.rodsbooks.com
Author of books on Linux, FreeBSD, and networking

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Anirban - 11 May 2007 17:41 GMT

PROBLEM FIXED.

Thanks everyone. The problem was indeed the red light.
This time I did it without the red light and it worked fine.

Thank you so much.

I really don't appreciate why people flock to social networking sites
these days when there are so many helpful people on Usenet.

--- Anirban Brahmachari.

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UC - 22 May 2007 20:56 GMT

You are a moron. Why do people like you exist?

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