What DON'T you like about MQ developers?
I have rarely ventured past the safe, secure, pervasive genre of standard metol-hydroquinone developers because they are so good and dependable. I might tweak the MQ ratio, add some more carbonate or bromide, but rarely use other reduction chemicals like Phenidone, Amidol, etc.
Yet, there are those who swear by such alternatives. I, we, all, just might like to know why? And for prints or negatives do you choose other developers?
Perhaps the best way to approach this discussion might be to elucidate the reasons that MQ might fall short of optimal development in certain (or all?) cases. - David Lyga
Last edited by David Lyga; 12-18-2013 at 07:47 AM. Click to view previous post history.
David, your recent posts with questions on the characteristics of developers and developer constituents suggest you need to invest in a good book on the subject. There are several, and also some decent starter books. I say this because most of the answers you'll get to questions like this will be at best incomplete, and mostly incorrect, lacking any objective data or even a reasonable basis in most cases. These aberrations will be most pronounced concerning the attributes of compounds such as Amidol, Pyrogallol, PPD, etc. So with all due respect, when you ask people "why", be prepared for bad information. In my experience the people who swear by certain compounds usually have no idea what they are talking about.
In fact, the very premise of your question needs modification, as there are as many PQ formulas falling under the categorizations of safe, secure and pervasive.
A good book on the subject will help you sort out some of the important differences between developing agents - eg: how active they are at a given pH, what types of oxidation products they produce, how sensitive they are to bromide and other reaction products at different pH values, superadditivity, resistance to oxidation etc. All these things have effects not only on the working characteristics of the compounds, but on the feasibility of commercial packaging/shelf life. In addition, as has been said before, one cannot realistically discuss the working characteristics of any developing agent without discussing the rest of the developer formula. The makeup of the solution (concentration of preservative, pH, buffering, alkali choice, restrainer(s), and the presence of other developing agents) has as much, if not more to do with how the developer will work in terms of speed, grain, "sharpness", and characteristic curve shape.
So, while there are some general characterizations of developing agents on their own which can be made, these can fall away when the rest of the developer formula is added to the picture. On illustrative example of the complexity:
Phenidone (and deriviatives): on its own is a very low contrast agent, but very active (depending on pH), and poorly preserved by sulfite in solution. However add some hydroquinone or pyrogallol or even ascorbic acid, usually some bromide etc., and you can make a general purpose developer with good speed. Since Phenidone is typically less sensitive to bromide than Metol, it is said to be more difficult to formulate a "sharp" Phenidone developer, though this is not a rule.
Aside from a few attributes, generalizing about the working characteristics of any specific developer ingredient is problematic. Often the chemists/engineers themselves can't agree on what is going on.
For film development, I use Barry Thornton's two-bath which just has Metol and Sodium. It is the perfect developer for my way of working - simple, reliable and cheap. As it has worked so well for me for so long, I have not found the need to try Phenidone, Amidol, etc.
I guess I should have asked 'why' rather than 'what'. And, Michael, your proper admonition about how I should be reading up on this causes, again, 'why?' If it ain't broke, why fix it? I wonder what I am missing by staying with the MQ type? I wanted to see if others found their respective formulas better in some way. And, Michael, you are probably right in saying that 'bad information' just might be endemic to all this quest, as pride and prejudice is concomitant with loyalties, some of which are built upon mere hearsay. (Witness the fine grain craze of the 1930s). And, David Allen, I guess I was tacitly including types like D-23, metol only. Thanks. - David Lyga
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What I'd say is instead of asking "I wonder what I am missing by staying with the MQ type?", it would be more appropriate to talk about a specific formula, or at least a type of MQ developer (solvent, non-solvent etc.), or overall type of developer (general purpose, tanning/staining, etc.). Simply characterizing the type as "MQ" is too broad.
Apologies for challenging you on this - it's just too hard to answer without providing more caveats than answers. For example, generally speaking, PQ solvent developers are said to offer slightly higher film speed than their MQ counterparts. Well, ok that is sort of true in some cases, but not all. It depends. Kodak TMax developer is a PQ formulation giving more shadow detail than D-76 (MQ). At the same time, Kodak HC-110 is a PQ formulation giving less shadow detail than D-76.
There are so many variables - including the film (this is often overlooked).
OK, perhaps I was too broad with my enquiry. I have always wondered, and even tried some developers like HC-110 and Microphen; I really did not see any difference. I was wondering whether there were factors other than image quality that mattered here. I love my MQ developers too much to abandon them: ie, D-76 types but maybe with differentiation with MQ ratios instead of the '2' to '5' ratio that that developer uses. I have also used DK-50 which uses a '1' to '1' MQ ratio and even used Dektol diluted (D-72, which uses more HQ than normal for film developers: '3' to '12' ratio), however the huge amount of carbonate necessitates much dilution. - David Lyga
What do I not like about MQ?
Very simply, I do not like the temperature sensitivity of Hydroquinone. This is why I have dropped the old standards, like D76 and ID-68 and moved almost entirely to D23 and occasionally, Suzuki's DS8.
Some people get skin problems with metol I have difficult allergy problems anyway so don't take the risk normally.
When printing with trays I use inspection gloves.
C41 dev all the time.
I normally temper at 20C from dev to final wash.
Not really detected any differences between D76, Microphen and ID68, and I like the grain in Rodinal type soup.
When I make up D76 I use a boric acid/borax buffer if Im using a stock bottle otherwise 1 to 3.
Developers with hydroquinone can change activity over time. I don't see too many complaints on APUG about this, but I have experienced this myself and so tend to avoid such developers. For film. I like D-23 and for paper the variant of Ansco 130 without hydroquinone. Of course, there are others probably as good or better.