When you are composing a photograph you as the photographer have the ability to choose where your camera will focus. If you are using a canon you will most likely have nine different points to choose from and three different focus types.
First let's address the focus types. The most common one to use is single shot. When using this mode you depress the shutter part way down your lens auto focus takes over and you press the shutter button all the way and presto a perfect photo:) The next option is AI focus. Much like single shot depress the shutter part way and the camera will auto focus on the point or points you have chosen. The nice thing with this mode is if you continue to depress the shutter part way and you subject moves you auto focus continues to track that subject and stay focused till you snap the shot. Last is AI Servo. In this mode your auto focus will track the subject constantly and even "learn" what it should be focusing on. Now this technology sounds amazing, and it is, until you start recomposing your shot and your camera tracks everything except the subject you want to shoot. Step in back button focus.
Through your camera menu settings you can disable the shutter button for focus and use one of the buttons on the back to focus with. Now you may ask yourself "why would I do that shutter focus is obviously the best way and that's why the camera company uses this default" right? Wrong. Camera companies use this feature because using a shutter button is normal practice and has been since cameras were invented, but remember the camera of our fathers and grandmothers did not have auto focus. Focus was gotten by turning a dial on the lens to bring the elements into alignment thereby achieving a crisp clean focus. Now with the flip of a switch and a press of a button a little red light appears in your view finder telling you the focus is perfect on your subject. So enough history, why use back button focus?
Look through your viewfinder at your subject, press your shutter part way down, look at the little red light in your viewfinder flash as your auto focus locks on to your subject, recompose, shoot. Now shot two. Look through your viewfinder at your subject, press your shutter part way down, look at the little red light. Get my point? This is very time consuming. Now change your camera to back button focus. Look through the viewfinder, press your back button, recompose and shoot. As long as your subject stays the same distance away from your lens you can recompose and shoot to your heart's content. This is the true beauty your shutter no longer has any use except what it should be for, activating the shutter, not focusing. If you choose to use your AI Servo mode you will find that again because it is independent of your shutter tracking your subject will be smoother and pressing your shutter button will be more fluid and controlled.
Anyway sorry for the lack of recent blogs. I hope you go out and try this new style of using your camera and as always I look forward to hearing your comments and getting your emails. Till next time.