Too much shutter lag with digital rebel............

[Gary Vrooman]

If you shoot in sports mode, Al-servo is always active. That's what I do when I'm shooting birds in flight and my percentage of OOF shots is pretty low. In sports mode you give up a lot of control, and because of the ISO400 upper limit you need to have sufficient ambient light, but in the right conditions it works wonderfully.

I guess i can't complain since it's a whole lot better than most
non slr cameras, but there is definately shutter lag or i'm losing
my mind.

 

[PaulyOly]

If you achieve focus lock, hear a beep, and then complete the
press, then surely the bird has shifted forwards to SOME degree
from the point in time the focus lock is achieved and the actual
shutter depress takes place.. this is where predictive auto focus
might come positively in play? From the time you process the
beep in your head and until you actually depress the shutter
release, some measurable time elapses (any care to venture a guess
how much, on average?.. but probably at LEAST as much time, if not
more, than the actual shutter lag itself!)... I don't know the
average time this takes a typical person off the top of my head,
but I do know it's very likely measurable enough to allow the bird
to move towards you. Then, depending upon the DOF achieved, and
considering the DOF is typically shallower towards the front and
deeper towards the back, the directional movement forward is
certainly the direction one would expect this to show in a more
pronounced manner, I would think. You also mentioned that the ones
where the bird was closer were worse.. and I'd expect so, since the
DOF was likely even shallower unless you changed aperture on those
closer shot to maintain a DOF roughly consistent with the further
away shots(?).. again, forward movement of the bird plus the time
elapsing factors mentioned above are all at work and, if the DOF
was shallower, then the timing is even shorter before the bird
leaves the focused zone.

So, add the brain-hears-beep-to-finger-completing-release delay,
the bird moving towards you, into the shallower portion of DOF, and
the actual shutter lag from a prefocused 300D and you are probably
seeing the combined results in the OOF bird, with the feet
appearing more in focus by the time the shot is actually taken?
Using a faster shutter speed will help "some", but is not likely to
be a cure-all for the factors at work. It will only solve/aid a
small portion of the issue.. by reducing the slice of time during
which the shutter is open and shortening up the distance the bird
will travel during that period of time.. but even at 1/500 or
1/640, I don't think this is the chief culprit. the rest of the
delays will still exist.

You've probably already checked this.. but, where is the focus
point recorded as being? Did you check the shots in Canon's File
Viewer Utility to see where the red box(es) are? It might give
some more hard data to consider.

At any rate, I'm not convinced that the camera involved is the
chief contributor. Certainly, it's one contributor and a faster
camera (1D, for example) would help.. but probably not enough to
eliminate the issue. It would be a $5000 disappointment until
other factors are reduced enough to compensate for their own
influences on the OOF condition.

Just my opinion.. I could be wrong, but I believe the factors I
mentioned are all at work and all working against obtaining an
in-focus shot. It's not an impossible task to overcome, I don't
believe, just not an easy one with a single magic bullet (like a
faster responding camera). I'd love to hear from some pro Sports
shooters or someone else more keenly aware of all the things
involved and working against the shooter in these situations and
how to best conquer them? Likely that "practice, practice,
practice" (to improve technique, lower human response time, find
optimal settings), "shoot many, many shots" and "use continuous
shooting mode" will be buried inside of that advice?! ;-)

BTW, I love the shots and certainly can appreciate the difficulty
involved in getting them at all, let alone perfectly. Keep up the
good (hard) work!

icmp

I guess i can't complain since it's a whole lot better than most
non slr cameras, but there is definately shutter lag or i'm losing
my mind. I spent 4 hours yesterday shooting osprey inflight shots
and almost every shot of the bird flying towards me was slightly
out of focus. If he was flying parallel to me then it was sharp.
My camera/lens might be backfocusing sligtly as well since it seems
if it's flying away from me they tend to be sharper.

heres' the best shot flying towards me from today.



now here's one of the bird flying parallel to me.



kind of hard to tell with these processed pics, i'll follow this up
with some unprocessed 100% crops.
--
http://www.pbase.com/paulyoly/root

--
http://www.pbase.com/paulyoly/root



Some of you are not reading my posts, i do not prefocus first then press the shutter button, i press the shutter button!!! There is no elapse time!

