are there any un/official firmware upgrades that can slow shutter speed? i want to buy the s5is, but am turned off by the fact that it can only go to 15 seconds. ideally i'd like an infinitely adjustable shutter speed, but i could live with 30-60 seconds.
alternatively, can anyone recommend a canon (or something else) that combines high image quality with a shutter speed of this type? i'm looking to spend around $500. thanks in advance

