I'm new for photo, and also for CHDK.
I've downloaded the ALLBEST build firmware for my 860 and it works fine.
Among all the functions, I'm pretty interested in the ND Filter one.
In the setting of ND filter, there are three choices: (1) In (2) Out (3) Off.
It seems to me that (1) In is to activate the built-in ND filter in 860,
but I have no idea what (2) does.
Sorry if this is a stupid question.
Any help is appreciated.