Hello & welcome, turbines !
To set an item on the menu in the edit mode the manual says to use the "erase" or half press "shoot". I am not sure what those are on the S3.
Try the FUNC button - the one with the blue trash can symbol...
I would also like to be able to set a preset fixed Hyper Focal distance and Focal length as an option. Is that also possible with CHDK?
You could have a look to the
SD Override feature & the shortcuts, it could be done also with a small script...
