Q: AI Servo on the 20d

[OneManArmy]

I cover sports a lot and got the 20d in part because of the AI Servo mode. But I noticed that, when I use it, none of the autofocus points ever light up. Will the AI Servo mode produce shots as sharp as they would be in one-shot? Thanks

[Adam Hicks]

They never light up because it is in constant focus mode. It also allows you to take shots at any time, without the lit focus point. The idea is things that are moving are constantly being adjusted for focus, you'd hate to hear the thing beep 300 times while you track it :)

You can try the AI Focus mode, which WILL give you a beep and lock onto a still subject, but as soon as that subject moves it switched to AI Servo constant focus mode. Depending on what you're shooting this might be the best of both worlds for ya.

Adam

[defordphoto]

I cover sports a lot and got the 20d in part because of the AI Servo mode. But I noticed that, when I use it, none of the autofocus points ever light up. Will the AI Servo mode produce shots as sharp as they would be in one-shot? Thanks

I shoot motorsports and hence, live, breathe and eat AI Servo. Yes, your shots (can) be as sharp as any other mode.

[PacAce]

I cover sports a lot and got the 20d in part because of the AI Servo mode. But I noticed that, when I use it, none of the autofocus points ever light up. Will the AI Servo mode produce shots as sharp as they would be in one-shot? Thanks

In AI Servo mode, the AF points will not light up, as you have already discovered. The green focus confirmation LED will not light up either. But, if focus has not been achieved, that LED will blink multiple times to let you know that. As far as the sharpness is concerned, there's no reason why shooting in AI Servo mode should not give you the same sharpness as when shooting in one-shot mode, assuming focus has been achieved. The drawback of AI Servo is that is will allow you to release the shutter even when focus has not been achieved, so be sure to give the camera a second to lock in on the subject before releasing the shutter.

[kawter2]

The reason that they don't light up is that in OneShot as soon as it gets focus It stops and notifyies you... "Hey I found the focus, I'm done" With AI it is never done so I guess that is why Canon never sends a confirmation.

AI will be as sharp if not sharper than one-shot because if the subject is moving you have a better chance that your focus is right on the split seccond you hit the shutter release. in one-shot (i have this happen with my kids a lot) the subject can move in the split seccond between focus confirmation and shutter release


*edit* wow this thread moved fast, no posts and by the tuime i submitted it had several :)

[yellow_belly]

You can try the AI Focus mode, which WILL give you a beep and lock onto a still subject, but as soon as that subject moves it switched to AI Servo constant focus mode. Depending on what you're shooting this might be the best of both worlds for ya.I personally wouldnt use AI Focus mode as IMO it does NOT switch to AI Servo in any dependable or predictable way :(

Terry

[defordphoto]

I personally wouldnt use AI Focus mode as IMO it does NOT switch to AI Servo in any dependable or predictable way :(

Terry

Yes. Good point Terry. I never use AI Focus for my shoots. But then again, my MKII doesn't even have it. :)

[kawter2]

Yes. Good point Terry. I never use AI Focus for my shoots. But then again, my MKII doesn't even have it. :)


Yea,it is like Utopia, looks great on paper but in practice......

[OneManArmy]

Thanks guys, I think I'll try it next time.

A similar question: If I'm shooting in AI servo, can I use slightly slower shutter speeds? I normally shoot indoor martial arts and boxing matches around 1/250 or 1/320. I'm wondering if I could slow down a bit with AI Servo or if I'll still need to shoot with fast speeds.

Another question: If I focus in on a person's nose for example, and I hold the shutter down and track them in AI Servo, and all of a sudden the camera changes focus onto their chest, how will I know?

[defordphoto]

I think AI Focus would apply if your subject is stop-go, stop-go, stop-go...

[kawter2]

Thanks guys, I think I'll try it next time.

