The huge advantage of picking a system and staying with it is once you have learned how to use a Canon EOS or Nikon digital camera, other cameras in the line have many similarities. We shoot the more full-featured models available in each system, but have recently decided not to keep upgrading to the top-of-the-line cameras because the price difference between a Canon 1D Mark 4 and the new 7D is too much.  The 1D Mark 4 just isn't worth thousands more.  As of December, 2009, the cameras we are shooting include the Canon 5D Mark II, Canon 1D Mark III, Nikon D300, and the Nikon D3.  We learn all of the cameras as well as we possibly can.  When we buy a new model, we already know 80% of the instruction book, since there are so many similarities.  Our learning curve to mastering the new camera is actually quite low.

We do study the instruction book very carefully, looking for any new capabilities that can help us capture nice images easily and efficiently. I approach the instruction manual like I am studying for a college physics test. I pick a chapter and study it thoroughly which includes using a yellow highlighter to mark new important information. I even write short quiz questions down to see if I can remember the answers a few days later. I push all the buttons and go through the menus to make sure I can find my way around. Often with a new camera, I start with an easy chapter and try to master that. For example, prior to going to Kenya in 2010, I bought the Canon EOS 5D Mark II to go along with my Canon EOS 1D Mark III. I started with the introduction and then studied Chapter 1 which was about getting started. Then I jumped to the chapter that explained setting the AF, Metering, and Drive Modes.  These are all easy topics to me that I knew I could master quite quickly, helping me become more comfortable with my new camera.

Even a topic like autofocus, though, isn’t as easy as you might think. From teaching more than 200 people in week-long field workshops during 2009, it’s clear most students are not taking full advantage of their autofocus controls. Since I shoot Canon, I will discuss Canon controls, but Nikon can do the same things Canons do and sometimes more, though they use different terms. The Canon EOS 5D Mark II has three autofocusing modes called One-Shot AF, AI Focus AF, and AI Servo AF. To use these features, set the focus mode switch on the lens to AF. When the camera is set to the One-Shot AF mode, point the middle AF point in the viewfinder to the place where you want to achieve perfect focus, hold the shutter button down halfway, recompose, and press the shutter all the way to take the picture. It sounds like it is a fool proof way to accurately focus any subject that isn’t moving and it does work quite well if you are hand-holding the camera, something that we seldom do. This system doesn’t work well on a tripod because you don’t want to touch the camera or the tripod during the exposure to avoid causing the camera to vibrate which reduces image sharpness. Our workshop participants are generally greatly concerned about image quality, so they use a cable release or a self-timer to trip the camera and run into serious out-of-focus problems. Here’s what is happening. Let’s imagine we are photographing some frosted blackberry leaves during the autumn. While working on a tripod, our clients point the center AF point at a particular frosted leaf where they want to hit sharp focus and then recompose. Now the AF focus point is pointed between the leaves at a background several feet behind the frosted leaves. Pushing the shutter button to activate the self-timer or using a Canon Remote Switch RS-80N3 to take the image activates the autofocus, so the camera focuses on the background instead of the leaves, causing them to be severely out-of-focus. One way to solve this problem is to turn the AF switch on the lens off immediately prior to taking the image. Of course you’ll need to turn it back on each time you want to use autofocus again. With Nikon cameras, you’ll most likely have to turn the AF switch on the camera. There is a much better solution to the problem that I will offer later.

It’s usually best to sharply focus action by using continuous autofocus which is called AI Servo AF by Canon. By holding the middle autofocus point on the head or neck of a flying Canada Goose, the camera continuously tracks the goose, adjusting the focus for the changing distance to produce sharp images if the shutter speed is set fast enough.  (1/1000 second is a good choice)  This works quite well and makes sharply focused action images much easier to obtain than in past years with manual focus lenses.

Canon has introduced a third autofocus mode called AI Focus AF where the camera acts like the One-Shot AF mode, but if the subject begins to move, it switches over to AI Servo AF. This sounds great, but I haven’t tried to use it yet, so I just don’t know how well it works.  Besides, the enormous problems of using One-Shot AF on a tripod make it relatively useless anyway.