 

[Kai Hui]

I guess those birds are smart. They might think that you are pointing a gun to them.

This is my experience. I can walk reasonably close to some birds without eye contact. As soon as I stare at them, they just fly away. How smart they are!

Kai

cool He should have really nice bokeh with that lens. My lens
does not have a tripod mount and to get one cost 109$ so I'll skip
it at least for now. but it should be better for me to use a
monopod.

Do you handhold yours?

where do you live exactly? Here I have a hard time getting
anywhere near those osprey. They drive me nuts because people walk
near them without camera and they don't fly away..as soon as I try
to get close with my camera they fly away. I hope they will like
the color of the L lens better..maybe they think that a black thing
is a gun? not sure

--
I am a newbie in photographing. Some of my not-so-great shots are here:
http://www.pbase.com/kaihui

 

[PaulyOly]

Servo mode has predictive focusing that will continue to focus baed
on the motion during this lag period.

Gene

I guess i can't complain since it's a whole lot better than most
non slr cameras, but there is definately shutter lag or i'm losing
my mind. I spent 4 hours yesterday shooting osprey inflight shots
and almost every shot of the bird flying towards me was slightly
out of focus. If he was flying parallel to me then it was sharp.
My camera/lens might be backfocusing sligtly as well since it seems
if it's flying away from me they tend to be sharper.

heres' the best shot flying towards me from today.



now here's one of the bird flying parallel to me.



kind of hard to tell with these processed pics, i'll follow this up
with some unprocessed 100% crops.
--
http://www.pbase.com/paulyoly/root

--
Gene (the hawkman) - Walk softly and carry a big lens

Please visit my galleries at: http://www.pbase.com/gaocus/

If you say it is so then i believe you, but i don't remember reading this anywhere. So the camera actually focuses infront of your shot? I will try this today, fortunately for me i can kick in AI servo by simply focusing on a rock and twisting the focus ring on the 400 f5.6L.
--
http://www.pbase.com/paulyoly/root

 

[Kai Hui]

I would assume on a camera with zero shutter lag i
should be able to take a pic of a car coming straight at me and it
be sharp assuming my shutter speed was fast enough.

I guess it is a good assumption, but that might be your last sharp photo in your life

Kai

 

[Kai Hui]

Hi, Paul,
I think what you observed is true in general.

Suppose the lag time between the time you achieve the AF and the time you complete the shot is 0.1 sec (100ms). The speed of flying birds is about 20 meter/sec (ball park). So in that 0.1 sec, the bird has already flew 2 meters (about 6 feet). That's beyond DOF.

When the bird flies laterally, the distance between the bird and your camera remains unchanged (or very small change). What you have in focus will still be in focus after 0.1 sec. However, if the bird flies towards or out of your camera, then the distance between the bird and your camera has changed completly (as far as 6 feet) in 0.1 sec. Then you are hopeless.

Fast cameras will help but it is not a total cure.

The best way, I think, is the AI servo, which tracks moving objects in focus. However, our 300D is not very good at AI servo which can only be found in "sports mode". Even in sports mode, AI servo is kind of hit and miss, but that's the only thing we have.

I would suggest you try sports mode for some shots next time. As a matter of fact, that's what AI servo is designed for.

I am relatively new in photographing, so take my advice with grain of salt.

Kai

 

[Kai Hui]

You have ospreys flying on the street? Do you live in a zoo or something?

The second shot looks very sharp to me.

Kai

 

[Jarl Sandberg]

Sometimes I belive that we put unreasonable requirements on our equipments. If I got one or two great shots and 10-20 throwaways after my photo sessions I consider it a good session. Count the good ones and not the ones that "got away".

My quess is that the problem with the 300D isn't so much the shutter lag but the frame speed and buffer size.

And if you could save the pic with postprocessing... Well, you got the shot after all.

Regards

--jalle

I guess i can't complain since it's a whole lot better than most
non slr cameras, but there is definately shutter lag or i'm losing
my mind. I spent 4 hours yesterday shooting osprey inflight shots
and almost every shot of the bird flying towards me was slightly
out of focus. If he was flying parallel to me then it was sharp.
My camera/lens might be backfocusing sligtly as well since it seems
if it's flying away from me they tend to be sharper.

heres' the best shot flying towards me from today.



now here's one of the bird flying parallel to me.



kind of hard to tell with these processed pics, i'll follow this up
with some unprocessed 100% crops.
--
http://www.pbase.com/paulyoly/root

 

[linden7179]

Yes, I do not have a 300D. But I have an Elan II. There is no focus beep if you are using servo focus mode. It predicts the movement. It works great.

