My guess is they would be developed very very close to the grain they come from. Whatever happens, they don't seem to make it into the developer tank, and development on the emulsion surface would show up as dichroic fog.
My guess is they would be developed very very close to the grain they come from. Whatever happens, they don't seem to make it into the developer tank, and development on the emulsion surface would show up as dichroic fog.What happens to these silver sulfite complexes that remain in the emulsion? Are they removed by the fixer?
........., I guess I've just got used to using Pyrocat HD I like the results I get with it, I find the negatives print easily. It's no better than Xtol and equally it's no worse, it's just a different approach using a staining developer.
Ian
That's what I was wondering. It appears that replacing hydroquinone with ascorbate improves both grain and speed.Xtol was a new generation developer better fine grain than any PQ or MQ developer I'd used
I have no direct reference in literature, but Ron claimed, that there was nothing particularly attractive about ascorbates except their lower environmental impact. If you study patent literature from 80ies on, there are some patents with the aim to reduce/avoid HQ in developers.That's what I was wondering. It appears that replacing hydroquinone with ascorbate improves both grain and speed.
XTol is also made with Dimezone-S. The main difference between DD-X and XTol is, that the former emphasizes speed over grain and sharpness, whereas the latter tries to strike a balance with maybe a slight nod to sharpness. DD-X sums up decades of research into Phenidone/Dimezone-S based developers, whereas XTol embodies Kodak's ideal of a developer.BTW, according to my notes, the MSDS for DD-X says it contains hydroquinone and Dimezone S, not Phenidone. Maybe Dimezone S + hydroquinone can match PC?
Here is the msds of what appears to be an early one of the series, it contains metol, phenidone and dimezone-s:
https://www.fotoimpex.de/shop/images/products/media/56160_2_MSDS_DE.pdf
This suggests the use of both phenidone and dimezone together may give results that the inventor considered an improvement at that time.
That's what I was wondering. It appears that replacing hydroquinone with ascorbate improves both grain and speed.
BTW, according to my notes, the MSDS for DD-X says it contains hydroquinone and Dimezone S, not Phenidone. Maybe Dimezone S + hydroquinone can match PC?
Mark Overton
It has been stated here, that lower amounts of individual ingredients, even if a few of them essentially do the same, can help reduce the red tape to cut through when releasing a new product.This suggests the use of both phenidone and dimezone together may give results that the inventor considered an improvement at that time.
It has been stated here, that lower amounts of individual ingredients, even if a few of them essentially do the same, can help reduce the red tape to cut through when releasing a new product.
HQMS is much milder than hydroquinone and is used at a much larger quantity in E6 FD than what a typical hydroquinone quantity would be for a bw developer.Or there's something else going on involving some sort of attempt at making an in-situ synthesis - and there also seems to be a lot of HQMS-K in there. I really can't see it being a regulatory workaround.
I've read the patent, but not their paper. I'd probably need to go to a large library to find it, as I didn't see it online.Mark, have you read “The Genesis of XTOL” by Dickerson/Zawadzki (the Kodak principals on the project)? Granted there’s an inevitable marketing element and it isn’t a deep technical paper but still worth reading. I’d also suggest studying the XTOL-related patent (and the earlier infamous “Swedish patent”).
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