topic Re: AI Servo - Number of Focus Points in General Discussion

AI Servo - Number of Focus Points

Waddizzle — Sun, 15 May 2016 13:31:00 GMT

I am basically a still photographer. Apparently, my renewed interest in photography has created a reputation of me being some sort of photography guru. HA-HA So, folks with smartphone cameras have begun asking me to come and take pictures for them of this, that, or some other event. No weddings, just Little League games, and the like.

Shooting stills means using One-Shot focusing mode, which may not be best for moving subjects. So, I've been exploring and experimenting with AI Servo mode. Which, brings me to a question that I cannot answer.

Does it matter if I am using just the center focus point, or should I need to turn of manual point selection altogether?

So far, my experiments have been inconclusive. My shots are in focus, but I am attributing that to pre-focusing. I get much better results by pre-focusing, than when I don't. Keeper rate is pretty much the same with manaul AF point selection, no matter if I use One-Shot or AI Servo modes.

I pre-focus on a player, or where I expect a player will be: i.e.; focusing on the base ahead of the base runner. I can get good shots, like the above play at third base. [the shot has been cropped to remove faces and team information]

But, forget about refocusing on an outfielder chasing down a ball. The kid is running, so One Shot doesn't work out very well, but neither has AI Servo with only the center point, manually selected. Turing on all of the AF points, 9 in a 6D, results in the camera frequently focusing where it wants, not where I want it to.

I guess I am saying that it seems that I have not been able to have the camera actuallly track a moving subject. So, do I need to turn on all AF points, in order to make it track in AI Servo, or not? For me, I am having bad luck relying on automatic AF point selection to pick out the running kid in the outfield, instead of a background tree, or something.

Re: AI Servo - Number of Focus Points

ebiggs1 — Sun, 15 May 2016 14:02:27 GMT

You know my answer. Use just the center point. All the pros I know, use just the center or they pre-focus. Remember I have 65 I could use but I use just the center 98% of the time. If you are always following the action, you will never be a great sports photographer. Guru or not ! IMHO, of course as always.

My 1D Mk IV can not focus as fast as it can shoot. So, it is a moot point there. Your 6D even though it is a slower camera probably can not focus as fast as it can shoot either. That is if you are using hi-speed shooting which I assume you are. Singles, use center point.

Re: AI Servo - Number of Focus Points

diverhank — Sun, 15 May 2016 14:18:34 GMT

The difference between one shot and AI Servo is that the camera continues to track the target once you achieve focus and keep the focus button/shutter depressed. For a single focus point, as you observed, you must keep that point on the moving target all the time then the camera will focus on it automatically.

In practice, with Canon 9 point cameras, I find that AI Servo effectiveness is very limited. With more points, you can select center AF point with either 9 assists (5D3) or 14 assist points (7D2) and AI Servo really sings for the occasion that I can't keep the center point on target. I'm primarily a BIF shooter and I use AI Servo 99% of the time.

Re: AI Servo - Number of Focus Points

Waddizzle — Sun, 15 May 2016 15:18:35 GMT

"You know my answer. Use just the center point. All the pros I know, use just the center or they pre-focus."

Yeah, manually select the just the center point, CP, I kmow. But, is that using One-Shot or AI Servo with moving subjects? Like I said, I can to really well pre-focusing, and anticipating movement.

My problem is quickly switching from one subject to the next subject, like during an outfiled catch, and throw to the plate. I get best results pre-focusing the manaul CP selection in One Shot mode, but that means not moving the camera. I get the best results when I am moving the camera with automatic AF point selection using AI Servo mode.

Is there no happy medium? Manual AF points and AI Servo has a lower keeper rate. Automatic AF points and One-Shot has a lower keeper rate, too. I have found I have to choose between a relatively staionary camera mode, or a moving and tracking camera mode. The latter mode means switching subjects is very finicky. The former mode is relatively easy to switch, with BBF, but I have to pick my new pre-focus point, which is a hit or miss proposition.

Re: AI Servo - Number of Focus Points

Waddizzle — Sun, 15 May 2016 15:23:53 GMT

"In practice, with Canon 9 point cameras, I find that AI Servo effectiveness is very limited. With more points, you can select center AF point with either 9 assists (5D3) or 14 assist points (7D2) and AI Servo really sings for the occasion that I can't keep the center point on target. I'm primarily a BIF shooter and I use AI Servo 99% of the time."

Maybe, AF assist points is the happy medium that I have been looking for. Keeping just the center point on subject is pretty tricky, which is made even more difficult with a big lens...tripod or monopod required, at least for me.

My thing has long been photographing still subjects, not subjects in motion. This is a whole new world of photography for me.

Re: AI Servo - Number of Focus Points

ebiggs1 — Sun, 15 May 2016 15:42:22 GMT

There is little need to go over all the stuff I already said. You know what I use. Just the center point.

But the correct answer is, use what works.

All the pros I know use just the center point. They all use three or more cameras. I usually use two. My 1d4 with a 300mm f2.8 lens. It is always on f2.8. I never change that. Wide open all the time. My second camera is the 1ds3 with a 70-200 f2.8. It is always on f2.8, too. I keep my 24-70mm f2.8 bu my side at all times, too.

