It’s true, discovery is as much due to accident as anything else.
I had been having some problems achieving the desired clarity of focus lately while taking pictures of birds. While I could get some really cool shots, such as this:
I simply was not happy with them. I believed that I should be able to focus well enough to see every feather. After all, other photographers “routinely” achieve that, so why shouldn’t I?
Don’t get me wrong, I have no idea how many shots the other photographers had to do to get that one super-sharp image. Plus most of them, that I follow anyway, focus on bird photography so they obviously refine their techniques for that. I, on the other hand, am a generalist with a preference for astrophotography and astrolandscape photography. Obviously, I’ve not put in the time they have pursuing the perfect bird image.
However, I have taken a lot of photos where I needed the image to be sharp.
So, why such a difficulty? How do I get around it?
A craftsman does not blame his tools. That’s a lesson I take very much to heart. Clearly, then, it is a matter of technique. Or of using the tool (camera) properly.
I use center spot focusing virtually all the time. That means that what I aim at is what I should be achieving my focus on. Logically, to me anyway, Depth of Field is perhaps an issue with the moving bird getting out of focus before I can take the shot. This is especially likely to be true as I also tend to use use AF-S (AutoFocus-Single). So, I focus on the bird then take the picture. There’s a lag there and if my DOF is shallow enough, that could be enough to blur even a slow moving bird slightly.
I’m aware of AF-C (AutoFocus-Continuous) and how it’s supposed to work. I’m aware, too, that many bird photographers utilize this mode almost exclusively. I assume they also use the Dynamic Area mode, if available. All this contributes to my problem most likely being a DOF and focus issue.
Last weekend, though, I discovered a trick. It may be well known to everyone else, but I achieved it by accident. Very simply, I forgot to remove my finger from a button while I pressed the shutter to take the picture. That button was the AF (AutoFocus).
I’ve long since moved my autofocus off the shutter button and onto the AF button on my Pentax K-10D. In a way, what I discovered is very much akin to the focus trap method I describe here. In this case, though, I am utilizing the autofocus instead of manually focusing for the focus trap.
What I did was aim my center focus point on the mallard I was trying to photograph. I pressed the AF button and got a nice, sharp focus. Then maintaining that focus point in the viewfinder, I took the photo. I did this a few times before I realized that I wasn’t releasing the AF button before taking the photos. I had been holding the AF button down all the way through the process: aim, focus, track, take picture. I was executing the focus trap method but letting the camera’s autofocus do the focusing for me. The end result was some wonderful photos of the mallards with the detail I had been seeking.
This will NOT work with a manual lens, of course, as there is no way to auto-focus it. I was pleasantly surprised at the results and hope to play with this technique with other active subjects. I do intend to look further into AF-C and Dynamic Area, as there are times when I won’t need to move the camera, but for the most part I’ll probably continue to use this new method. I’m not sure, and will experiment to find out, just how the AF-C would work when I lose track of the subject and have to re-acquire several times in a session. Holding the AF button down, while keeping the focus point on the target, and shooting may well work better for me in these situations. There will be some lens thrashing as it re-focuses, of course, if I lose track of my subject then regain it. That may not be a good thing with, for example, quick flitting birds in mid-air, but for those instances where I can easily track the target such as these mallards were, it should be an acceptable method.