heinrich
Hello Mirko,
I have the following questions about Adofix:
Does the fixing time of 1 minute specified for photographic paper at a dilution of 1:9 also apply to baryta paper?
How short is the fixing time at a dilution of 1:4?
Best regards,
Heinrich
MirkoBoeddecker
Heinrich,
These figures are guidelines and minimum fixing times.
In specific cases, you’ll naturally need to adjust this.
Take baryta paper, for example, especially if it has a thick base. Glossy surfaces also need to be fixed for longer than matt ones.
I fix for 4–6 minutes at 1+9.
It also depends a bit on the temperature.
Best regards,
Mirko
heinrich
I fix for 4–6 minutes at a 1:9 dilution.
It also depends a bit on the temperature.
Hi Mirko,
....4–6 minutes at 1+9 – honestly, why do you then specify 1 minute as the standard fixing time for 1+9? That can’t really be right. Does that mean you don’t trust your own specifications? It’s clear that layer thickness and temperature play a role, but does that really account for a factor of 4 to 6, or are you fixing at 15°C? I’ve already set the fixing time to 2 minutes just to be on the safe side; now I can decide whether to re-fix the stack from last weekend. Do you realise what you’re doing to me?
If even the fixing time specifications have to be interpreted flexibly, what about the specifications regarding yield?
Before things get heated, the 4 minutes for films works out quite well, at least for HP5; the clearing time is 1 minute 30 seconds. After 20 sheets of 24x30 baryta, the rinsing time is then around 1 min 45 sec, so not much changes there (2.5-litre batch).
Regarding temperature: I’m referring to the Duka standard of 20°C.
Regards,
Heinrich
Gast
Who still remembers?
2001/2002 Catalogue
"Classic Pan 400 is a [color="red"]rock-solid [/color] film with a classic grain structure, a wide range of speed and exposure latitude, and [color="red"]fine [/color] grain.
heinrich
Hello "Reminder"
... who’s going to start picking at old wounds? A bit of noise is part and parcel of the trade if you want to sell your products; otherwise, you’ll go bust in no time... and I wouldn’t wish that on anyone
But the claim that the fixing time is 1 minute really does annoy me... :angry:
But let’s wait and see what Mirko has to say about it.... <_<
As the professional link between the customer and the company, I know the problem all too well: on the one hand, the sometimes untenable marketing claims; on the other, the customer’s expectations. Sometimes I could give both sides a good thrashing...... one lot spouts nonsense, the other lot believes everything.... this time I’m the customer and have to ask myself where I left my brain......
With that in mind
Heinrich
Gast
Who still remembers?
2001/2002 Catalogue
"Classic Pan 400 is a [color="red"]rock-solid [/color] film with a classic grain structure, a wide range of speed and exposure latitude, and [color="red"]fine [/color] grain.
I don’t understand that at all. What does that have to do with the fixer issue?
cfb_de
Guys,
just sit back and relax.
*Basically*, the aim of fixing is to ensure that it is carried out *adequately*. Ideally, this should remove *all* unreduced silver ions from the emulsion.
That would be correct. It’s likely that 99% of all lab technicians simply can’t get this simple thing right in the lab. (Even though the ‘Küzeit test’ for films, the ‘rinse test’, the ‘KI test’ for checking the suitability of the fixer solution, and so on, have been standard lab techniques for around 150 years.)
And that is the sole reason why – unfortunately – we still have these mindless package leaflet instructions regarding “times” for a “recommended” dilution.
In real life, you test this using the available analytical methods and have no reason for queries or complaints. In the case of film fixing, the ‘available’ analytical methods mean determining the fixing time (and doubling or tripling this for the film to be fixed), the “KI test” to determine the basic suitability of the solution (which can optionally be replaced by test strips that are many times more expensive, albeit with poorer results), and a regular test for silver and iodide content in paper fixing.
Anyone who cannot do this is, as far as I’m concerned, welcome to perform a dilution of any old fixer 1+1 and use it as a single-use batch for archival-quality fixing. Develop crisply (baryta for a maximum of three minutes in Eukobrom; applies to Polywarmtone), stop quickly (4% citric acid, 30 sec) and then fix for two minutes in 1+1 (I use Amaloco-X55 for such extreme processes)... This survives 100 hours in a solarium without visible change.
The baryta paper remains firm; three times two minutes in water is sufficient for complete rinsing. True to Wollstein’s motto: “Fix intensively, rinse briefly”.
However, I do not adhere to these costly ideal processes either. I fix with Superfix 1+9 or X55 1+7 for baryta for approx. four minutes. But I also monitor the silver/halide content through regular titration/gravimetry and tend to rinse for far too long afterwards using a sulphite bath.
On the subject: for me, a classic film is the Efke-50. HP5+ is modern rubbish – but I still like to use it.
Best regards,
Franz
WolfgangMoersch
Heinrich,
It’s actually more a case of taking it easy. As a ‘competitor’, my assessment should be above suspicion from a marketing perspective. Adofix is one of the strongest concentrates on the market. Ideally (fresh solution, constant agitation), one minute is sufficient for most papers; I would only allow a little more time for the PWs. The two-bath method is safer; if space doesn’t allow for this, and you’re dealing with a high throughput, I’d recommend collecting the prints in a water bath and then giving them a brief treatment in a fresh solution before washing.
