Photos with S voice

[Sherlock HolmesNZ]

How can I set the S3 mini for taking photos on S voice. Camera will start with S voice but not take photos despite me saying shoot!!!! I get told to to click on Voice cmd but its not coming up in settings. I get told told find smart switch (or something like that in widgets but its not there.) Can somebody please give a nice simple plain English help to me please what to do