5dmk3 AI servo low light tests

jase1125 wrote in post #14787577
If the book states tracking does not work unless you are in all 61 point mode then yes he is absolutely wrong. For example if you are in expanded + 8 and start tracking a bird against a blue sky and the center af point gets off the bird, one of the neighboring assist points will acquire and continue to track. If the center point and the assist points get off the bird then focus will be lost. It will only use those nine points to track the subject. This is no different from the 7d and 1d4.

Ay, but theres the rub Jason.
Both the review and what Klostermann say that, Yes, it will track in zone of expansion, but not beyond those immediate areas.

So if you select zone all the way on the right side and don't keep that bird in flight lets say in that zone on the right, it could lose track of the initial target.
From what I read in Klostermann's book and what Martin Bailey said is that to have AI Servo continue to track completely across the frame, you need to have it in 61 point.

I think they are right.

KarlGB77 wrote in post #14787606
Ay, but theres the rub Jason.
Both the review and what Klostermann say that, Yes, it will track in zone of expansion, but not beyond those immediate areas.

So if you select zone all the way on the right side and don't keep that bird in flight lets say in that zone on the right, it could lose track of the initial target.
From what I read in Klostermann's book and what Martin Bailey said is that to have AI Servo continue to track completely across the frame, you need to have it in 61 point.

I think they are right.

Yes that is correct. I understood you were saying you need to be in all 61 points to track. That is incorrect. If that isn't what you were stating then I misunderstood. You need to be in all 61 point mode to use all 61 points for tracking. However, my experience with this body, the 7d and the 1d4 is all af point mode is the least reliable for consistent tracking as the camera is guessing the object you are tracking. Better to use one of the expanded modes.

KarlGB77 wrote in post #14786687
What I read Bobby is that in AI Servo using the different case settings, you need to use all 61 points so it can track.
Otherwise it won't track properly.

This specifically is an incorrect statement. Tracking, point switching and case selection are applicable in the zone and expanded modes.

Sorry for the confusion Jason.
I should have read your last completely.
A short while after I got my 5d3 in mid April, I went to Florida and was taking a lot of shots of birds in flight.
Not knowing what to do, I found the link that was posted about BIF and what to set the cases to.
I don't think he touched on what AF mode, i.e., spot with 4 or 8 or zone or whatever.
I'm not sure what I uswed but I am sure it WASN'T all 61 points and then select the starting point.
As BIF won't stay in the zone or expansion zone you started in, I didn't know what the answer was until I saw Bailey's review and found that Klostermann's book also said this.
Made me feel good about downloading the book while I was in FL in early May.

Here was Gary Luhm's BIF link. He did update it after I found it in early May but he did say this.

http://www.garyluhm.ne​t/bio/tips_0512.html

"AF point Auto Switching. This control only applies if you’re using one of the Point Expansion or Zone (multiple focus points) Area Selection Modes. It’s not available if you’re using Single Point (or Spot) AF. It sets how rapidly the AF point switches to a new AF point. Say you lock on a bird, and it banks and moves off as you’re firing. A +1 or +2 tells the camera to change focus points and stay on the bird. Best used with 61-point automatic selection AF, to give you the whole range to switch to.

Duhhh

So the bottom line is that if you want AI Servo to track using the entire range of AF points, the only way for THAT to happen is to be in 61 point AF.
Wouldn't it be the way to go if you want to track a moving subject and could select the starting point?

Thanks

Karl

Yes he is correct. I disagree about using all 61 points though. If one practices and can use one of the expanded options and keep it on target, the results will be better. All 61 will work, but the keeper rate is a bit lower in my experience. This is especially true when tracking against cluttered backgrounds. Many times it will acquire a new subject and lose what you are attempting to track. Of all the options, I find it least reliable. So much so that I usually disable that option altogether in the menu.

What do you like best Jason?
Expansion or Zone?
4 point expansion better than 8 point and zone?

Single + 4
Single + 8
Zone
All points AF (61)

Really I only ever use the top two unless I am tracking a very erratic small fast bird. Something like a bat or a dragonfly that is difficult for me to keep my point or cluster of points on. I use single point for very slow and steady subjects and I never use spot in servo.

Here is one using single + 4

IMAGE LINK: http://www.flickr.com/​photos/jason_nash/6902​467212/

I guess my original reason for adding to this thread is that having some shots not as sharp as others was that maybe the mode selected for AI Servo was what caused the issue.
i.e. losing track in a smaller 4 point mode and that being the reason.

Thanks

KarlGB77 wrote in post #14787798
I guess my original reason for adding to this thread is that having some shots not as sharp as others was that maybe the mode selected for AI Servo was what caused the issue.
i.e. losing track in a smaller 4 point mode and that being the reason.

Thanks

Certainly changing modes can be helpful. But if you are pretty good at keeping the point on the target, then I would look at the different cases and tweak those to see if your keeper rate increases.

Thanks Jason

One I took in FL when I was just learning.
100% crop of a 70-200 2.8 II

Honestly that isn't bad. Best I can tell af was on the bird and that is motion blur. Looks like you need to increase shutter speed (on my iPad so I cannot look at the exif), reduce the exposure and add some contrast and clarity and that would look much better. Do you shoot jpg or raw? What do you use to post process? I use Lightroom.

That was jpeg sooc.
I haven't gotten to the point of RAW and processing even though I have LR3 and PS CS 5.5 Extended.
Never even downloaded PS yet.

The pic was 5d3, w/ 70-200 2.8 IS II, taken at 200 mm at f4.5, SS 2000 at ISO 800

KarlGB77 wrote in post #14787711
So the bottom line is that if you want AI Servo to track using the entire range of AF points, the only way for THAT to happen is to be in 61 point AF.
Wouldn't it be the way to go if you want to track a moving subject and could select the starting point?

Thanks

Karl

That is correct but who wants to do that unless you tracking far away bird in a clear blue sky. Then all AF points make sense. That is why I used to have home button (left of * button on my 1dmk2) programmed as ring of fire.

In case here, I know my starting point and I make sure my starting point AF is on my target. Start tracking by using * button on back. And shoot as I track. The reason for going with 4 + selected starting point is to make it easier to track (put those points on the target where I want the AF to focus). If I used all points or didn't care camera will focus say on chest when I wanted to focus on eyes. That is the whole adavantage of having so many high precision points.