We've lead photo tours to Kenya once or twice a year since 1984.  It’s terrific for wildlife photography!  Most of the time One-Shot AF works great for a giraffe staring at you or a lion proudly perched on a termite mound. But, if that giraffe or lion suddenly begins to move, it’s necessary to switch over to AI Servo AF. To do this with the Canon 5D Mark II, you must press the AF button on the top of the camera, rotate the main control dial to select AI Servo AF, and tap the shutter button, so you can begin shooting again. It doesn’t take long to do this, but it does make it impossible to instantly go to action shooting. Once again, there is a better option for going from One-Shot AF to AI Servo AF and back again that most cameras can do, but the details are difficult to dig out of the instruction book.

At first it may seem cumbersome to activate autofocus on the back of the camera, but you get used to it in time. Using the back-button or AF-On button to initiate autofocus solves a huge problem for photographers who shoot on tripods. No longer does the cable release or pushing the shutter button to begin the self-timer cause the camera to refocus on the wrong spot. You can leave the AF switch on a Canon lens or Nikon camera body set to the on position all of the time. Another huge advantage for putting the autofocus on the back button is you can have instant One-Shot AF or AI Servo AF whenever you want it without the need to look at your camera to change the autofocus mode!  Sadly, this is an enormous advantage that far too many photograhers fail to understand.

Both of us use the following method with our Canon and Nikon bodies whenever photographing wildlife that could be still or suddenly move at any given moment. We assign the autofocus control to the button on the rear of the camera and set it for continuos autofocus which Canon calls AI Servo AF and Nikon call continuous-servo autofocus. We do not use One-Shot AF for wildlife or anything else for that matter because we don’t need to. Let me explain with an example. I was photographing a spotted hyena taking a bath in a large mud puddle. It was quietly looking at me as it sat half submerged in the puddle. I pointed the middle autofocus point at it’s face and pushed the AF-On button to make the lens focus right between the eyes.  Then I let up on the button to lock the focus, recomposed, and shot a few images by pressing the shutter button. Even though the camera was set on continuous autofocus (AI Servo AF in my case), the camera acted liked I had it set on One-Shot AF. As long as the distance from the camera to the hyenas face didn’t change, I didn’t have to refocus. If the hyena changed this distance, I repeated the autofocus procedure again. With practice, it only takes a second to do it. Eventually, another hyena galloped past the first, so I held the AF-On button down to initiate instant continuous autofocus, panned with the hyena, and made a decent image of it running. If I had to go to the buttons and dials to change from One-Shot AF to AI Servo AF, I could have never made the image. By setting the camera up to continuous autofocus on the AF-On button, I have a choice of One-Shot AF or continuous instantly. It’s a little known focusing method that has worked well for us for decades.  Even some film cameras offered back-button focusing in the eighties.

Back-button focusing is a terrific tool, but It doesn’t mean that we always have the camera set to continuous autofocus on the back-button control. There are times where we prefer the shutter button to initiate continuous autofocus. During our 2009 Kenya photo safari, I spent quite a bit of time with the folks in my safari vehicle who wanted to photograph flying flamingos at Lake Nakuru. One afternoon I led this group to a point of land that sticks out into Lake Nakuru where it’s likely that many flamingos will fly by the point closely, so we could fill the frame. Since we were only doing action shots and knew we would not need One-Shot AF, I reset custom function #1 in group #4 to the default choice, so the shutter button initiates continuous autofocus. Using the AF-On button does require two fingers, one to hold the button in, and the other to trip the shutter, so it is a bit easier if only one finger is needed to initiate autofocusing and trip the shutter. We always proceed this way if we know we are definitely photographing only action.

During fall color we normally photograph subjects that aren’t likely to move such as mushrooms, colorful leaves on the trees, frost, and gorgeous landscapes. In this case, we set the camera autofocus control to the AF-On button, but leave it on continuous autofocus. We also set our camera to mirror lock-up because the movement of the mirror just prior to the exposure can jar the camera a tiny bit causing a slight loss of sharpness, especially at shutter speeds in the 1/8 to 1/30 second range. With all of our cameras, we set the drive to a two-second delay. When I press the shutter button, the mirror moves up out of the way immediately, the camera counts off two seconds, and then takes the image. The two second delay allows any vibration produced by the movement of the mirror to dissipate before the actual image is taken.

By the way, we use the middle focus point nearly all of the time, even though most cameras permit selecting a number of focusing points. Not all focusing points are equal in terms of accuracy. Unless the lens is a fast f/2.8 lens, most focusing points are only horizontal line sensitive while the middle sensor is both vertical and horizontal line sensitive. Vertical line detection is more sensitive than horizontal line detection, so the center focusing point Is the most accurate one to use.