So I picked up a great ebook by James Brandon and it was great! In there he talked about a number very useful techniques that will help improve the sharpness of your photos before they hit photoshop! This is something that we all need to take a bit of time and study rather than relying on the myriad of techniques to compensate for what should have been taken care before hitting the shutter release.
One of the most surprising ideas was the use of the AF-on button for focusing. I won’t go into too much detail so that I don’t take anything away from James, but I want to share my discoveries from this past weekend. This little trick could solve a great deal of problems, or just piss you off if you forget that you turned it on.
What you basically do is move the focus lock to the af-on button and away from the shutter release. Why? Have you ever focused on a subject only to hit the shutter and find that the lighting fast lens you bought refocused “lightning-fast” on the ground behind your subject? Yup, that is why. I know everyone will go on and on about pressing the button half-way and how it is more convenient, but trust me this helps.
For me it works well in many aspects of my photography. For HDR, at times (if you are not paying attention), the camera can refocus and you get an annoying blurred image with the stack of bracketed shots. Also if you are shooting with a wide aperture like f/2.8 or larger then you will know the challenges when it comes to focus and where you want to draw that attention to.
I am still getting used to having the focus button somewhere else but I am liking the focus lock because I can focus on a certain spot, recompose and know that when I press the shutter release that the camera is not going to change anything. For me that is the what I like it. My wife likes it too because I swear less when I am composing shots.
Of course, you can just switch to manual focus and not have to worry about any of this, but I still find this method better. You just have to take a peek into your camera’s custom settings and change it. If you don’t like it you can just change it back.
One of the main advantages to this method is that when you shoot HDR or time lapse, where you are taking a series of shots, you want to lock out the focus to make sure everything stays the same. Normally, I just switch the lens to manual focus and that’s that, but on my wide-angle tokina the switch is the entire focusing ring and thus, moves a bit when you switch it to manual.
With the back-button focusing, you just hit the button right by your thumb and boom! everything is in focus and nicely locked up. You don’t have to worry about the camera refocusing the next time press the shutter release.
Another great feature about using this function is the fact in low light situations where my 30D sometimes fights to find a spot to focus on, you have the freedom to move the camera around find a focus point, lock the focus and position/compose the frame.
All in all this is a handy little feature to use when you want to get the sharpest shots that you can. As I said, it may get a little annoying at first but after a while it becomes second nature.