ManuelG
Hi everyone,
I’ve got a really basic question: how do I perform the dilution of the stop bath properly?
To be specific: the instructions for ADOX films say you should stop with a maximum of 2% acid. But how do I work out the right concentration? I’ve bought Adostop, which the catalogue says has a concentration of 60% (incidentally, there’s nothing on the bottle!). It also says you should perform dilution of 1+20 to 1+40 for films.
But how do I work out the 2% acid concentration? I’ve already searched online but haven’t found anything useful...
Or is it so simple that I’m overcomplicating things???
Kind regards,
Manuel
Gerd
60% / 40 = 1.5%
Gerd
mdeutgen
Hi everyone,
I’ve got a really basic question: how do I achieve proper dilution of the stop bath?
To be specific: the instructions for ADOX films say you should stop with a maximum of 2% acid. But how do I work out the right concentration? I’ve bought Adostop, which the catalogue says has a concentration of 60% (incidentally, there’s nothing on the bottle!). It also says you should perform dilution of 1+20 to 1+40 for films.
But how do I actually get to a 2% acid concentration? I’ve already searched online but haven’t found anything useful...
Or is it so simple that I’m overcomplicating things???
Kind regards,
Manuel
Manuel,
It’s quite simple to work out: I have a 60% stock solution and want to end up with a 2% solution. If I take a portion of the acid, I just need to ensure that this portion corresponds to 1/30 of my final solution, so I need to multiply the quantity by thirty. I already have one part, so I still need 29 parts. Result:
60% acid in batch 1 + 29 gives a 2% working solution.
By the way, I’m currently only using a stop bath because I have a neutral fixing concentrate at the moment; otherwise, I do an intermediate rinse and skip the stop bath. When I do stop the process, however, I use citric acid in powder form (one tablespoon per litre of water) from the chemist’s; I’ve got some lying around in the kitchen anyway for descaling various utensils...
Martin
ManuelG
Hi,
Thank you so much for these helpful tips :) Sometimes you really do end up going round in circles. I could have worked that out myself :unsure:
As for the stop bath itself: I realise you don’t necessarily need it, but as I’d already ordered a load of stuff from Impex, I just added it to the list. The few euros don’t really matter given the overall cost. After all, the bottle costs about the same as a 4x5-inch E6 development here at Brieke...
Best regards,
Manuel
cfb_de
Ladies and gentlemen, dear forum members,
I am constantly shocked by how little knowledge there is of the rule of three. After all, this is something taught in Year 7 or Year 8, depending on the region.
That is why I am not at all surprised that the Trade Inspectorate is taking action against the sale of selenium to hobbyists. Anyone who clearly does not master the rule of three is not fit to handle chemicals that are harmful to health (according to the strict definition, this thin swill is not actually ‘toxic’).
That said, I find this crackdown by a single regulatory office rather ridiculous and the reasoning behind it highly questionable; it certainly doesn’t originate with me, but comes from elsewhere.
I shall reconsider my expert philosophy in the interests of greater customer safety. It could well mean that no other developers may be sold on Rümpeliges Kaffee. Nationwide!
“Your chemist will be happy to prepare the developer formula for you.” Bravo. In terms of knowledge, we’re heading right back to around 1850. “The Baleks’ Scales” and all that entails. I chose this literature almost by chance after reviewing the analyses of common photographic chemicals available to me and comparing them with the marketing claims of their manufacturers/sellers.
No, I’m not doing that. But this is precisely the scenario awaiting all analogue photographers if they don’t finally learn to master their tools of the trade (including the rule of three, cleanliness in the darkroom and reading instructions – that’s enough) and still want to pass themselves off as “knowledgeable” by virtue of their experience in the craft.
Manuel, you’ve just happened to fall victim to my rant. Unfortunately, you’re not alone and find yourself in dubious ‘good company’ with various master and journeyman photographers. Eighty per cent of them didn’t understand a thing during their training and probably slept through every lesson at school.
Right. I just had to get that off my chest. How am I supposed to help any of us if I’m being shot right in the kneecap like this? Pippi Longstocking (“Three times three is nine widewiddewid and four makes ten!”) isn’t much help here. Although, as we all know, she can carry horses on her shoulders.
Best regards,
Franz
mdeutgen
Franz,
You’ve put into words what I didn’t dare to write myself.
In my view, what you’ve raised has now become a fundamental problem in society; I see it time and again in my work too: people no longer know the simplest things and just stick to the formulas laid out in instructions. Unfortunately, understanding the ‘why’ has taken a back seat. I can recall that during my training I also had in-house lessons and our trainer tried to explain the rule of three to us. After an hour, I discreetly pointed out to him that something couldn’t be right with his formula (‘two halves of something’ was suddenly more than before).
