Just a short post real quick for those that know about their camera, but feel like there's more. In my opinion it's one of the most powerful buttons on your camera, hiding underneath the palm of your left hand. It's the "depth of field" preview button. Look where your lens attaches to the camera body and you'll see it. Have you ever wondered why your depth of field is so shallow when looking through your eyepiece, even after you have adjusted your aperture to add or subtract depth in your focusing range? Well this little button will take the guess work out and show you exactly what you're going to have in focus. It works by opening the aperture up to the setting you have it at. Simple! Try it out!