@CapeCodDan wrote:
@Waddizzle, thanks for the very thorough response! Yes I use high-speed continuous drive mode.
Swimming is a bit of a focusing challenge because you can’t continuously track the athlete moving toward you (as in basketball, soccer, football, etc) - because they are disappearing into the water, in fact there’s only brief moments when their heads are out of the water. I still used AI Servo figuring I could get two or three frames in each burst and keep them sharp. I chose single-point AF figuring I can always keep their faces centered under the focus point, with the system (hopefully) disregarding the splashing water surrounding. I frame a bit loosely to, again, be able to later crop for good composition even though the face is in the center of the frame.
I do have my C.Fn II-1 moved to “locked on: -1” to better stay focused on the subject. I also have C.Fn II-5 moved to “shooting speed priority”.
I’m a bit confused about your use of “AF Assist” since that term is used in the manual only in reference to speedlites. What I think you’re suggesting is to use zone AF instead of single-point AF, as that will better track the athlete as he/she moves?
I just realized that you are not the OP of this thread.
Any shooting situation presents its’ own focusing challenge. Just because it might seem difficult does not mean that it is impossible. If you are using only the center AF point, then I will have to agree with you and say focusing on a swimmer is impossible. I have already explained this, as have others.
When only a single AF point is enabled, the camera can only perform focus tracking of the nearest subject to the camera. Your sample photo is textbook proof of it. For action photography, you want the camera to track your subjects, and the only way the camera can track subjects is to enable multiple AF points.
I suggest that you download the AF Guides at the links that I posted earlier in this thread. They explain what AF Assist points are. There are various AF point selection modes. Zone AF is something different. AF assist points are the 4/8 AF points that surround your selected AF point. If you cycle through the AF point selection modes in the camera, the difference will become immediately apparent.
Using AF Assist points is akin to having an enlarged AF point. As you move the camera to track your subject, if your center AF point slips off of the subject, then one of the surrounding AF points can take the lead role in maintaining focus. In AF Assist point mode, the camera can “track” a subject, but it is still focus tracking, not true subject tracking. For subject tracking you need to enable one of the 3 AF zones, or all AF points in all of the zones at once..
The 6D2 does not have iTR tracking, which is actually most useful in video modes. Your camera can track colors, which is enabled by default. I hate to beat a dead horse, but I must. You must enable Zone AF in order to enable the camera to track colors of a subject. Using just a single AF point will result in the camera always focusing on the closest subjec to the camera, like splashing water.
As for the C.Fn.II settings, I would refer you to the AF Guides. The first 5 settings are what control how the camera will track moving subjects. Camera bodies llike the 7D2 give you the option to save the first 3 settings in a preset called an “AF Case”. Take a look at these. AF Case 2 is optimized to “continue to track subjects, ignoring possible obstacles.”
Download the manual to see an explanation of the settings are set the way they are. Keep setting 1 where you have it. Adjust settings 2 and 3 to “0”. The settings interact with one another. This combination should make the camera pause tracking for a beat. It tries to allow time for the obstacle between you and the subject to go away.
As for C.Fn.II settings 4 & 5, I suggest the exact opposite of wha though have selected. You have selected “shutter priority”, which means the camera will not wait for a focus lock before firing the shutter. I recommend setting both 4 and 5 to “focus priority”. Using “focus priority” might slow down the frame rate, at least in theory. Most lenses are fast enough that the difference is negligible. I would rather have a burst of 5-10 shots in focus, than 5-10 shots and only have 1-3 shots in focus, if any.
It is also possible to force the camera to stop AF on the fly by reprogramming the [AF ON] button to function as AF-OFF. This is especially useful when multiple obstacles may come between you and the subject for extended periods.
I know this may sound like a lot, and it is. This is why it takes practice and some experimenting with settings. What might work for one person may not work as well for you. The AF Case settings are defaults created by Canon engineers. Like I said above, I save action photography settings as a custom shooting mode. There are more than the three AF settings that I want to change for action photography compared to landscape photography.
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