So I have just recently figured out how ISO affects photos. The higher the ISO (1600 is the highest my camera goes) the noisier (grainy) the picture. Since I have so far been a photographer that has been learning on-the-fly, I hadn't realized that ISO was what was causing all that noise in my photos. I had only realized that having the ISO up had allowed me to take photos at a lower aperture. Both of those of course were helping me get low light pictures in my house. I'm sure if I were to upgrade my camera (not an option since mine is only 1 year old) then I would get better noise reduction from a better sensor but now I'll just have to figure out how to get the photo I want in another way. Maybe I'll try some reflectors to get more natural light into the room....we'll have to see if I can figure that part out.