Photo Engineer
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Sandy;
Thanks. I see that you are doing the same in your efforts. Best wishes.
PE
Thanks. I see that you are doing the same in your efforts. Best wishes.
PE
Have you actually read Crawley's extended 1960/1 article Ron, or seen the formulae listings in the BJP Almanac's and Annuals he edited.
Unlike Bill Troop, Crawley didn't purport to have inside knowledge from any company in his original article, he merely examined some of the then commercially available developers. Kodak developers have been published over many years in the BJP, in fact the BJP pre-dates Kodak by roughly 30 years, and began publishing Kodak formulae when they were first release, I'd guess from around 1900 onwards. Crawley merely continued to publish the Kodak formulae that were already listed (which happen to be the ones in question), and they don't differ from the Koadak Formulary.
Crawley wasn't interested in what variations Kodak had in research files back then (1960/1) but rather in devising what he thought then were state of the art formulae. He had started the publication of formulae in the BJP all companies released formulae for publication. In another thread someone mentioned that Kodak didn't start selling chemistry until 1938, I've no idea how true that is but in their UK adverts in the BJP everything for Photo-finishers is listed except chemistry, and Australian/New Zealand branch has none either (separate adverts), in fact no pre-packed chemical at all.
In many ways Crawley is mainly useful for his writings in a more general sense and observing how he tackled developer design. His name was only introduced into this thread because Bill seems to attribute the 3.1/5.9 weights etc to him, while they were in fact Kodak's own weights, and very widely published.
Lets leave Crawley aside as he's totally irrelevant in the differences with the rounded off formulae and played no part in them, if or when Kodak published formulae they have to be accepted as being correct, after all they are primary sources of data.
The fact that a great many Kodak formulae have been published by others with the Metric weights rounded off means that they aren't strictly accurate and we have to accept that the original Kodak weights are in fact historically correct for the formulae.
Ian
Finally, Ian, why not pick on Kodak instead of me? In all the publications I have seen from the 70s and 80s, Kodak always printed D-61a correctly. I do not of course take credit for this, but am glad to note they got it right in the end.
Ian, nothing you say takes away from the simple fact that Crawley published his own conversions from avoirdupois. He did the maths himself. ?
Ian;
Avoirdupois measures vs Metric (rounded up or down) in the cases I compared do not match correctly.
PE
I checked the Metol, Hydroqinone, Bisulphite and Bromide of the Kodak Resaerch Formulary (Harrow) & also the UK Chemicals and Formulae and converting the Avoirdupois weight to metric all 4 were accurate conversions to around 0.01 of a gram.
The key for some reason seems to be the Avoirdupois weights. It makes sense to round off the metric figures for simplicity but you are losing Kodak's original accuracy.
Ian
LA Mannheim, a hack for Kraszna-Krausz who was responsible for as much misinformation as most Focal Press authors?
Ian;
Two formulas quote Metol as 3.0 and 45 grains vs 3.1 and 45 grains. This should be 3.0/45 = 3.1/x or 46.5. With comparable rounding this should change to 47 grains or be printed at 46.5 grains.
If you go the other way or 3/x = 3.1/45 you have 43.5 or 44 grains. (this back and forth is to show what either Crawley or Russell or both may have done (IDK). This is a variation of from 47 - 44 grains. The English is not being treated properly. This happens over and over in these formulas.
Something is wrong no matter how you look at it. I have found this in several textbooks which say one thing and do another in the table.
PE
KRL only, ever formulated in metric
Except of course Jacobson & Mason etcthe chauvinistic trip? Nobody, nobody, nobody, has done more for British photochemistry than me.
Ian;
Two formulas quote Metol as 3.0 and 45 grains vs 3.1 and 45 grains. This should be 3.0/45 = 3.1/x or 46.5. With comparable rounding this should change to 47 grains or be printed at 46.5 grains.
If you go the other way or 3/x = 3.1/45 you have 43.5 or 44 grains. (this back and forth is to show what either Crawley or Russell or both may have done (IDK). This is a variation of from 47 - 44 grains. The English is not being treated properly. This happens over and over in these formulas.
Something is wrong no matter how you look at it. I have found this in several textbooks which say one thing and do another in the table.
PE
So which is right, well to find out you need to know exactly how many grains are in a gram, and make sure that your dealing with the right liquid measure for the final developer.
One grain is actually 64.79891 milligrams, as defined by SI, so 45 grains would be 2,915.95095mg or 2.91595095 g so both versions are actually wrong. 3,0g would be 46.297075059 grains.
However if you assume that the grain measurement was in US liquid quarts (there are 1.0566882094 quarts in a Litre), and the grams in Litres then 3.0g would be 43.813373375 grains, still wrong, now lets use the 3.1g version it would be 47.840310894 grains per Litre or 45.265513689 grains per US quart. You could round that off to 45 and be close enough.
There are lots of places where a conversion could go wrong, especially if you were doing the math by hand and didn't keep all the decimal places.
Ron's explanations are likely to be close to the mark and also match what I've said many times in the thread, so the implication is that the early versions of the Formulae were right. Ron has at no stage said or implied that they would be wrong.Bill, Ian;
I'll tell you how decimals get added.
The original formula may specify 5 g/l of X in a fresh mix. It goes to the plant and they make the formula and find a 10% loss or a 10% variation in sensitometric result after the first day but it is ok after that, so they play with it to get the right (R&D) result. Lets say it takes 5.1 grams of X to make the formula rock stable but it is a little high on the first day. This might represent what is seen with D-76 in actual practice AAMOF.
This can also be seen in formulas like D23 and DK60. It can be seen in D76R, and in a number of other places where the English and Metric formulas both use fractions in compounding the developers. Formulas that use fractions of units in both English and Metric seem to me to be more likely to be right. IDK but that is another opinion.
PE
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