A similar question: If I'm shooting in AI servo, can I use slightly slower shutter speeds? I normally shoot indoor martial arts and boxing matches around 1/250 or 1/320. I'm wondering if I could slow down a bit with AI Servo or if I'll still need to shoot with fast speeds.

Another question: If I focus in on a person's nose for example, and I hold the shutter down and track them in AI Servo, and all of a sudden the camera changes focus onto their chest, how will I know?
The fact that it is in focus won't affect how fast you need to shoot the action. I would try to hit even 1/400 to stop the motion for sports like basketball etc

[Jon]

A similar question: If I'm shooting in AI servo, can I use slightly slower shutter speeds? I normally shoot indoor martial arts and boxing matches around 1/250 or 1/320. I'm wondering if I could slow down a bit with AI Servo or if I'll still need to shoot with fast speeds.
No, AI Servo is irrelevant to that - you need the fast speeds to minimize camera vibration and stop subject motion during the exposure; it's not trying to follow-focus then. What you might find is that in shooting a burst the shots after the first will be sharper, but that's because the first shot's contending with your pressing the shutter release and any camera motion from that action.

[OneManArmy]

No, AI Servo is irrelevant to that -
I guessed that would be the case...

What you might find is that in shooting a burst the shots after the first will be sharper, but that's because the first shot's contending with your pressing the shutter release and any camera motion from that action.I do that often; I have the shooting mode on continuous for that reason... thanks

[OviV]

Let me just warn you about your type of shooting and what can happen. I shoot LL Baseball. I put the camera in AI Servo when shooting action on the field (kid making a play at ss, kid running the bases, etc.). If I want to get a shot of a kid hitting for example, AI Servo is a bad choice. If the kid moves during his swing and my focus point hits a spot behind him it will cause the camera to refocus and I'll have a blurry kid. I can see this happening with your martial artists as well. In other words, AI Servo is good when the action and motion is predictable but can be hard to work with when you have action in bursts.

Ovi

[defordphoto]

That's when AI Focus would come in real handy.

[OneManArmy]

Oviv, yes I can see that as well. I may have to play around with both modes and see which works best...

[kawter2]

Oviv, yes I can see that as well. I may have to play around with both modes and see which works best...


Use one-shot if the focal point will stay on the same focal plane (i.e. they are moving left and right up and down,) use AI servo when the focal plane is going to change (i.e. forward and backwards)

[timmyquest]

Yes. Good point Terry. I never use AI Focus for my shoots. But then again, my MKII doesn't even have it. :)

My girlfriends elan 7n does, from what i can tell, it is worthless. By the time the camera decides that it needs to switch into AI servo...the subject may very well be gone.

[timmyquest]

Thats when its usefull to change AF to the * button.

Let me just warn you about your type of shooting and what can happen. I shoot LL Baseball. I put the camera in AI Servo when shooting action on the field (kid making a play at ss, kid running the bases, etc.). If I want to get a shot of a kid hitting for example, AI Servo is a bad choice. If the kid moves during his swing and my focus point hits a spot behind him it will cause the camera to refocus and I'll have a blurry kid. I can see this happening with your martial artists as well. In other words, AI Servo is good when the action and motion is predictable but can be hard to work with when you have action in bursts.

Ovi

[OneManArmy]

Thats when its usefull to change AF to the * button.Elaborate?

[Jon]

CF-4, and set to "1". The lens will auto-focus when you press the * button and take the picture on shutter release. Let go of the * and the lens will stop focussing.

[PacAce]

My girlfriends elan 7n does, from what i can tell, it is worthless. By the time the camera decides that it needs to switch into AI servo...the subject may very well be gone.

The point of AI Focus is to focus on a subject and then lock on it so tha it doesn't have to keep focusing on it. Then, if the subject decides to move towards or away from the camera, it will switch to AIServo mode to track the subject and continue to keep it in focus. AI Focus is pretty reactive to movement so the only way I can see the camera not being able to keep up is when the subject is really moving fast or is very close to the camera.