There are some more important things to consider. If you don't know BB, I mean really know it, you will never, ever, nada, not be a good photographer. Anticipation is why. You need to know what is coming. Pre focus we already discussed.

My set up is the 1ds3 and 70-200 on a tripod fixed on first base. Remote trigger. My 1d4 with 300mm on a monopod for home plate. I like to be on the first base side line. Which is the last of the mandatory thing, location. Where you are is the most important part. That goes hand in hand with knowing the game.

Are you using HS drive? I doubt your camera can focus on anything while it is firing at HS. My 1d4 at 10 fps doesn't leave enough time between shots for the lens to focus. If you think it does ..............................?

Re: AI Servo - Number of Focus Points

RobertTheFat — Sun, 15 May 2016 16:39:02 GMT

@ebiggs1 wrote:
You know my answer. Use just the center point. All the pros I know, use just the center or they pre-focus. Remember I have 65 I could use but I use just the center 98% of the time. If you are always following the action, you will never be a great sports photographer. Guru or not ! IMHO, of course as always.

My 1D Mk IV can not focus as fast as it can shoot. So, it is a moot point there. Your 6D even though it is a slower camera probably can not focus as fast as it can shoot either. That is if you are using hi-speed shooting which I assume you are. Singles, use center point.

Ernie, I've never understood your preoccupation with using only the center point. It's a fairly well accepted principle of composition that the main subject shouldn't always be centered in the frame. So you're left with either re-positioning the camera after focusing or focusing away from the subject. Why either of those options is A Good Thing requires further explanaton which I don't think you've ever provided.

Re: AI Servo - Number of Focus Points

Waddizzle — Sun, 15 May 2016 16:45:05 GMT

All the pros I know use just the center point. They all use three or more cameras. I usually use two..

-------------------------------

Don't worry about my lack of sports knowledge. I know Bo.. I figured out using the center point after a month.

Using multiple cameras, now that is a thought, which I had not considered. I like the idea of one camera on a tripod remaining focused at one base, with a remote trigger. I've never felt comfortable with my monopod. Maybe, I'm too tall for it.

I've been long thinking about picking up an intervalometer for time lapse shots, which can also function as a remote trigger. What has held me up has been the fact that my T5 and 6D have different remote switch connectors. I'd need one for each camera, unless I can find an adapter of some sort. I just recently decided to spring for the 6D remote, though.

Back to baseball, and shooting moving subjects, I have two different shooting scenarios, still and moving subjects, for which I get the best results with two entirely different camera settings. Using center focus is more adaptable to double duty than Automatic AF point selection with AI Servo.

Re: AI Servo - Number of Focus Points

ebiggs1 — Sun, 15 May 2016 16:58:30 GMT

"Maybe, I'm too tall for it."

I am 6'3" and 230 lbs.

"Using multiple cameras, now that is a thought, which I had not considered."

That is what I meant by "knowing the sport". Just knowing the rules is not knowing the sport for photography point of view.

Pre-focus on a point because you "know" what is about to happen.

It really isn't just BB. It is anything you ever shoot. You must "know" it. Otherwise, you will never be good or successful. No matter if it is a wedding or a musical, etc, whatever.. I always attend rehearsals, for instance, to learn what is going to or likely happen next.

Re: AI Servo - Number of Focus Points

Waddizzle — Sun, 15 May 2016 17:19:28 GMT

"Maybe, I'm too tall for it."

I am 6'3" and 230 lbs.

"Using multiple cameras, now that is a thought, which I had not considered."

That is what I meant by "knowing the sport". Just knowing the rules is not knowing the sport for photography point of view.

------------------------------------------------------------------------------------------------

I don't see a correlation between using multiple cameras, and "knowing the sport". Seems to me that is more about knowing your gear, more than anything. You cannot be in two places at once. You cannot switch quickly enough between different shooting scenarios with one camera, either.

I captured the shot at third base because I knew the kid at the plate was a good hitter, and would likely hit the ball to the outfield, which he did. Runner tagged up, and I captured the shot of throw into third base. Does that meet your standard for "knowing the sport"?

BTW, I am 6'8" and 220 lbs. Most tripods are too short for me. Probably why I lean towards bigger video tripods.

Almost every monopod made is too short for me. But, my biggest problem with monopods has been what type of head to use with them. Ball heads on a monopod don't work for me. Camera rolls from horizontal too easily.

I've found that tilt heads, or pan/tilt heads work the best, which does not mean that they work out well. Forget about pointing up towards a bird in flgiht, too short. I have found a Benro monopod that is "my size", though.

Re: AI Servo - Number of Focus Points

jrhoffman75 — Sun, 15 May 2016 19:55:44 GMT

This is an excerpt from a 1D Mark IV guide by canon, but the concept is the same for all cameras. AI Servo is doing math, and you need to give it a little time to compute.

