What about aperture and ISO?
Id like to know this for Aperture. I cant see an entry for Av (Aperture) anywhere in chdk on the camera. I can change shutter speed and ISO.
This cam (like most ixus/elph models) does not have an iris diaphragm, but uses a Neutral Density filter,
which you can control in CHDK menu Extra Photo Operations -> ND filter state, options are:
[off] -> auto, set by Canon
[in] -> CHDK makes sure the filter is used
[out] -> CHDK makes sure the filter is NOT used
Note that your effective Av will also be influenced by your zoom position.
HTH,
wim