Filmfan101
Allowing Ads
If you're looking for advice, first show us your results, which you think are inconsistent. Don't post finished scans, but photos of the negatives against a light background (preferably a white wall). These can be photos taken with your phone. Thanks to the white wall, the automatic WB on the phone won't go crazy.P.s @koraks i imagine you’ll have some good input cheers.
Hi, I’ve been developing C41 at home in a manual tank for about a year and a half, I’ve used the Bellini c41 kit and the Adox c41 kit but keep getting inconsistent results with both in different ways. What are people’s thoughts on best chemicals for home C41 dev. I’m in the UK so will need to be available here.
Thanks
P.s @koraks i imagine you’ll have some good input cheers.
Hi, I’ve been developing C41 at home in a manual tank for about a year and a half, I’ve used the Bellini c41 kit and the Adox c41 kit but keep getting inconsistent results with both in different ways. What are people’s thoughts on best chemicals for home C41 dev. I’m in the UK so will need to be available here.
Thanks
P.s @koraks i imagine you’ll have some good input cheers.
I’m developing in a jobo 1520 tank (120 film) using hand agitation, if people can let me know their processes when using the Bellini and Adox kits that’d be handy, I’ve been following instructions that come with the kits.
I agree with the others that in order to solve problems, it helps to understand them first.P.s @koraks i imagine you’ll have some good input cheers.
Cyan dye formation will be absolutely hampered without proper time in bleach, as is coming out of the colour developer it is very clear and forms its final coloured state in the bleach.
All I will say here is, please for your own sake do not use simple Blix kits. Use only kits that utilise separate bleach and fixer stages.
Cyan dye formation will be absolutely hampered without proper time in bleach, as is coming out of the colour developer it is very clear and forms its final coloured state in the bleach.
You may be confusing the pH-dependent color of the dye with the formation of the dye as such. The dye is really formed in the developing step, not the bleach step. pH of subsequent steps can/will affect the hue strength of the dyes, but the dyes do not chemically change after they've been formed as a result of the color coupler linking with the oxidized functional developer group.
A simple diagnostic to disprove your statement is the fact that bleach-bypass processed film has well-formed cyan dye. Overall saturation is less (across all color channels0 due to the presence of metallic silver, which acts like a bit of black paint mixed in with a color paint, which will reduce saturation (and increase density).
What I am referring to here is leuco cyan dyes
Yes, you may have to revisit those materials.This is all well documented here on this website and others, Ron himself has written lots about it over time.
Exactly; those are just completely formed dyes, but in a leuco state due to pH. Note that on modern C41 and ECN2 films, all dyes revert to a completely colored state in a simple water wash. Bleach is NOT required for the dyes to form, obtain their color etc.
This property is the reason, why the last concentrated bath (either BLIX or fixer) have to have pH within spec.
I always learned it that way. But I've also always wondered how that would work, since a non-concentrated bath (i.e. water) would negate whatever happens in the last concentrated bath, at least pH-wise. Indeed, in practice, if you wash C41 film (or modern ECN2 Vision3 film for that matter), it colors up nicely, even if it was just run through an acidic bath.
One must not mix these two up. Leuco dyes are a thing of the past, any film from the last few decades will have dye couplers and resulting dyes without that issue. The pH theme, of course, persists.
You can infer it e.g. from Rogers (2007) "The chemistry of Photography: From Classical to Digital Technologies", p68-69:Can you cite any technical publications that back such a claim?
While that publication discusses motion picture film, the overall scope of the 2-electron story is kind of broad to begin with, encompassing both film & paper, and since it relates so closely to economics (silver load), it's safe to assume that in this sense what applies to MP film also applies to stills film.Cyan couplers can belong to the naphthol family or to the phenol family (Fig. 1c). In the first case, R1 is in most cases a carbamoyl group, while in the case of phenols R1 is usually an acylamino groups, while R3 can be another acylamino or an alkyl group and R4 a hydrogen or a chlorine atom. Phenol couplers were introduced to solve the problem of reduction of cyan dyes to a leuco form, which can occur during the bleaching step where silver is removed by reaction with iron(III), leading to the formation of iron(II) which can act as a reducing agent
So that would be a nice place to start reading if you can access the relevant Imaging Science Journal issue (vol 50., issue 3).The benefits resulting from almost exclusive use of two-equivalent couplers are pointed out.
You can infer it e.g. from Rogers (2007) "The chemistry of Photography: From Classical to Digital Technologies", p68-69:
View attachment 419877
View attachment 419878
You can infer some more from Longoni et al. (2004) Chromogenic dyes in motion picture films at the turn of the 20th and 21st centuries: a multi-technique comparative study, although it discusses the related issue of cyan dye fading into leuco state in a tired bleach:
Chromogenic dyes in motion picture films at the turn of the 20th and 21st centuries: a multi-technique comparative study
The cyan, magenta and yellow dyes in a series of four chromogenic motion picture films, dating from the late 20th and early 21st centuries, were chara…www.sciencedirect.com
While that publication discusses motion picture film, the overall scope of the 2-electron story is kind of broad to begin with, encompassing both film & paper, and since it relates so closely to economics (silver load), it's safe to assume that in this sense what applies to MP film also applies to stills film.
Furthermore, Longoni et al. refer to (among others) Bergthaller (a series of 3 publications) Couplers in colour photography—chemistry and function (Parts 1, 2 and 3); from the abstract of part 1 (2002):
So that would be a nice place to start reading if you can access the relevant Imaging Science Journal issue (vol 50., issue 3).
Then there's bound to be some patent applications in the period ca. 1975-1990, but I frankly didn't probe it because it's too labor intensive.
I wouldn't. It's well-known and also confirmed by Kodak engineers that these product lines share technological commonalities. The argument that economics would be of lesser importance for C41 is quite frankly just bizarre; no company would sacrifice profitability for...well, no reason at all.I would be extremely hesitant to compare intricacies of ECN to C41.
That's quite dismissive w.r.t. that latter comment, and as to the former, you are probably referring to Ron Mowrey who was one of the people who engineered modern versions of the RA4 blix. to the best of my knowledge he never did any commercial work on a C41 blix since Kodak never released such a product, but I don't doubt he did some experimentation in that field. At the same time, we also know for a fact that plenty of people are perfectly happy with the performance of C41 blix they use at home for their amateur CN processing. I can't argue with something that works for something, even if I would have theoretical grounds for believing there's a better alternative. Much of the time, 'good enough' is perfectly acceptable.I'd be far more inclined to follow the words of the man who invented C-41 blix and hated it rather than some citing that seems largely unrelated.
That's odd because a few posts back that's exactly what you did.I wouldn't advise the use of blix because of leuco dye risk
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?