Grainy pictures at night
Low light without a flash will always cause grainy pictures unless you have a very high end camera that can shoot at very high ISO speeds like 6400 and up.
Try changing the camera from the green camera 'auto' setting to "P" and then press the Menu button (I think it's Menu) and look for the different mode settings. There should be one for Night or Night Portrait or similar, I can't recall Sony terms and I don't have one here to check sorry.
Your other option is to use the flash, try it with Red Eye turned on if possible.
Hope this helps.
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