You can use any developer you like to establish ISO speeds, provided you say what it is. It might be interesting to see what developers Maco use for 25 and 80.
Cheers,
R.
Dear Roger,
in general yes.
But that is not the problem here with this particular film!
Agfa Aviphot Pan 80 is a real "Diva", a completely different film to any other normal BW films we know and use!
This film always has a very strong S-shape characteristic curve. Even in developers which normaly produce an excellent linear characteristic curve.
Aerial films have to be different:
If you photograph from high altitudes to the ground you have a flat light: Almost no shadows and no highlights. Therefore you need a film with very good separated midtones, and higher contrast in the midtones.
Therefore aerial films are designed to have a strong S-shape characterictic curve.
And Aviphot Pan 80 has an even much stronger S-shape curve than Aviphot Pan 200.
Just evaluate this film, make a Zone row and measure it with a densitometer. And use different developers.
Then you will immediately see!
Developer manufactuerer Moersch has given up on this film because it was impossible for him to get a more linear characteristic curve with his developers. for this reason you won't find this film in his datasheets.
Cheers, Jan