Drybags: Assistive or Asinine?

Heading to the islands in a few days and am considering buying a little dry bag for my Sony T1 to possibly use for underwater photos. Just curious how well (or not) they work for that function (trying to find a cheap alternative to a housing).

Not expecting professional quality of course, basically just wanting the photos to be in mostly in focus (concerned about it focusing on the bag, however I've read that rubber bands to keep the bag close to the lens should help). Also wondering if the colouring comes out wacky (washed out or super green) - anything that photoshop can't fix?

Thanks in advance for the advise guys!

I just bought a couple of Aquapac's SLR dry bags for very wet topside shots on my next trip.

I tested a bag in the pool and it seems fine for very shallow work as well as wet topside stuff (waves crashing over an inflatable etc).

I wouldn't take it lower than a few metres though (although it says safe to 10 m I think). The quality should be OKish, although besides the glass disk which keeps the bag lens tube 'open' you are shooting through a clear plastic screen. OK when the bag is new, but susceptible to scratches I'd think.

Also keep a small sachet of silica gel in the bag ....

one other thing - auto focus may have an issue if the bag obscures the infra red 'eye'. I'll be fixing my Sony A1 manually on infinity for much of the work I'm planning.

Not sure about the D50, although the other issue with SLRs is that the Aquapac bag won't take a long lens.

Good luck!

thanks!