[kawter2]

The point of AI Focus is to focus on a subject and then lock on it so tha it doesn't have to keep focusing on it. Then, if the subject decides to move towards or away from the camera, it will switch to AIServo mode to track the subject and continue to keep it in focus. AI Focus is pretty reactive to movement so the only way I can see the camera not being able to keep up is when the subject is really moving fast or is very close to the camera.


In theory it sounds great, IMO it has never worked that well on any camera I have tried it on

[PacAce]

In theory it sounds great, IMO it has never worked that well on any camera I have tried it on

Have always worked fine for me in situations where I use them. But, of course, when the need has arisen, I've also used AI Servo instead of AI Focus.

[timmyquest]

Have always worked fine for me in situations where I use them. But, of course, when the need has arisen, I've also used AI Servo instead of AI Focus.


Maybe i'm just biased as i think the CFN that changes * to focus kind of gives the photographer the same thought process that AI focus does, only smarter.

[PacAce]

Maybe i'm just biased as i think the CFN that changes * to focus kind of gives the photographer the same thought process that AI focus does, only smarter.
All CFn04 gives you is different button to press (the "*" button) instead of pressing on the shutter release button. However, AF in either SingleShot or AIServo will still function the same way no matter which button you use. I doubt you can really simulate the AIFocus using the '"*" button. The closest you'll get to it is by setting AF to AIServo. You would then press the "*" to get the initial lock and the let go of the button. Now, are you trying to tell me that your reflex is go fast that you can press the "*" button again much more quickly than the camera can as soon as the subject starts moving so that you can track the subject and keep it in focus? :)

[CyberDyneSystems]

OneManArmy,

You want to have a look at the last link in the -=20D Info FAQ Thread=- (http://photography-on-the.net/forum/showthread.php?t=44168)

... the link about favorite custom functions.
Many of the high speed action shooters on the forum, (or birders like myself) use CF#4-1 to take best advantage of AI servo... ;)

[CyberDyneSystems]

And Leo... yes.. with practice using CF#4-1 you can switch MUCH faster than the camera can switch from Single-shot to AI-servo using the AI-focus setting... and much more predictably as well ;)

[timmyquest]

All CFn04 gives you is different button to press (the "*" button) instead of pressing on the shutter release button. However, AF in either SingleShot or AIServo will still function the same way no matter which button you use. I doubt you can really simulate the AIFocus using the '"*" button. The closest you'll get to it is by setting AF to AIServo. You would then press the "*" to get the initial lock and the let go of the button. Now, are you trying to tell me that your reflex is go fast that you can press the "*" button again much more quickly than the camera can as soon as the subject starts moving so that you can track the subject and keep it in focus? :)

I feel that * plus AI servo will give you the effect.

Lock onto an image, release the button, if the subject starts to move, push the button and aquire focus again.

People talk about how you should use one shot for static objects, but i find that AI servo works just fine just so long as you dont hold the button down (like you would if the focus was attatched to the shutter button)

[HKFEVER]

That's when AI Focus would come in real handy.
Is AI Focus same as one shot mode?:cry:

[timmyquest]

Is AI Focus same as one shot mode?:cry:


PacAce did a nice job explaining it a few posts up
The point of AI Focus is to focus on a subject and then lock on it so tha it doesn't have to keep focusing on it. Then, if the subject decides to move towards or away from the camera, it will switch to AIServo mode to track the subject and continue to keep it in focus. AI Focus is pretty reactive to movement so the only way I can see the camera not being able to keep up is when the subject is really moving fast or is very close to the camera.

[kawter2]

Maybe i'm just biased as i think the CFN that changes * to focus kind of gives the photographer the same thought process that AI focus does, only smarter.


Yep totally agree!!!

[HKFEVER]

PacAce did a nice job explaining it a few posts up
So AI Focus is C.FN-04 Shutter button/AE lock button function?:cry:

[kawter2]

no C.FN-04 makes the *button do the focusing. the shutter button will only get the exposure info.