Re: AI Servo - Number of Focus Points

Waddizzle — Sun, 15 May 2016 22:39:54 GMT

Thanks, John, for that info. Allowing time for the AI SServo to focus on a subject, is why I have started BBF, instead of trying to hold the button halfway while moving the camera. That just doesn't flow for me, yet.

The issue I have been pondering and experimenting with is how many AF points I should have active during AI Servo. I seem to get better results with just the center point, out of 9. I can select my subject better with just one point. But, it is harder to track a moving subject with just the one point, and I seem to lose tracking altogether.....assuming that I ever got it tracking.

I am pretty sure that I only seem to get better "tracking" with the center point, because i can initially pick out the subject better with just one active AF point. But, it is more difficult to move the camera well enough for it to sufficiently track a subject with one active AF point, which is also dependent upon how much the subject fills the viewfinder. There are definite too big and too small limits.

[SIGH] You cannot win for losing. I hope a 6D mark II has AF assist points, and a more sensible DOF button.

Re: AI Servo - Number of Focus Points

ebiggs1 — Mon, 16 May 2016 11:33:36 GMT

"I hope a 6D mark II ..."

"BTW, I am 6'8" and 220 lbs."

If anybody I have ever met should get a 1 series it is you. Your size is a match. I can't imagine you are comfortable with a Rebel. Or even a xD series for that matter. My size and the total lack of being impressed by a 6D was just another plus sign for a 1 series. If you can't drop the coin on a 1Dx look for a clean 1D Mk IV. Once you go 1 series, you will never go back. That's a fact, Jack! IMHO, of course, as always.

Re: AI Servo - Number of Focus Points

ebiggs1 — Mon, 16 May 2016 00:25:35 GMT

"I don't see a correlation between using multiple cameras, and "knowing the sport". Seems to me that is more about knowing your gear, more than anything."

OK you must do as you must do.

But it is 100% knowing the sport. All the rest falls in place when you know what is going on. All the time! I am sure this is just your lack of experience but I am glad you are trying and hopefully learning, You will find after a few dozen games how much better or different you shoot and approach it. You don't learn this stuff on the inter web. You learn by doing.

"You cannot be in two places at once."

Maybe not physically but, yes, you can be in two places at one time? One eye is looking through the view finder and the other is watching what else is going on. I even use the LCD as a mirror to look behind me while I am shooting.

"You cannot switch quickly enough between different shooting scenarios ..."

You better learn this. One way is to use two or three cameras. I know you have not been in the pit because they are not, well lets say gentle with the gear.

Re: AI Servo - Number of Focus Points

jrhoffman75 — Mon, 16 May 2016 01:18:41 GMT

I use center point with the surrounding points.

Re: AI Servo - Number of Focus Points

Waddizzle — Mon, 16 May 2016 07:03:13 GMT

"You better learn this. One way is to use two or three cameras. I know you have not been in the pit because they are not, well lets say gentle with the gear."

Me? In the pit? HA-HA. No, I've used to be the guy who the ones in the pit have been photographing. When I told you, "I know Bo.": I meant that literally, at least in the past tense. You're very good at manufacturing false premises.

Re: AI Servo - Number of Focus Points

Waddizzle — Mon, 16 May 2016 07:06:19 GMT

Thanks, John, for the brainstorms. I have never paid attention to the tracking adjustments before.

Re: AI Servo - Number of Focus Points

ebiggs1 — Mon, 16 May 2016 11:29:24 GMT

"You're very good at manufacturing false premises."

And you are very good at hiding your persona. Who or what you are? Who cares? The inter web allows a lot of anonymity. So anyone can be any thing they can dream up. I put it all right out there for all to see. Got nothing to hide.

BTW, I knew Bo when he was at Auburn. You may know he played for the Royals.

Re: AI Servo - Number of Focus Points

RobertTheFat — Mon, 16 May 2016 11:54:24 GMT

@ebiggs1 wrote:
"You're very good at manufacturing false premises."

And you are very good at hiding your persona. Who or what you are? Who cares? The inter web allows a lot of anonymity. So anyone can be any thing they can dream up. I put it all right out there for all to see. Got nothing to hide.

BTW, I knew Bo when he was at Auburn. You may know he played for the Royals.

Who is Bo, and how did he make his way into this conversation? I thought I'd been paying attention, but maybe not.

Re: AI Servo - Number of Focus Points

ebiggs1 — Mon, 16 May 2016 12:21:37 GMT

Vincent Edward "Bo" Jackson. He played running back for Auburn while my father was at Alabama teaching. Alabama vs Auburn is a state stopping event in Alabama. Nothing is more important than that game.

He later came to the KC Royals as an outfielder. He was a once in a life time athlete. He played football for the Raiders, too. He got hurt which ended a Hall of Fame career for sure.

Way, way back before the NFL and American League got to be big business a guy could bring camera gear to the game. No big deal. Of course now even the photographers pit is a big business deal. You pay to be there, if you even can. I used to shoot lots of photos at games. Players even had summer or winter jobs. Regular Joes! Regular jobs! Frank White, Hall of Fame 2nd base, for instance worked at Hallmark while I was there. Cool guy.