A drop (generous) of selenium or sulphur toner (whether thiourea or stink toner) on the unexposed edge of the image will show within seconds what the situation is.
Regards
wm
MirkoBoeddecker
Actually, Franz and Wolfgang have already covered everything.
Different materials require different processing times.
That’s why the Adofix bottle states: ‘The times given are minimum fixing times at 20°C’.
It also mentions the capacity, as that’s a factor too.
Nothing ever works in the darkroom without testing. All times are always just guidelines.
In my experience, with my 4 minutes, I’m ‘definitely on the safe side’ when using silver-based baryta papers.
Whether the same result is achieved after just one minute would need to be tested in each specific case. It also depends a bit on how much you move the paper.
I move very gently – that’s why I need longer.
By the way, Superfix isn’t more concentrated or faster than Adofix, and they specify 30–60 seconds.
They don’t differentiate there either between PE, baryta, heavy card, double weight, etc.
In my opinion, nobody does that.
Regards,
Mirko
P.S. Fixing for too long isn’t good either, as it damages the highlights.
Shall we start a long discussion now about what’s better – rather short fixing times or possibly too long....
MirkoBoeddecker
classicpan: As far as the formulation is concerned, no manufacturer anywhere uses negative descriptions for their products.
No one would describe TriX as coarse-grained and Tmax as fine-grained; instead, one is described as relatively coarse-grained, whilst the other is described as having fine grain or the finest grain.
The classicpan has a fine grain because it is cast as a multi-layer film with fine and larger grains in two emulsion layers. There are significantly coarser-grained films with 200 or 400 ASA.
The important thing is that the reader understands which film has a fine grain or a coarser grain than the other. I have actually made an effort to describe this as clearly as possible.
mirko
heinrich
Hello everyone,
For those of you who aren’t in the know, please see
@cfb_de: what is an “AI test”?
@ Mr Moersch: what happens if I drip a thick selenium or sulphur toner onto photographic paper that hasn’t been fully fixed?
Best regards,
Heinrich
Gast
About Classicpan
There are films with much coarser grain, rated at 200 or 400 ASA.
Yes, please, which ones? The ‘original’ FORTE 100 is already a grainy mess; the 400 is already too coarse for some GF users.
cfb_de
Hello Heinrich,
"AI test" refers to the quick test of the fixer using a potassium iodide solution.
I’ll quote “Junge/Hübner” (though I do things slightly differently myself):
<START>
An indication of the content of silver compounds and sodium thiosulphate is obtained by adding one ml of a 5% potassium iodide solution to 10 ml of fixer (test tube). If no precipitate forms, the bath is perfectly fine. If, after further use, the yellowish precipitate consisting of silver iodide that forms is dissolved during shaking or shortly afterwards, this is a sign that the silver content of the bath is sufficiently low and the sodium thiosulphate concentration is still high enough. If the precipitate remains undissolved or only disappears after prolonged shaking, this is a sign that the bath is exhausted.
<FINISHED>
I have the following comments on this:
- This naturally also works with ammonium thiosulphate fixers.
- It is purely a quick test for silver ions (i.e. *not* to check whether there is still enough thiosulphate in the solution; on this point, Messrs Junge and Hübner are mistaken!)
- This test often fails with film fixers (flat-crystal films); films themselves often contain huge amounts of iodides.
Best regards,
Franz
WolfgangMoersch
@ Mr Moersch: what happens if I drip concentrated selenium or sulphur toner onto photographic paper that hasn’t quite finished developing?
Well, it tones – where there shouldn’t be anything left to tone.
If nothing happens, all is well. If a veeeery faint tint appears, it may be the base fog becoming more pronounced (because it is coloured); however, if the density (of white or light grey) increases very noticeably, this indicates that undissolved silver salts are still present and visible silver selenide or silver sulphide is forming. If such a print were toned in the usual way, the edges of the image would become blotchy. If it is not toned, it simply takes a little longer for sulphur compounds to form. If detected early enough, the problem can be addressed.
The gentle approach: re-fixing
A radical cure for the worst cases: very strongly diluted bleach (hexacyanoferrate) for 30 to 40 seconds, rinse briefly, 15 seconds in fixer, and the whites are clean.
I cannot provide exact dilution instructions for commercially available bleach solutions, as the concentrations vary too widely. I perform dilution of my bleach to 1:800 for this purpose. For pure hexacyanoferrate solutions, 0.25 to 0.5 grams per litre of water should suffice. With a ‘properly’ diluted bleach solution, the highlights are not yet affected.
To pre-empt the question, “why not Farmer’s”: with such a strong dilution, the developer (hexacyanoferrate + thiosulphate) would be completely used up after the first print, and could therefore already be ineffective by the next print.
heinrich
Hello everyone,
Thanks to Mr Moersch and Cfb_de for the detailed information
Best regards,
Heinrich
