That sounds like a perfectly normal result.
You’ll only get a sensitivity much higher than 64 ASA if the film is only a few weeks old.
I refer to my comments in the other threads regarding ADOX, where people asked why we don’t double-check every batch with the Densi.
Most other 100-speed films are similar. However, the varying shelf stability can sometimes cause confusion. Every film has roughly its nominal sensitivity on the day it is processed, and over 2–3 years it then drops to two-thirds of that, until the base fog sets in as well; by 3–6 years, it has reached the end of its ‘I’ll just start snapping away without testing’ usability. That’s why the expiry dates are printed on them :)
You might get a bit more out of it if you don’t perform dilution but use the stock solution instead. Given its very fine grain and soft rendering, the ATM 49 already extracts the maximum speed.
You’ll only get more if you accept a larger grain size and a hardener.
It’s also important how old the chemicals were and the quality of the raw materials. The buffer solution isn’t very stable in storage—that’s why we have the ATM 49 manufactured in exclusive batches every year and store it under special conditions.
If the developer no longer compensates sufficiently, your method (e.g. if you calibrate to beta 0.55) will result in lower speed.
Best regards,
Mirko
Hello,
What about the development times if I set a lower speed for older films? Do I need to shorten the times, or do I develop as I would at the nominal speed?
Wilfried
