June 12, 2013
Black Bears In Trees and a Great Gray Owl in Yellowstone National Park, Wyoming, and Back Button Focus

Two Days Ago

It was the day of the bears in Yellowstone National Park two days ago because I saw 13 bears, including a different grizzly sow with three spring cubs. I only photographed three bears, but they were all great subjects. The best were the black bear sow with a spring cub because they were fairly close to the road and put on a great show for about five hours. Unfortunately, the environment was messy which limited shooting opportunities, and the bright sun between clouds in the middle of the day made it a really frustrating experience because there was lots of great action as the cub kept going up and down trees and playing with its mother and most of it wasn't photographable. Here's the extremely cute and active black bear spring cub climbing a tiny tree in diffuse light. That's just about perfect mammal light because there aren't any harsh shadows and there's great texture in the fur and the eyes can be quite visible. Here's the spring cub's mother climbing an aspen tree in bright sunlight. That's about as bad as it gets when photographing a dark-colored animal because there's so much contrast between the subject (black bear) and its surrounding (white aspen trunk). Fortunately, I was able to process the RAW file three times to help bring out detail from the shadows to the highlights, but it's still really contrasty. I like the image because it shows some good behavior. Black bears are great tree climbers, but they're usually obscured by lots of branches. It was amazing to see her climb the tree because she was so fast — think lumberjack tree-climbing competition.

Yesterday

We photographed the same black bear sow and spring cub again. They played almost out in the open one time, but the sow's lower body was blocked by the tree trunk where they had been seeking some privacy from the paparazzi. Really frustrating. The highlight of the day was photographing a great gray owl and chick on the nest. We were given a tip and had no problem finding the nest. It was the first time I've photographed this species, and it was great to have an eight-day-old chick too! The light was low and I had to use the 600 f4 II and 2x III to get enough reach, so I was quite surprised by the great image quality from the 1D X shot at ISO 1600 and only 1/125 sec. There was very little distracting noise on the owls, and I only performed some mild noise reduction on the out-of-focus areas. I'm totally loving my new setup!

Back Button Focus

Most cameras activate autofocus when the shutter is depressed half way. That's great as long as you can place a focus point on the subject when it's composed as you'd like, but not so good if you can't. I've occasionally run into problems where the autofocus points aren't close enough to the corner to compose an image exactly as I'd like, but lately I've been really constrained by using the 600 f4 II and 2x III because only the center focus point of the 1D X works with a lens/teleconverter with a maximum aperture of f8. This is true for all Canon 1-series bodies and the 5D III. Other Canon bodies can't autofocus at all when the lens/teleconverter has a maximum aperture of f8.

Lots of nature photographers use back button focus, or rear focus, to overcome this problem. Instead of autofocus activating when the shutter is depressed half way, autofocus is activated by one of the buttons on the back of the body usually near where your thumb naturally rests. To take a picture of a stationary subject, or one that's mostly moving in the plane of focus, you place any active focus point on the subject, hit the rear button to activate autofocus, release the rear button to lock focus, compose the shot, then hit the shutter release. For a subject that's moving towards or away from the camera, and the camera's in AI-Servo (Canon) or AF-C (Nikon) mode, keep an active focus point on the subject and continue to hold the rear button down while activating the shutter.

Back button focus is also a great way to effectively instantly switch between AI-Servo (Canon) or AF-C (Nikon) and One-Shot (Canon) or AF-S (Nikon) and even manual focus modes if the camera/lens is set to AI-Servo (Canon) or AF-C (Nikon). By continuing to hold the back focus button, the focus will act like AI-Servo (Canon) or AF-C (Nikon) mode. By pressing and releasing the back focus button, the focus will act like an improved One-Shot (Canon) or AF-S (Nikon) mode. By ignoring the back focus button, it will act like manual focus.

I tried back button focus years ago and couldn't get the hang of it, so I returned to the traditional shutter button focus. Yesterday while photographing the great horned owl, I set up the 1D X for back button focus, and I think I'll stick with it this time because of the much greater flexibility when photographing stationary subjects, especially when only the center autofocus point is available. I actually programmed both the AF-ON and * buttons because the AF-ON button is a bit far from my natural thumb position and I had already programmed the * button to be inactive instead of exposure lock.