If you've purchased a camera in the past few years, be it an SLR or a point-and-shoot, it's probably pretty smart. In most situations, it's going to make good decisions about where to focus, how much light to allow onto the sensor, how long to open the shutter, and whether to fire the flash (recall that flash isn't always a good thing). At other times, however, you may need to exert some control over your camera in order to capture what you want in a given scene.The good news is, many of those aforementioned cameras sold in the past few years also include a few buttons and switches that allow the kind of control you need to take more creative (or just better) photos. I'm not talking about general settings with names like "landscape", "portrait", and "sports"; rather, I'm referring to the same settings you would have found on your grandfather's camera 40 years ago.In my next few photography tips posts, I'll be discussing some of those settings. And since light is the most important element of photography, I'll begin with the settings most closely related to light: ISO, aperture, and shutter speed. I hope you find them worthwhile.