Simon

else you will see shutter lag between when you half depress the
shutter button and AF locks, and when you fully depress it and the
shutter (after lag) fires.

Servo mode has predictive focusing that will continue to focus baed
on the motion during this lag period.

oh really?

I have to try this.

 

[Hawkman]

Hi Paul,

Yes, it does predictive focusing in continuos frame, AI servo. In single frame it doesn't. In single frame the lens quits focusing when the shutter button is fully depressed, and you will get the lag effect. Canon calls this "release priority". In fact, as the note below mentions, the first frame of a continous is shot is in release priority so it can be out of focus due to lag too. However the second and successive frames use "focus priority" which is predictive (so always plan to fire off two shots at least).

The tech note in the link above says the algorithm takes into account the subject speed, the AF lag and the [shutter] release lag in predicting the focus.

Here is a link to a canon tech not on how AI servo works:

http://photonotes.org/other/ai-servo.html

Also, the 10d manual states:

"AI servo: With Predictive AF, the camera can also focus track a subject which steadily approaches or retreats from the camera."

And under predictive AF:

"If the subject approaches or retreats from the camera at a constant rate. the camera tracks the subject and predicts the focusing distance immediately before the image is captured. This is for obtaining the correct focus at the moment of exposure."

I always shoot flight shots in continuous frame, AI servo, and fire off several shots each time.

Cheers,
Gene

Servo mode has predictive focusing that will continue to focus baed
on the motion during this lag period.

Gene

I guess i can't complain since it's a whole lot better than most
non slr cameras, but there is definately shutter lag or i'm losing
my mind. I spent 4 hours yesterday shooting osprey inflight shots
and almost every shot of the bird flying towards me was slightly
out of focus. If he was flying parallel to me then it was sharp.
My camera/lens might be backfocusing sligtly as well since it seems
if it's flying away from me they tend to be sharper.

heres' the best shot flying towards me from today.



now here's one of the bird flying parallel to me.



kind of hard to tell with these processed pics, i'll follow this up
with some unprocessed 100% crops.
--
http://www.pbase.com/paulyoly/root

--
Gene (the hawkman) - Walk softly and carry a big lens

Please visit my galleries at: http://www.pbase.com/gaocus/

If you say it is so then i believe you, but i don't remember
reading this anywhere. So the camera actually focuses infront of
your shot? I will try this today, fortunately for me i can kick in
AI servo by simply focusing on a rock and twisting the focus ring
on the 400 f5.6L.
--
http://www.pbase.com/paulyoly/root

--
Gene (the hawkman) - Walk softly and carry a big lens

Please visit my galleries at: http://www.pbase.com/gaocus/

 

[Doug Kerr]

Pauly,

I'm talking about the focus lock beep, so we are talking about the
same thing, i don't wait for a focus lock beep, i just push the
button, i have the picture fairly well infocus from prefocusing and
then start pushing the button as i've stated before, so it's either
miss focus or shutter lag, i'm thinking shutter lag, so what is the
shutter lag time on the rebel?

On my 300D, if I have prefocused with half press, then from the time I full press the shutter release until the shot is taken is about 120 ms.

If I do a full press to begin with, I don't know what the time is from the beep until the shutter is fired. I had never been thinking about focus implications of shutter release delay.

I assume AI servo can't help us here, as doubtless it stops tracking once the shot is committed by the full press (since, for example, the mirrors and diaphragm start to move then).

Best regards,

Doug

 

[Kai Hui]

Man, this EOS system is sure complicated.

Now, my question is how good is the AI servo function on 300D.

Kai

Yes, it does predictive focusing in continuos frame, AI servo. In
single frame it doesn't. In single frame the lens quits focusing
when the shutter button is fully depressed, and you will get the
lag effect. Canon calls this "release priority". In fact, as the
note below mentions, the first frame of a continous is shot is in
release priority so it can be out of focus due to lag too. However
the second and successive frames use "focus priority" which is
predictive (so always plan to fire off two shots at least).

