Developed for 45 min with APH 09

My son gave me some advice yesterday:

Develop a 13X18 Foma planfilm 100Iso for 45 min in APH 09 delutied 1:80....used a tank....
And with great succes.... Just agrigated 4 times in the start and let it stay for the rest of the time.....
Never had a so fine negative.....

Can anyone explain what is going on ????

It's a variation of 'stand development', where you let the negative pretty much just it 'stand' there with little agitation.

Some people call stand development with increased agitation 'accelerated stand development'. It can me used for push processing too to get higher EI/ISO.

I think it's considered a compensating development technique, but I can't really explain that. Hopefully someone else will come along & add to this or correct me.

Obviously your son knew what was going on!

Murray