GeraldW wrote:
Bob,
I really think you'll want both a very long lens, and something much faster and more compact for low light and for places where you don't want to carry the superzoom. It would also give you a backup, just in case.
As to superzooms, the Canon models to look at would be the SX40HS or SX50HS because they have DIGIC 5 and can correct for chromatic aberration automatically, in-camera. Once you zoom a litle, both camera's lenses get quite slow, as both have lenses where the aperture changes quite rapidly as you zoom. By 140 mm, where the G15 is still f/2.8; the SZ's are already almost 2 stops slower. Fine for daylight; but forcing high ISO in dimmer light.
Both the Canon SZ's do fairly well at higher ISO; but neither one can hold a candle to the G15 in low light. I recently bought a G15 to replace a G11, and I'm really amazed at how much better the G15 is. It's also fairly light at 12.5 oz., and slim enough to fit into a shirt pocket.
As an alternative to the Canons, I can recommend the Panasonic FZ150 or FZ200. Both cover 25-600 mm, equivalent. The FZ150 at f/2.8-f/5.2 and only f/4 at 300 mm. The FZ200 is the same focal length and a constant f/2.8; and with a very high resolution EVF. Properly set up, image quality is excellent on both cameras. I own both.