I'm just a beginner and trying to read up on this stuff. Tell me if I have this right: Aperture is the "amount of light" allowed in by the lens. I can set this to high f numbers (less light) or low f numbers (more light). This contributes to the exposure of the picture and also the depth of field, high f numbers giving a deeper depth of field, lower f numbers giving a shallower depth of field. ISO I'm a bit more confused on, but I believe when ISO is set higher the camera grabs more light from whereever it can to help expose the picture, risking more "noise" in the photo...graininess. So, tell me more about these two and how you use them. Many of my pictures are indoors and I want to get a natural feel to them, not whited out skin due to flash. So I would like to forgo using my flash. Even with a small aperture f number I don't have enough to expose (if I'm doing things right). I haven't messed with ISO yet but is that what I need to do is bump up the ISO if I don't want to use a flash indoors? Is there any other way to get a more natural looking photo indoors? Thanks!