but i thought this programs ables and lets me adjust shutter to 64 sec like i wanted and apertue setting
Yes, that's what CHDK can do for you...
The IXUS / SDxxx cameras only have a ND filter, a kind of fake aperture;
you can setup the ND filter from the "Extra Photo Operations" menu with the item "ND filter state [Off/On/Auto]".
To do a 64s exposure, do the following:
- from the Canon menu, set up the camera to the longest exposure, normally 15 seconds
- set up the following from the "Extra Photo Operations" menu:
Override shutter speed [ 64]
Value factor [ 1]
Shutterspeed enum type [Factor]
Note: the Canon OSD don't show the 64s override, it will always show 15s - but your exposure will be 64s
(plus another 64s with "busy" on the display when the dark frame subtraction (for noise reduction) is enabled !