If you use that and you enable AI-servo. you can hold down * or just tap it to get focus again. It works independently from the shutter release

[HKFEVER]

no C.FN-04 makes the *button do the focusing. the shutter button will only get the exposure info.


If you use that and you enable AI-servo. you can hold down * or just tap it to get focus again. It works independently from the shutter release
Is this call AI Focus?:cry:

[timmyquest]

Is this call AI Focus?:cry:


Does someone have a hard time reading? :confused:

[HKFEVER]

Does someone have a hard time reading? :confused:
Sorry to bother you, because I can't find this "AI Fouce" function in the manual.

So is this call " AI Focus "? :o

[timmyquest]

Sorry to bother you, because I can't find this "AI Fouce" function in the manual.

So is this call " AI Focus "? :o


Sorry, i didnt notice your sig. I"m pretty certain the 1D, 1DMKII 1Ds and 1Ds MKII do not have "AI servo".

PS, your not bothering anyone. I was just giving you a hard time.

[HKFEVER]

Sorry, i didnt notice your sig. I"m pretty certain the 1D, 1DMKII 1Ds and 1Ds MKII do not have "AI servo".

PS, your not bothering anyone. I was just giving you a hard time.
1D, I am not sure.

But my previous 1D MKII and current 1Ds MKII both has AI Servo. So what does this mean? Can I set up AI Focus in 1Ds MKII?:lol:

[timmyquest]

1D, I am not sure.

But my previous 1D MKII and current 1Ds MKII both has AI Servo. So what does this mean? Can I set up AI Focus in 1Ds MKII?:lol:

Bah, i'm just confusing you more, i meant AI-Focus. THey do have AI-Servo

[HKFEVER]

Bah, i'm just confusing you more, i meant AI-Focus. THey do have AI-Servo
Which Canon has this AI Focus?
I wonder why Type 1 Body don't have AI Focus?

[timmyquest]

Which Canon has this AI Focus?

Their medium level, prosumer bodies. (not sure about pre 10D's) the 10D, 20D, elan 7n all have it. I'm pretty sure the rebels (35mm) do not.


I wonder why Type 1 Body don't have AI Focus?

If i had to guess, it would be because it is worthless :D

[HKFEVER]

Their medium level, prosumer bodies. (not sure about pre 10D's) the 10D, 20D, elan 7n all have it. I'm pretty sure the rebels (35mm) do not.



If i had to guess, it would be because it is worthless :D
I like this line.:lol:

How can I setup the 1D MKII and 1DsMKII to have the similar effect as the 20D's AI Focus function?:rolleyes:

[timmyquest]

Like i said on the other page:

(custom function 4 btw)
I feel that * plus AI servo will give you the effect.

Lock onto an image, release the button, if the subject starts to move, push the button and aquire focus again.

People talk about how you should use one shot for static objects, but i find that AI servo works just fine just so long as you dont hold the button down (like you would if the focus was attatched to the shutter button)

[HKFEVER]

Like i said on the other page:

(custom function 4 btw)
Thank you, I will try it with my shark in the pool.:p

[PacAce]

CDS and Timmy,

I'm not saying that you can't use the "*" and AIServo to do the same thing that AIFocus does. I'm just saying that the camera will do it much faster than your reflexes can react. What I'm also saying is that you can also do the same thing without having to use the "*" button by just using the shutter release button and AIServo.

I'm not defending the use of AIFocus over AIServo. I use AIServo 99% of the time when I'm not using Single Shot. However, what I am saying is that AIFocus does have it's use and that it's not useless. That's all.

Cheers. :)

[PacAce]

Is this call AI Focus?:cry:

Actually, it's something you don't have to worry about becausee the 1D series camera does not have this function. It's only available in cameras such as the 10D, the DRebel and I think the 20D and a few others.

[Oops. After getting to the end of the thread, I see that this has already been addressed. Sorry for the redundancy.]

