Limit of ISO80 at long shutter speed of above 1 sec. on SX50Hs

Ketan Buch wrote:

On Amazon.com, I came across reviews which highlighted the limits placed on ISO @80 for night time long exposure above 1 sec. Can you please guide me as to how this would affect the images and what are the low light limits when one needs a long exposure ? How can this limitation be overcome ( without resorting to hack/CHKD). Pardon my ignorance but any advice would help in real world photography.