Increased contrast with hydroquinone is also found with metol as illustrated in p173-177 here:I don't have that paper available, but taking the quote at face value, isn't he comparing metol in MQ developers with phenidone in PQ developers?
I've been pondering the question posed in the title of this thread (Would I be missing anything if I use D-23 instead of D-76?). It almost boils down to 'What did hydroquinone ever do for us?'
My experience of metol-only development is chiefly with Thornton's 2-bath formula. For the vast majority of scenes, I get negatives that print straight or with minimal manipulation on grade 2 or 2 1/2 (Ilford Multigrade Classic). If they don't, it's usually because I have cocked-up the exposure. So why would I need more contrast? If I was routinely having to use grade 3 or higher, I might understand, but that's not the case.
My cynical alter-ego would like to believe this, but the Ilford Manual of 1958 (revised 1966) specifically said, "The success of these mixtures depends upon the fact that their photographic properties are superior to those of the components taken separately" [my emphasis]. Is the explanation that in 1966 emulsions needed that extra contrast, whereas with today's emulsions we don't really need hydroquinone but it makes good manufacturing economics?Price! Based on my current chemical sources, if I set the price of 100g phenidone at 100, the price of metol is only slightly lower (approximately 95), hydroquinone is about half the price (around 45), ascorbic acid (chemical grade) is roughly one-seventh (about 15).
On the Photoformulary, phenidone 10g is $14.95, metol 100g is $16.95, hydroquinone 100g is $8.95, and ascorbic acid 100g is $12.95.
While prices vary by location and package and grade, it is clear that, when producing and packaging in large quantities, using 2g of metol plus 5g of hydroquinone is significantly more cost-effective than using 7.5g of metol alone. Manufacturers like Kodak would seek to reduce raw material costs wherever possible, if they can provided product quality remains unaffected.
Sure, yes, I have that book and I understand about super-additivity. But my question was, why do we need that extra contrast if in most circumstances metol alone produces a negative that prints on Grade 2 or 2 1/2?Increased contrast with hydroquinone is also found with metol as illustrated in p173-177 here:
Developing The Negative Technique : Kurt I. Jacobson, Ralph Eric Jacobson : Free Download, Borrow, and Streaming : Internet Archive
Eighteenth edition, revised, updated and reprinted. Epson V750, Vuescan, ScanTailor, Adobe Acrobatarchive.org
Sure, yes, I have that book and I understand about super-additivity. But my question was, why do we need that extra contrast if in most circumstances metol alone produces a negative that prints on Grade 2 or 2 1/2?
My cynical alter-ego would like to believe this, but the Ilford Manual of 1958 (revised 1966) specifically said, "The success of these mixtures depends upon the fact that their photographic properties are superior to those of the components taken separately" [my emphasis]. Is the explanation that in 1966 emulsions needed that extra contrast, whereas with today's emulsions we don't really need hydroquinone but it makes good manufacturing economics?
Sure, yes, I have that book and I understand about super-additivity. But my question was, why do we need that extra contrast if in most circumstances metol alone produces a negative that prints on Grade 2 or 2 1/2?
if a formula calls for 3mg of something in 1L solution—if I have to mix 500 ml new solution each time, I may rather use a formula that doesn't require such precise measurements
Dektol is a pretty nice developer for film, also.
I used to use Microdol-X [1:3] for Panatomic-X ...
True -- I only contact print w/ alt processes. However, a friend scanned the 4x10 negative of the above girders and made a 7 foot long inkjet print of it for a show. I just took a look at the print (it's been a few years!) and the grain is definitely not course, but the exact structure is difficult to tell in the print. Things are a little too disorganized around here right now for my to easily grab the negative.Especially if fine grain isn't a primary driver.
I only contact print w/ alt processes.
But it's cheap, dependable, and doesn't ever seem to go bad.
Crawley ,BJP Dec 16 1960 p684 explained this.
"The presence of metol also assists discrimination in the highlights, which in some PQ developers are liable, the author finds, to 'run away'."
In other words, hydroquinone gives a more contrasty negative.
.........................
