If you check the massive development chart you will see that it's *Generally* that higer ISO films require longer development film, but not necessarily.
For example, FP4+ in Rodinal 1+25 needs 9mins while HP5+ needs 6mins.
It dependent on both film and developer rather than a golden rule.
These recommendations are not made up out of thin air. Technicians at Agfa tested those film and developer combinations many, many times in order to publish them; and the times turned out to be what they were. This is true of all the manufacturers- after all they want their customers to make pleasing photos with their materials.
Of course with any new developer, you should run (at least one) exposure/development test to find the result you like.
I agree, it does seem a bit odd, but those times are at least a starting point.
I absolutely agree on every account. I was wondering what exactly could be the reason for such dev times. Which component is responsible? In what way? It is stated on the package that it contains aminophenol, and that certainly isn't a component I've encountered in any b/w developer I've used to date (I've gone through quite a few, I mix up my own, and my go-to formula for the last few years was 510-Pyro for pretty much everything). Could this be an effect of aminophenol? The way it interacts with another component? There certainly can be exceptions as with the Rodinal dev times specified above, but I think everyone will agree that the rule of the thumb is the higher the ISO, the longer it takes to develop the film. You leave it in the brine longer to push it, after all. It's just… logical. Clearly, some component of this developer reverses this logic and I want to know why.
The thing is, though, even though I'm interested in giving this archaeological finding a try (in my experience, photochemistry in powdered form lasts forever and then some), I definitely don't feel like sacrificing film or time on extensive tests. I am nonetheless curious about why longer development times are recommended for lower-ISO film (is it the shadows that take longer to develop or the highlights, and why, I'm always interested in why—which component does what). Surely some chemistry head out there knows the answer?
These times cannot be right, unless a different dilution is supposed to be used, which they may have forgotten to mention. It could happen! The exception is Fuji Neopan 1600, which did in fact develop very quickly. It was designed to do that.
Every film on this list except HP5+ has since been upgraded or discontinued, so it's pretty much impossible to test the times for consistency.
Would this be the same recipe as the Atomal 49 that Adox sells now?
ADOX ATOMAL 49 for 10 Films to mix 1000 ml - fotoimpex.com analogue photography
Film Developer ATOMAL 49 is an extra-fine grain, compensating developer which offers both excellent use of film speed and high contrast control. The powder developer ...www.fotoimpex.com
The MSDS says it has Hydroquinone and 'N,N-Diethyl-1,4-phenylendiammoniumsulfat' (I think you might anglicise that to N,N-Diethyl-1,4-phenylene diammoniumsulphate, but it still means not that much to me).
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