Another make or break it component to any action shot is a
getting a good focus. Digital cameras focus best on areas with straight
lines and high contrast, not exactly the prime feature of whitewater.
Big water can be exceptionally tough.
This is an area of photography where Canon has been
far ahead of Nikon until the D700 and D3 which have made considerable
steps forward and past their counterparts. Being a Nikon shooter all my
comments will be based towards these cameras. The more expensive the
camera, the better and more confusing the AF system gets. I'll try to
keep it relatively simple here. As a side note I have used some third
party lenses, but have found that in general they miss focus more
often. In some cases like the Sigma 18-200, there is an incredible rate
of back focusing.
Nikon D50, Sigma 18-200 @ 116mm. 1/1000 F6.3 ISO 800. Note how
the rock and water in the background are in focus while the paddler is
blurry.
But it's just not third-party lenses. Nikon D200, Nikkor 18-200 @ 95mm.
1/800 F8 ISO 200.
Shooting with longer lenses can be tough. On many cameras
the center sensor often only truly reliable one, which is a shame since
we rarely, if ever, want the paddler in the center of he shot. One of
my favorite tricks is to focus on an object (rock or tree) that is the
same distance away as the paddler will be, then recompose my shot on
the rapid. It's easiest to do this without the shutter release
button triggering the auto focus too. This works on Nikons all
the way down to the D50, and I assume it would on Canons too. First
turn your auto-focus mode to Auto Focus Continuous aka AF-C. If it's a
lower end camera then through the menu system turn your AE-L/AF-L
button to "AF-ON". This disables the button as Auto Exposure Lock but
removes focusing from the shutter release. Now when you want to focus
you use the AE-L/AF-L button instead of the shutter release.
Higher end cameras have a dedicated "AF-ON" button.
Through the menu system you have to turn off the shutter release from
activating AF. Now the shutter release is just that, and the AF-ON
button us used when you want the camera to focus. On both make sure
you're set to continuous AF because it is more accurate, and once the
AF-ON button is released, your focus is set. AF-C also ties in nicely
to the next piece of AF advice.
Shot using my "longer lens" method. Nikon D200, Nikkor 50mm 1.8 @
1/1000 F3.2 ISO 100.
This method often doesn't work with big water, because there is
nothing near where the paddler will be. In this circumstance I'll
drastically change methods. Keeping the camera in AF-C mode, I choose a
side sensor (where I want the paddler to be in my shot) and keep that
sensor over the paddler as they come through the whole rapid, and
release the shuttler when they are in the desired location. A key
feature to pay attention to on high end cameras is focus tracking with
lock-on. This is just the delay (on or off and how long) the camera
takes before re-focusing when your subject vanishes, say behind a wave.
I keep this on normal or long for shooting big water. If you turn it
off, your camera is going to re-focus every time the paddler goes out
of view.
Focusing
with wide lenses: Missed up close focus. Nikon D200, Nikkor 20mm 2.8 @
1/1000 F3.5 ISO 100.
Focusing with wide lenses is easy if the object is over
five feet away, because if you have a relatively small aperture like F8
set, everything past five feet is in focus! Of course this is rarely
when a wide angle lens will look good. It's not about "getting it all
in" with a wide angle, it's about getting close to your subject; the
paddler. In the above shot I missed the focus trying to use the "longer
lens method" of focusing but estimated my distance poorly. Nail that
focus: Standing in the same shot with the same exact specs, but using a
different method of focusing.
When shooting up close I'll look through the view finder and format my
shot, noting where I expect the paddler to go. I'll then select that
focus area and make sure the camera is set to "Dynamic Area AF". Then
I'll do one of two things. If I know the exact composition I want, and
that it will be hard to get perfect again, I will compose the shot,
keep the AF-ON pressed down and wait for the paddler to come into the
frame. In this situation the above mentioned Focus Tracking
Lock On must be turned OFF.
If I am not as worried about the composition and just want to be
sure the paddler is in the right spot, I'll focus on them in the lead
in and keep the selected AF sensor over them (and on) while following
them through the drop, taking a shot (or sequence) when they are close
to where I want them. Once again this is best done with Focus Tracking
Lock On set to ON. While not easy to explain, these two methods should
help you achieve a better ratio of in focus shots.
Same situation but accurate focus achieved by following the paddler
through the drop with the AF sensor on them.