I learnt my lab skills from my grandad (no, not the one with the Füllfix this time, although he was a master of his craft – it was the other one’s turn), and that was based on the principle of “learning through understanding”.
What I wrote in my post above was essentially the line of thinking my grandad used to explain it to me (and would have done so), and it doesn’t require any fancy training; sixth-grade knowledge is perfectly sufficient for this.
However, I must also take a stand for Manuel here: he’s unsure and asks for help! Many others would simply start cobbling something together and then launch into rants because it doesn’t work, but refuse to admit that they don’t know.
I, too, ask questions on the forum from time to time, because there are simply those days when you can’t see the wood for the trees!
Martin
ManuelG
I also ask questions on forums from time to time, because there are just those days when you can’t see the wood for the trees!
That’s exactly how I felt last night, thanks. If I’d had a good night’s sleep this morning, I’d probably have worked it out myself, but I just wanted to know last night. So I asked here. Which brings us to the second point:
However, I must also take Manuel’s defence here: he’s unsure and asks for help! Many others would simply start cobbling something together and then launch into rants because it doesn’t work, but refuse to admit that they don’t know.
I thought that’s exactly what forums are for: to share experiences. And that’s certainly worked out.
And now to the residue of the ‘tirades’: I was really surprised by such a reaction to what was (apparently) a simple question. You have no idea who I am, what I do, or any other information about me. And yet I’m being lumped together with incompetent master photographers and the like, and having the frustration of society’s stupidity vented on me—which is somehow frightening—simply because I didn’t realise last night that a simple rule of three would solve my problem.
I have certainly developed films before (the first ones under supervision in the school lab – it’s been a while) and reading technical specifications and logical thinking are not alien to me either...
I don’t feel personally attacked, but I don’t find the way a question from a forum newcomer is being responded to here particularly appropriate. That sort of thing doesn’t make a good impression on newcomers. Insinuations that I slept through school and the like are a bit off the mark. I just wanted to get that off my chest.
Kind regards,
Manuel
cfb_de
Hello Manuel,
I actually thought it had been made clear enough. My comment wasn’t directed at you, but simply at this unfortunate state of affairs these days.
We’re dealing with people like you, who are good enough to ask first. Very good! Unfortunately, this makes the higher authorities and their officials feel the need to intervene, thinking, ‘They’ve no idea what they’re doing and need to be protected by us’.
And then we have to deal with the complete idiots I’ve already mentioned—the 80% of them—who operate under the motto “that’s how we’ve always done it”. Some of them even knowingly breach hazardous substances legislation without sufficient qualifications, and leave commercial customers (who are also without sufficient qualifications) holding the baby. Unfortunately, in hazardous substances legislation, as almost everywhere else, the ironclad principle of “the last ones get bitten by the dogs” applies. These are the customers and end-users.
Unfortunately, such honest questions these days are grist to the mill for those who, with do-gooder intentions, want to ban everyone from handling chemicals. If I were to publicly announce today that I chemically reformulate sucrose and add the product to my liqueur, some official from the authorities would shut down my liqueur business. Unfortunately, they don’t realise that it is nothing other than industrially produced ‘invert sugar syrup’, as legislation is now clearly geared towards industry. At home, I’m not allowed to add even two drops of sulphuric acid to 100 litres of cane sugar solution and then bring the whole thing to the boil.
These well-meaning law enforcers usually have a very good theoretical grasp of the implementing regulations, but tend to lack practical expertise. And they’re quick to make a mountain out of a molehill, as we can currently see with the Selentoner issue.
As a freelance state-appointed expert, this really pisses me off twice over. When higher authorities, without applying their own expertise, rigidly adhere to implementation regulations that are poorly formulated from a technical point of view. There used to be a technical term for this when it came to the judiciary. This now has its counterpart among the supervisory authorities: legal positivism.
Solely for the sake of my own peace of mind, I have been considering returning my expert appointment for years. However, that would be tantamount to surrender.
Best regards,
Franz
mdeutgen
Hi there,
Please excuse me if this thread is straying a bit from the original question, but I’d still like to respond to Franz’s post. The same applies to me: I hope I’ve been able to provide the answer you were looking for in a way that’s easy to understand, and I haven’t made any judgements about the questioner’s education. That’s not my place, and I’ll be careful not to do so.
