Warning on shutters
 

I have a Sony DVD-403 that is wrecked. The shutter leafs jammed shut. A common fault with these cameras to judge from the number of people who have ended up with wrecked DVD-403's I have found simply by Googling the model number. The problem seems to be dust, sand, or other debris, and in my case I lent it to my son, a teen who went to a beach party so...you can guess the rest.
I had a UV filter on it but he took it off for some unknown reason.
In looking at the SR-12 it also has similar shutter leafs, not three piece, but two piece as far as I could tell in the store. But very similar design.
I expect the Canons to be similar, it appears all these smaller cameras have these types of shutter.
Make sure you have the protective UV filter on always, if it happens that you end up with a jammed shutter use comperessed air/vacuum to try to clean out the dust. But don't use mechanical force they are incredibly fragile.
But the UV filter permanently in place is the way to go.