Unless there’s motion, don’t use AI SERVO.

[PajamaGuy]

I’m sure the experts here already know this, so this is for those of us who aren’t experts.

Little League 10U when I’m sitting behind 2nd base with my 7D2 and 70-200 2.8 mounted on a monopod and shooting the batter at 10 fps I often get several frames (from the 2nd frame on) that are just slightly out of focus. Some are tack sharp, some are just a tad off.

I’ll skip right past explaining all the troubleshooting steps I took, and go right to the 1st phone call to Canon Tech Support. The guy really didn’t have a clue and told me to reset the camera to factory default settings – he even told me all DSLRs should be reset at least once each month.

I reset it, but no joy. Single shots were tack sharp. Action shots – following the runner – were tack sharp.

After setting up a tripod and a static target, and shooting a couple of hundred frames using various lenses – I called Canon again. This time I got Mike. I didn’t have 50 words out of my mouth when he said, “Take it off AI Servo.”

AI Servo expects movement - changes in the focus plane of the target - and when it doesn’t see them, it “hunts” just enough to soften the focus.

So I changed it to AI Focus and zipped 20 frames at my target. All of the were tack sharp. Thank-you Mike!

For single frames, any of the 3 settings work (but Single Shot is best). If the subject is moving when you start a continuous shot group, use AI Servo, but if you start with a subject that starts static, and then begins to move, use AI Focus. Problem solved.

[cicopo]

I found that too when I first tested my 7D2 but so far none of my other bodies are that fussy. Might be the improvements in the AF system the newer bodies use.

[TTMartin]

That advice goes back many years, but it is good to hear it again.

It also is a good reason to review the videos below, even if you have watched them a couple times before.

A Look at The Canon Autofocus System Part 1

A Look at The Canon Autofocus System Part 2

A Look at The Canon Autofocus System Part 3

[PajamaGuy]

Thanks - I'd viewed them in 2014 - but they're worth a revisit.  Actually, it was after watching Rudy that I pretty much locked the camera onto AI Servo.

So, it now begs the question, "Why not leave it on AI Focus all the time?" - I know I read or heard something about when AI Focus switches from One Shot to AI Servo it's "slower"....  I'm searching, but can't find it written as to what is "slower".  Is it the 1st frame after it switches to AI Servo? 

Does the AI Servo that AI Focus switches to, focus subsequent shots slower than if the camera was set to AI Servo?

When I sit on the foul line beyond 1st base and aim at the batter, AI Focus does a better job of holding focus on the batter than AI Servo did.  But as the batter runs toward 1st (directly at me) - some frames are very soft. 

I have to test a sequence using each, and also play with the tracking sensitivities, but I am just looking for the explanation of why use AI Servo instead of AI Focus.

Would I be better off to assign a button to execute the "switch between One Shot and AI Servo"? 

Thanks!

[TTMartin]

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@PajamaGuy wrote:

Thanks - I'd viewed them in 2014 - but they're worth a revisit.  Actually, it was after watching Rudy that I pretty much locked the camera onto AI Servo.

So, it now begs the question, "Why not leave it on AI Focus all the time?" - I know I read or heard something about when AI Focus switches from One Shot to AI Servo it's "slower"....  I'm searching, but can't find it written as to what is "slower".  Is it the 1st frame after it switches to AI Servo? 

Does the AI Servo that AI Focus switches to, focus subsequent shots slower than if the camera was set to AI Servo?

When I sit on the foul line beyond 1st base and aim at the batter, AI Focus does a better job of holding focus on the batter than AI Servo did.  But as the batter runs toward 1st (directly at me) - some frames are very soft. 

I have to test a sequence using each, and also play with the tracking sensitivities, but I am just looking for the explanation of why use AI Servo instead of AI Focus.

Would I be better off to assign a button to execute the "switch between One Shot and AI Servo"? 

Thanks!

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That is one of the scenarios where, BBF or in my opinion better yet reprogramming AF ON to AF OFF comes into play. After your initial focus on the batter with the camera in AIServo, simply suspend AF until the batter starts to move. With BBF you remove the AF start from the shutter and press and hold the AF ON button anytime you want to AF. With the AF OFF option you leave AF start on the shutter button, but, use the back button to stop AF anytime you don't want it. Like to prevent hunting on the batter, or when you want to manually focus, such as to photograph something going on the other side of the chainlink. 

You might also benefit from assigning either the AF ON button, or the DOF Preview button to temporarly switch from AIServo to OneShot.

[Waddizzle]

"You might also benefit from assigning either the AF ON button, or the DOF Preview button to temporarly switch from AIServo to OneShot." 

Whomever decided to put the DOF Preview button, on a 6D, on the front of the camera, out of reach, needs their head examined.

[ebiggs1]

I can tell you how I shoot baseball. Right or wrong, I still get asked by Moms and Dads to do it so I guess it is 'right'.

Switching from multi-point to single-point focusing.  Use the focus point at the centre of the frame.  It is faster and also lets you tell your camera exactly what you want to focus on, rather than letting it guess.  Matter of fact single focus point is best 90% of the time for any shooting.

My favorite lens ia a 300mm f2.8 and kept at f2.8. I never take it off max aperture.  Limit the close focus adjustment so the lens doesn't have so far to travel to focus.  Set the camera to M (manual).  ISO 1200 to 1600. SS at least 1/500. Adjust ISO to maintain this. Even 3200.  As stated max aperture, in my case f2.8.  I use Ai-Servo.  These can and will need some changing as required.

But I will add one step some people don't do and it works very well.  That is pre-focus on a point.  Wait for the player to get there!

Last point form me to anybody that shoots any kind of sports is, location, location and location.  That is the most important part of shooting baseball (or whatever sport).

This is how I do it, Good luck.

[ebiggs1]

Oh, BTW, shoot jpg. Not RAW.  Here is one place for jpg over RAW.  

[Waddizzle]

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@ebiggs1 wrote:

Oh, BTW, shoot jpg. Not RAW.  Here is one place for jpg over RAW.  

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Why?  Frames Per Second processing speed?  File size?  I'm pretty sure speeds fits in here somewhere.

[kvbarkley]

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@Waddizzle wrote:

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@ebiggs1 wrote:

Oh, BTW, shoot jpg. Not RAW.  Here is one place for jpg over RAW.  

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Why?  Frames Per Second processing speed?  File size?  I'm pretty sure speeds fits in here somewhere.

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I would guess the no real buffer limit, just mash the shutter and go.