The exception is where Kodak and Ilford used Pyrogallol as an Oxygen scavenging agent in two MQ deep tank developers, and their replenishers, in the 1930s.
Ian
My answer to this question is "no" but there is an important detail. You did not specify which would be your sources of metol and sulfite if you decide to make D23 from scratch. If you already have a digital microscale, for the same amount of money you could get a cheap pH meter. Buying a commercial D76 or ID11 has the advantage of quality control for ingredients, while your scratch mixing needs that too, if only in the form of controlling the pH of the developer. Sodium sulfite is particularly suspect chemical, and you may encounter one that is substantially contaminated by residual sodium carbonate. You D23 would then have a substantially higher pH than intended (pH ~8). It will not only develop faster, it would have a tendency to over-development with larger grain, and it will also have a shorter storage time, all other conditions being equal.I've ordered a 1L kit of D-76 and I am looking forward to developing film with the gold standard developer. That will help establish a baseline of what a developed film is supposed to look like.
But... Long term, I'd rather use developers that I can mix myself or are concentrates that never go bad. That would better suit the sporadic & random nature of my photography hobby. I have Rodinal, PC-TEA, and the ingredients & tools (e.g. milligram scale) to mix D-23 in small batches. I know that Rodinal (and I think also PC-TEA?) will give a different look to D-76 because D-76 is a solvent / fine-grain developer. But D-23 is also a fine-grain developer. D-23 is apparently a lower contrast than D-76, but my understanding is that contrast is something I can learn to control with over/under exposure and push/pull processing.
Is there any reason it might not be a good idea to use D-23 as my single fine-grain developer?
My answer to this question is "no" but there is an important detail. You did not specify which would be your sources of metol and sulfite if you decide to make D23 from scratch. If you already have a digital microscale, for the same amount of money you could get a cheap pH meter. Buying a commercial D76 or ID11 has the advantage of quality control for ingredients, while your scratch mixing needs that too, if only in the form of controlling the pH of the developer. Sodium sulfite is particularly suspect chemical, and you may encounter one that is substantially contaminated by residual sodium carbonate. You D23 would then have a substantially higher pH than intended (pH ~8). It will not only develop faster, it would have a tendency to over-development with larger grain, and it will also have a shorter storage time, all other conditions being equal.
Similarly, making D76 from scratch has the same caveat. Its pH should be 8.6 to 8.8, otherwise the same set of problems will be encountered.
Here I am deliberately not getting into what is fundamentally bad about both developers.
Are these problems with purity true of all home-made developers and if not which home made developers are free of these defects?
I would argue that any popular homemade developer must, almost tautologically, have little enough variance to have many happy users.
My answer to this question is "no" but there is an important detail. You did not specify which would be your sources of metol and sulfite if you decide to make D23 from scratch. If you already have a digital microscale, for the same amount of money you could get a cheap pH meter. Buying a commercial D76 or ID11 has the advantage of quality control for ingredients, while your scratch mixing needs that too, if only in the form of controlling the pH of the developer. Sodium sulfite is particularly suspect chemical, and you may encounter one that is substantially contaminated by residual sodium carbonate. You D23 would then have a substantially higher pH than intended (pH ~8). It will not only develop faster, it would have a tendency to over-development with larger grain, and it will also have a shorter storage time, all other conditions being equal.
Similarly, making D76 from scratch has the same caveat. Its pH should be 8.6 to 8.8, otherwise the same set of problems will be encountered.
Here I am deliberately not getting into what is fundamentally bad about both developers.
The fact that sulfite quality may be variable is known since the beginning of the 20th century. The first mention known to me comes from a book of Baron von Huebl “Development of plates with uncertain exposure” of 1919.So depending on the purity of the sulfite which may be suspect for the reasons you give but will be unknown to the user the dev time for D23 varies as does its speed
If my conclusion from your above quote is correct, what might be the range of speed and dev times encountered
Can I also ask whether you found this to be case in your use of D23 and what might be the frequency of the problems, assuming such problems arise
Are these problems with purity true of all home-made developers and if not which home made developers are free of these defects?
Thanks
pentaxuser
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