[timmyquest]

Actually, it's something you don't have to worry about becausee the 1D series camera does not have this function. It's only available in cameras such as the 10D, the DRebel and I think the 20D and a few others.

[Oops. After getting to the end of the thread, I see that this has already been addressed. Sorry for the redundancy.]

Is AI focus what the rebel is in during "creative" modes?

[OneManArmy]

OK guys, here's another questoin about AI Servo.

When shooting action, I'm indoors and often have to use a large aperture, which reduces my dept of field, and I often have to throw away photos becuase the focus is on the person's chest or shoulders and not their face. So if AI Servo doesn't light up focus points, then WHAT exactly is in focus when it takes the shot?? Thanks

[OviV]

I always use the center focus point with AI Servo.

[OneManArmy]

I always use the center focus point with AI Servo.
But by using the center point, aren't you kind of limited on your framing selections?

[timmyquest]

But by using the center point, aren't you kind of limited on your framing selections?

Perhaps, but the center point is the most accurate, and typically in sports, unless it's a special shot, the subject is supose to fill the entire frame anyways.

[OviV]

Like you said, you really can't tell easily which focus point is being used. You want to be sure. Like Timmy said, it is the most accurate. Also, if you have time to frame the shot you should probably use one shot focus or use the custom function mentioned above to enable * focusing.

Ovi

[PacAce]

Is AI focus what the rebel is in during "creative" modes?

Yes, and in the green box mode.

[PacAce]

But by using the center point, aren't you kind of limited on your framing selections?

You can also use all the AF points by setting it to auto AF selection. When the AF selection is set to auto and AF drive is set to AIServo, the camera will use the center point for the initial focusing. Once focusing is obtained, you can reframe the image and still have the subject in focus. If the subject moves and it's covered by any of the AF points, the camera will be able to track the subject with any of the AF points and keep it in focus. This won't work, though, if the subject is so small that it can only be covered by one AF point at a time.

[BigRed450]

CDS and Timmy,

I'm not saying that you can't use the "*" and AIServo to do the same thing that AIFocus does. I'm just saying that the camera will do it much faster than your reflexes can react. What I'm also saying is that you can also do the same thing without having to use the "*" button by just using the shutter release button and AIServo.

I'm not defending the use of AIFocus over AIServo. I use AIServo 99% of the time when I'm not using Single Shot. However, what I am saying is that AIFocus does have it's use and that it's not useless. That's all.

Cheers. :)

In order to realize the value and ultimate focus control allowed by using the "*" button, you must try it out. It makes a world of difference and certainly much more control is gained. For instance, in A1 Servo mode with shudder button focus you must depress the shudder botton 1/2 way to activate AF which also activates AE. This can get quite tricky in varying light conditions with fast action. That is where the difference lies. By selecting CF n-04 and initiating the * button for focus control, you have now separated these 2 functions to work independantly allowing you to have tracking, predictive focus as well as Focus Lock while still being able to allow AE changes and visa versa.. There is no need to depress the shutter button until you are ready take the image.

I too only use the Center AF for sports and fast action.... Much more predictable and reliable focus IMHO.

[OneManArmy]

I too only use the Center AF for sports and fast action.... Much more predictable and reliable focus IMHO.
I tried that on advice, and the issue I ran into was, in low light and wide apertures the DOF is narrow and with center focus on their face, I was'nt getting what I needed to get in the frame. Suggestions?

[PacAce]

In order to realize the value and ultimate focus control allowed by using the "*" button, you must try it out. It makes a world of difference and certainly much more control is gained. For instance, in A1 Servo mode with shudder button focus you must depress the shudder botton 1/2 way to activate AF which also activates AE. This can get quite tricky in varying light conditions with fast action. That is where the difference lies. By selecting CF n-04 and initiating the * button for focus control, you have now separated these 2 functions to work independantly allowing you to have tracking, predictive focus as well as Focus Lock while still being able to allow AE changes and visa versa.. There is no need to depress the shutter button until you are ready take the image.

