I've had pretty much all my pics rejected for noise, so I need some advice on reducing it. I use a cheap Sony Cybershot DSC-W80 7.1MP P&S(totally inadequate, but I still try) and always shoot at ISO 100(no manual settings, which kinda sucks).
This is probably the least grainy aviation pic I've taken to date(though there is slight vignetting):
Unfortunately most of the shots turn out to be fairly noisy and turn out to be more along the lines of this. Usually it's the sky that's most noticeably noisy
Anyone have any useful advice for reducing grain? Unfortunately I can't afford a DSLR right now, though I hope to get a D40 someday.