I'm having a very strange issue with my HX 80. I'm trying to shoot Shutter priority at 100th, ISO auto peaked at 800. I'm looking at a dark area in the landscape. The aperture will only go down to f5, not down to the 1.8 or 2 that I would need. When I switch to manual mode, the lowest the aperture will go is f5. I think I am being held back by some other incorrect setting I am not aware of. I have done this many times in the past without a problem. Appreciate your help.