I too only use the Center AF for sports and fast action.... Much more predictable and reliable focus IMHO.

And I wasn't debating the merits of using the "*" button over the shutter release button. All I was saying is that you don't have to use the "*" button to simulate the AI Focus mode and that's all. And, as far as using the "*" button for focusing is concerned, I was using it almost from the get-go when I got my 10D when the first batches of 10Ds hit the market so I've very familiar with the ins and outs of using the "*" button. :)

[BigRed450]

And I wasn't debating the merits of using the "*" button over the shutter release button. All I was saying is that you don't have to use the "*" button to simulate the AI Focus mode and that's all. And, as far as using the "*" button for focusing is concerned, I was using it almost from the get-go when I got my 10D when the first batches of 10Ds hit the market so I've very familiar with the ins and outs of using the "*" button. :)

Sorry PacAce didn't mean to offended you. Just merely wanted to point out the reasons why most of use the * button for AF

[BigRed450]

I tried that on advice, and the issue I ran into was, in low light and wide apertures the DOF is narrow and with center focus on their face, I was'nt getting what I needed to get in the frame. Suggestions?

The center focus point is the strongest (most sensitive) of all. If in low light you are having trouble with this one it will only be worse with the other points. My suggestion then would be to increase your ISO to 1600 or 3200 so you can close down your aperature and get a larger DOF and invest in a quality de-noising program such as Neat Image... I have used ISO 1600 and 3200 for indoor arena shoots with my 100-400..

[PacAce]

Sorry PacAce didn't mean to offended you. Just merely wanted to point out the reasons why most of use the * button for AF

No offense was taken. I just wanted to clarify the points I was trying to make. :)

[spoolin_photography]

AI Servo works really well for me as i mainly do automotive photography and I am usually constantly changing my zoom as I am tracking a car

Cheers
Shane

[Patrick 10D]

They never light up because it is in constant focus mode. It also allows you to take shots at any time, without the lit focus point. The idea is things that are moving are constantly being adjusted for focus, you'd hate to hear the thing beep 300 times while you track it :)

Interesting.

Last night, I returned from a three week trip to the US. While I was there, I finally had time to use my 20D with all of my different glass. I managed to shoot my 2 GB card full!

While at SeaWorld, and shooting Shamu with my 70-200 2.8, I noticed that I was not getting any focus lights (the red ones) with AI Servo mode. I was slightly worried that all of my action pictures would not turn out focused.

The next day, while shooting USN Aircraft Carriers on Coranado Island, with the same lens + 1.4 extender, in One Shot mode, everything was back to "normal".

I was tempted to post a question about this issue ... only to find this thread! Thanks.

BTW, pictures turned out fine, the trip was great, but jet lag SUCKS!

.

[edsarkiss]

maybe i can state this whole "focus on the * button" thing more clearly:

1) set CF-04 to 1 (shutter == AE Lock / * == AF )
2) set the focus mode to AI Servo

now aim the camera at something. press the shutter halfway -- the camera will not focus. it _will_ take a meter reading and hold that exposure as long as you hold the shutter button.

press the * button -- now you are continuously focusing. release the * button -- no longer focusing.

in the martial arts example, you would put the person's face in the center of the frame, and focus with *. when you want to take a photo, release *, recompose (the camera will no longer change the focus) and press the shutter button fully. the camera will take the picture. hopefully the person hasn't moved much between releasing * and pressing the shutter button ;-)

the whole reason for making this change is to decouple focusing from the shutter button. in the example above, with stock settings (focus on the shutter button) the camera would always refocus on the person's chest when you go to take the picture.

you can also set CF-04 to "2" use the shutter to focus as normal, and to use the * button as "AF lock", but then you lose any AE lock capability. the value of "1" has proven to be the best compromise to a lot of people.

hopefully that makes things clearer.