iPhone 4S/IOS6 - battery drain after the camera usage
I don't think its the GPS, do you have Photo stream turned on?  That will upload your pictures to iCloud.  One thing you can do is check usage to see what is doing on after you take pictures.  Is my iPhone 5S draining battery too fast (and is it due to process mediaServerD?) has good information in the OP about checking what is using your battery.