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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.
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