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-   -   C41 problems (http://www.film-and-darkroom-user.org.uk/forum/showthread.php?t=13282)

alexmuir 28th June 2020 12:43 PM

C41 problems
 
I’ve just developed my first two colour films using the Bellini kit. It consists of developer, bleach, fixer and stabiliser.
I made up the chemicals as directed, and heated them, except the stabiliser, to 38C. I used the times of 3min 15secs, 45 secs and 3.00min for the first three chemicals. Stabiliser was a short dip at room temperature (22C).
I hung the strips up to dry at room temp.
I have a row of white dots, like water marks, only more solid white, down the full length of each film. This came off when rubbed with alcohol, but I want to avoid it in future. It is obviously something to do with the stabiliser bath. Should I squeegee the film, or wipe it with a sponge?
The second issue is that I detect a slight bluish cast when the negatives are viewed as positives (I’m being careful here!) on a screen. I only need to know if that could be either;
Process temperature not exact
or
Film has aged badly
The films were not ancient, but could have been close to their stated expiry dates.
Any advice is most welcome.
Alex



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Mike O'Pray 28th June 2020 01:37 PM

A difficult one Alex. It might help if you were able to show us photos of the negs. Do all the negs exhibit this bluish cast and was this apparent in negative form.
The white spots might be a stabiliser issue and this may seem perverse to say this but if the spots can be wiped off then this may be much the lesser of the two problems.

A cast may or may not be colour crossover which cannot be corrected under an enlarger but it may be that your scanner is doing something that you are unaware of and it is this that is the problem

Ideally try and print on RA4 paper and see if the cast remains or if filter correction eliminates it does that same filter correction introduce other colour problems? If it does the latter than colour crossover is suggested to me

However first things first. Can you take a digital pic of the negs? Against white paper on a window might be OK. A digital pic of a neg is a more accurate representation of the "true " neg than a scan that has been reversed.

Mike

DaveInElland 28th June 2020 03:01 PM

I don’t have the experience to answer your question Alex but for what it’s worth I’ve developed around 20 rolls using the Bellini kits without either of the problems you are describing.
Regards

alexmuir 28th June 2020 04:12 PM

Thanks Mike and Dave. I’ll try to put up a picture of the negatives. I don’t intend printing by chemical means at the moment, and I want to avoid talk about scanning, although I know that may be an issue. I just wondered if variation in temperature, or poor storage were likely to cause a cast.
The other issue is something to do with stabiliser, but I’m not sure how best to deal with it. It may be that wiping the film when wet is the cure. https://uploads.tapatalk-cdn.com/202...435f70d45b.jpg

Alex


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alexmuir 28th June 2020 04:45 PM

Since posting, I realised that I have some negatives freshly processed by Ag PhotoLab. I ran them through the same electronic device, and I can see that it is the problem.
I’d still be keen to hear from anyone who has experienced the water mark problem. Is it sensible to squeegee, or is there another option?
Alex


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DaveInElland 28th June 2020 06:10 PM

FWIW, I don’t squeegee my C41 negs Alex but what I do do is soak my fingers in the stabiliser and gently run the film between two fingers to remove most of the excess. I also leave the film in the stabiliser whilst I clear up everything else and before giving them a dunk in some fresh stabiliser immediately before hanging. My only experience however has been with the Bellini kit and I only started processing colour this year so I’m by no means an expert!
Regards

Mike O'Pray 28th June 2020 06:12 PM

Alex I think you are saying that the scanner is the problem. If this is the case then this is good to know in one way as it means it isn't a processing issue in either the method or chemicals.

I am amazed at the number of "hybriders"on Photrio who have apparent film problems and who then discover when told to check their scanning software or adjustments that it is the scanner

In general terms a digital picture of a negative be it B&W or colour is the best way for others to begin to analyse negative problems. I am no expert in reading C41 colour negs but your pics of the negs suggested to me that the negs were OK before I got to your last post

As regards wiping, I'd try a minute in the stabiliser while swishing the film around quite vigorously and then using the two middle fingers to wipe the film. If the spots are sticky enough to resist wiping with fingers then a squeegee might be the only way. Just make sure the blades are wet and flexible and that there is nothing on the blades to "score" the film.

I used a squeegee for years without issue but now I find that two middle fingers are as good and safer as there is no grit on my inner fingers anyway and it avoids an examination of the squeegee each time. Frankly if the blades haven't hardened with age and are clean then I fail to see how a squeegee can cause scratches.

Mike

alexmuir 28th June 2020 06:48 PM

Thanks Mike. I will squeegee, or wipe the film as you suggest. I think removing the marks afterwards with alcohol is more likely to cause scratches than wiping when still wet.
Alex


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Mike O'Pray 28th June 2020 08:00 PM

Alex this may be redundant advice but it is worth looking at the fixer to see if there is any white precipitate in it and also the stabiliser. In a sense I hope there is as that establishes what chemical it originates from. Filtration through a coffee filter might be worth while and then maybe notifying whoever sold you the Bellini kit.

I always think that telling the seller is to the seller's advantage anyway and may get you a replacement chemical. If it were me and I had a batch of chemical that I was selling that was defective I'd certainly want to know.

Mike

John King 28th June 2020 09:14 PM

White spots
 
I am not sure that it is the Stabilser bath.

In over 30 years of developing C41 I have never ever had a problem with the stabiliser in any shape or form.

I use either Fuji pro kit or the Tetenal kit and both have the same times right through 3min 15s for the developer. 6 mins for both the fixer and stop bath all at 38c and 1 min for the stabiliser. I don't recognise the two intermediate times you mention 45seconds and 3 mins. Are these the times for the bleach and fix? I have never used a Bellini kit, but as they are generic I cannot see them being different with the times of the other kits, especially as the development times are the same. 45 seconds and 3 mins are way too short unless Bellini say different.

The stabiliser should be (and this is universal with C41 and E6) 1 minute at 38C static (No agitation) I would caution most strongly against using a squeegee to wipe the film. Colour film is very soft after development and it will SCRATCH with little pressure. Not it MAY scratch but WILL I have seen a new unused 'J' cloth dampened and folded several times and one wipe the full length of the film. That seems to work OK, but I still don't trust it though.

You seem to have decided the colour imbalance is due to your scanner which is not unusual. Although with home processing there will occasionally be slight differences which can be corrected in the printing stage.

It is not unknown that the bleach concentrate will form a little sediment so the way I would deal with that is to filter the working solution before use. A simple plastic funnel and a coffee filter paper will be enough.

It also depends on where you live as well. If your water is 'hard' then that can give the problem you describe with chalk suspended in the water will form a precipitate. Luckily I live in a 'soft' water area.

I also doubt if the age of the film is a problem The expiry dates for C41 are conservative to say the least, so long as the film has not been left near a heat source for a while, then that will have no bearing on the quality.


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