Nevertheless, I too must express my bewilderment at how much knowledge about certain things has declined in our society. Admittedly, knowledge as a whole has multiplied exponentially in recent years, and when I think back to my A-levels, I doubt I’d pass today’s exams with the knowledge I had in 1988... The amount of knowledge required has increased to such an extent that, in my view, it is no longer possible to know everything. Here’s an example: Last Friday I was out buying trainers for my two boys again, and in our town you can hardly find any lace-up shoes anymore, as the local nurseries insist on Velcro fastenings. Back in my nursery days, the rule was: ‘You’ve come to nursery, so first of all you’ll learn how to tie a bow’. Well, I didn’t start nursery until I was four, not three as is common today – perhaps that’s why.
And I think this is where the problem lies: basic skills are no longer taught, and due to this lack of expertise, the civil servant described by Franz clings to his implementation guidelines for a regulation, for at least two reasons:
1. He is unsure about the matter and shies away from making a decision.
2. If he applies the implementation guidelines rigidly, he’s on the safe side and off the hook when it comes to liability, because ‘that’s what it says’.
(Why is Gert Fröbe in ‘The Daring Men in Their Flying Machines’ popping into my mind right now?? I’m just saying RUMPELSTOLZ!)
I may not be as up to speed on the latest developments in chemistry as Franz, but the experience I’ve gained at the recycling centre and with our waste disposal is enough for me. When I phoned to ask how I could dispose of fixer, I was told that as a private individual (i.e. a non-commercial user), I was allowed to hand in 35 kg of hazardous waste per day. So I asked further whether I could then take my 5-litre canister back with me, and suddenly they said that would then be a commercial quantity.... So I asked again, what about, for example, binder paint, which is, as is well known, also available in DIY stores in containers of 10 to 12 kg. Then it suddenly worked out again after I explained to the lady that fixers are also available as a concentrate in 5-litre canisters. (I then seriously wondered whether the lady had any idea of the volume of a 5-litre canister and could imagine what 35 kg actually is.)
And this is where I see the great advantage of forums. You get the missing information explained directly, or you can ask if you’re not sure whether you’ve understood something correctly.
To make it clear once again: I, too, ask questions from time to time because there’s something I don’t know or I’m unsure about. It’s inevitable that I’ll occasionally get a few replies from self-proclaimed know-it-alls, but I make a point of skimming those over.
Martin
ThomasLoos
As an independent state-appointed expert, this really gets on my nerves. It’s infuriating when higher authorities blindly stick to implementation regulations that are poorly worded from a technical point of view, without applying their own expertise. There used to be a technical term for this when it came to the judiciary. This term now has its equivalent among the supervisory authorities: legal positivism.
Hello!
I agree with you completely in principle and think it’s good that you’ve put this into words with your typically sharp wit.
I can’t stand the fact that more and more people are stupidly learning some technical, short-term, practical stuff, whilst general knowledge and basic understanding are increasingly being pushed to the back burner. All under the banner of ‘the economy demands it’ – we are training more and more robots and fewer thinking human beings.
On one point, however, I disagree with you, since we’re already off topic: that is not legal positivism. In a constitutional state, it is simply the case that authorities must not place themselves above the law, and that is a good thing.
The problem lies elsewhere, and we lawyers (except those who are equally incapable of thinking – there are plenty of them too) suffer massively as a result: there is an insane and nonsensical flood of laws and regulations being enacted at breakneck speed without much thought or understanding. And all of this is of poor ‘technical’ quality. This is a massive failure of politics and affects the whole of Europe. Ultimately, it harms precisely what we want; it harms our constitutional structures. In any case, it is not only legal experts who are annoyed by this; everyone involved in anything legal is annoyed by it.
The second point is: the whole situation is exacerbated by the fact that – and here we come full circle – it is primarily first-instance authorities that do not understand the existing regulations and laws themselves and misinterpret them – why? Because they lack the necessary qualified staff with a general legal education. They have practically only specialist staff, and these tend to take individual regulations out of their overall context (which they are unaware of), stick to the letter of the law and misinterpret them – and usually in a far more bureaucratic manner than would be legally correct.
So, now I’ve got that off my chest...
Best regards, Thomas
cfb_de
Hello Thomas,
There is one point on which I disagree with you, though, since we’re already off topic: that isn’t legal positivism. In a constitutional state, the fact is that authorities are not allowed to place themselves above the law, and that’s a good thing.
You’ve very cleverly managed to spot the sole instance of the heavy sabre amidst my foil thrusts :unsure:
But that’s exactly the point: junior civil servants are now once again automatically accepting the biggest load of rubbish as absolute truth without questioning its substance, and are rushing headlong into the future in pre-emptive obedience.
Right. Strictly speaking, the term I’ve chosen actually refers to lawyers who have long since passed away. The essence of the matter remains the same, however, especially as the official chain of command functions far more consistently today than protective custody did in the (German; I don’t know how it was in your country) Empire.
Best regards,
Franz
