According to reviews, the shutter lag on the Canon S3 IS and the Panasonic FZ7 are the same (0.5 second)
As far as the focus time you experienced.....are you sure that image stabilization was turned-on for both cameras? Did you try to focus on the exact same object?
According to the specifications, both cameras have manual focus.
I don't believe the focus is done by twisting a ring on the lens.
All digital cameras that use AA alkaline batteries will also use rechargeable NiMH AA batteries. So plan to spend about $20 to buy the NiMH batteries and a charger.
Buy NiMH batteries with a high mAh (Milli-amp hours) rating. Something near 2500 mAh.
NiMH batteries will last 3 to 4 times longer (on one charge) than alkaline batteries will last.
I looked at the Canon S3 IS and the Panasonic Lumix FZ7 today and felt that indoors the Canon had very little shutter lag, focused very quickly, but the Lumix was slow and didn't focus quickly. Is this common or was this just b/c they were demo cameras at a big store? I want something with a nice zoom, low shutter lag, quick focus (are there any that I can manually focus if I wanted to?). Also, I notice that some of the Canons take regular batteries. Is that a pain? Do they run out quickly?
Any advice would be appreciated.