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Discussion in 'Color: Film, Paper, and Chemistry' started by Color Photographer, Sep 10, 2011.
Does anybody know what can cause an magenta cast in C41 development?
Magenta cast in the print? The negative? The mask?
What process are you using?
What temps & times?
How are you washing?
I scan the negatives.
The images have the cast. I use different processes Fuji Hunt and tried some home brew too and develop in an small tank.
80% of my Images have more or less an magenta cast.
I tried different temperatures, different agitation. I solved all other problems
but all my images still are reddish/magenta.
How can I get image that tends toward yellow?
Is the magenta cast because a low density in the cyan dye laver?
An overdevelopment of the first dye layer?
Maybe the ph is to high?
How did you verify that it's the film and not your scanning technique?
Some negatives developed at different photo labs scans ok.
I only have an BW Enlarger and cannot try prints myself. So I only scan.
My explanation is that the first two dye layers on the negative are overdeveloped,
and the third, the cyan dye layer has an low density and is underdeveloped but I dont know if I am right.
I tried to rise the ph up to 11,5. It seems to be the wrong way.
Maybe I dont understand and my thoughts are completely wrong?
Two thoughts here.
First, given you have one lab that works and one doesn't, talk to your labs, it may simply be that one cares and one doesn't. They should also be able to tell you if your negatives are over exposed or under exposed.
Second, with regard to scanning questions and all that digital color balancing jazz, APUG isn't really the best source, in fact it's off topic. http://www.photoshopuser.com may be a better place to ask. Lynda.com has tutorials on scanning too.
Thanks, but the negatives from all labs I tried yet are ok on scanning.
The negatives that I developed myself have the problem!
So I dont think its the scanning. It seems to be my development.
So back to my original questions.
If the scan is too magenta, the film is too green. This can come from a variety of effects including fog, improper development and a host of other things. Since I have no idea what your workflow is, I cannot judge but if it is truly magenta then the problem is in the yellow and cyan layers or in the magenta layer.
Is the entire film greenish? Or, is just the image area greenish? Or, is there no cast to the negative in any way, but it scans magenta? This might help evaluate the problem.
Your comments and your knowledge are so valuable!
As you remember I just try some experiments on developing.
1. Yes the negatives are greenish in the image area and the perforation area at the edge is greenish too. On negatives that brings better result the perforation area looks more orange.
2. I try to keep an development at 25 C with one agitation every 30sec at 21min.
3. Can the PH be the problem, it is at 11,5 should I lower it?
4. I tried Fuji Hunt Chemistry and some own variations. The only effects seems to be on the saturation, sharpness and developing time, but all have more ore less the magenta cast on the scans. (I cut an film into small pieces to be able to compare the results)
5. Adding some Sodium Carbonate to the developer seems to help a little. Can this be?
6. Maybe the Starter (Bromide) is to much or too low?
7. It would be great if I not only can get normal negatives but the opposite slight yellowish images.
is this possible?
(All my films are from the same batch that brings normal results developed at pro labs. Also I tried some other brands, the same)
Look at the C41 formula published here on APUG. It is nearly correct. Your pH is far too high. The correct pH is about 10.2 or thereabouts. The temperature is supposed to be 38.x degrees C (I forget the exact equivalence to 100F). So, there are so many things wrong with your process I hardly know what to suspect first. Try to replicate C41 exactly first and then make variations.
Yes ok, I have got some good results at 38,7.
My Intention is to get my own negatives, with my own saturation and color density.
I solved so much, by many many tries but get stuck at the magenta cast.
But to understand why:
My greenish negatives means, that the cyan dye layer and the magenta layer is not dense enough (caused by wrong developement)? So I get redish images? And I have to find a way to get a denser cyan layer?
Or am I completely wrong?
The cyan is too dense or the magenta and yellow are not dense enough. I cannot tell without data. It sounds as if the cyan is too dense. This means too much development and too much fog.
So, you need LESS cyan and maybe more magenta and yellow.
Ad If you understand you right, in another post: a lower temperature and lower agitation cause a denser yellow?
You mean fog caused by development?
Lower temperature and lower agitation causes less CYAN or if you get the cyan up where it should be, it causes a denser YELLOW.
Remember those qualifiers. They are important.
And because yellow is the first layer on the surface of the film, maybe I can find a way to change the diffusion of the developer to the deeper layers.
Good luck on that one. I gave up due to the cost in time, film and chemicals.
The free on-line (PDF) part 5 Using Kodak Flexicolor Chemical "5 Process monitoring and troubleshooting" (Z131_05) should help you diagnose most shifts as temp/pH/time vary from spec. for c41 chemistries. The response of each of 3 color layers is plotted in graphs starting at page 5-29. With them you can see the relationship that varying each parameter has on each color layer. Most useful in figuring what/where/howmuch you want to start modifying when working with "known" chemistry. If your working at weird temps, like 25C and non-standard chemsitry, you're kind of on your own to determine each effect. I suspect the information in the manual will still be somewhat useful. Don't have the link handy, but it's easy to find on-line.
I hope I understand it right:
If the charts speak about red, green, and blue they mean the colors in the print?
Not t.E the layer on the negative that is sensitive for bue light?
t.E. ist shows an increase of RED if using to much of Part A. This means the prints will become reddish?
Red = cyan
Green = magenta
Blue = yellow
To measure the dye, you measure the "opposite" density. And, after this answer, I must say you need to do some reading real soon now.
PE's remarks are quite correct for processing errors, but outdated or poorly stored film can also cause these problems. If your film is fresh, then it is no doubt the processing.
thanks PE. I hope the books I ordered will arrive soon.
That means if the Kodak pdf speak to example about increased red color, it means that on the print that it will be blueish? That it means the opposite color?
My Film is usable till 07/2012.
I was lucy and could buy 1500 Rolls Kodak ISO 400 for only $300 !!!
They are now stored in my freezer.
The Kodak web site specifies whether it is film density or print density. In the case of control strips plotted with deviations, it is almost always film density.
And, the variations you introduced are quite a bit beyond what Kodak data covers. So, don't be surprised if you do not find the answer there.
sure it is beyond suggestion but still useful hints