Probably trial-and-error (or use a potentiometer), especially since you probably don't know how much light is hitting the photodiode.
...You may not want to use a pot "permanently", but it could make the experimenting easier.
Probably trial-and-error (or use a potentiometer), especially since you probably don't know how much light is hitting the photodiode.
...You may not want to use a pot "permanently", but it could make the experimenting easier.