The tech note in the link above says the algorithm takes into
account the subject speed, the AF lag and the [shutter] release
lag in predicting the focus.

Here is a link to a canon tech not on how AI servo works:

http://photonotes.org/other/ai-servo.html

Also, the 10d manual states:

"AI servo: With Predictive AF, the camera can also focus track a
subject which steadily approaches or retreats from the camera."

And under predictive AF:

"If the subject approaches or retreats from the camera at a
constant rate. the camera tracks the subject and predicts the
focusing distance immediately before the image is captured. This is
for obtaining the correct focus at the moment of exposure."

I always shoot flight shots in continuous frame, AI servo, and fire
off several shots each time.

Cheers,
Gene

Servo mode has predictive focusing that will continue to focus baed
on the motion during this lag period.

Gene

I guess i can't complain since it's a whole lot better than most
non slr cameras, but there is definately shutter lag or i'm losing
my mind. I spent 4 hours yesterday shooting osprey inflight shots
and almost every shot of the bird flying towards me was slightly
out of focus. If he was flying parallel to me then it was sharp.
My camera/lens might be backfocusing sligtly as well since it seems
if it's flying away from me they tend to be sharper.

heres' the best shot flying towards me from today.



now here's one of the bird flying parallel to me.



kind of hard to tell with these processed pics, i'll follow this up
with some unprocessed 100% crops.
--
http://www.pbase.com/paulyoly/root

--
Gene (the hawkman) - Walk softly and carry a big lens

Please visit my galleries at: http://www.pbase.com/gaocus/

If you say it is so then i believe you, but i don't remember
reading this anywhere. So the camera actually focuses infront of
your shot? I will try this today, fortunately for me i can kick in
AI servo by simply focusing on a rock and twisting the focus ring
on the 400 f5.6L.
--
http://www.pbase.com/paulyoly/root

--
Gene (the hawkman) - Walk softly and carry a big lens

Please visit my galleries at: http://www.pbase.com/gaocus/

--
I am a newbie in photographing. Some of my not-so-great shots are here:
http://www.pbase.com/kaihui

 

[Kai Hui]

It gives AI servo mode on 300D, but has extremely limited explanation on AI servo function in the manual. Do they expect users to figure all these out on their own?

Kai

 

[The Big Bad]

Now I use a 10D and dont use my shutter button for anything except to trigger the shutter. I use the AE lock button on the back of the camera to AF. works the same as a half press of the actual shutter button.

lets my shutter fire anytime I want, in focus or not

Anyways, what your having happen is that when you take you release the shutter button and then press it again, the camera is having to AF between each frame. the 10D/300D arent blazing quick with the AF as im sure you realize

Try this, switch your lens to MF, set the shutter speed up pretty high such as 1/1000th and see just how quick the responce is, its basically instant for all measureable purposes

Also keep in mind with servo mode AF, the body is trying to predict where the focus should be for each frame. It of course wouldnt work to lock focus where the subject is at the itme of focus since in the time it locks and takes the shot, an object in motion is not always in focus.

the 1D is alot faster at this and with the right lens, such as a 300 2.8, it can track and predictively focus on a subject moving 186 MPH at it. So basically its able to change the focus between each shot at 8 FPS. Amazing huh, thats what all that money buys you.

--
http://www.pbase.com/bigbad

 

[Daniella68313]

I guess I still am confused. Doesn't AI focus on the 300d do the
equivalent of AI focu on the 10d, that is use oneshot if no motion
is detected and kick in servo if it is?

oh and does that work for you? does not work for 90% of the people. The problem is that you can change that with the 10D so why bother? we just can't change this. it's up to the camera.

In that case you should be

able to take several sequential shots (in continuous frame mode)
that are in focus once AI kicks in servo mode as long as you keep
the AF point on the subject. Have you tried half depressing the
shutter, track the bird for a second, then fully depress the
shutter? That way predictive focusing should kick in and cover the
lag. Perhaps I am still misunderstanding what you are doing or how
the 300d operates? - Gene

problem is getting the damn thing to kick when needed and not to kick when not needed. it has a mind on its own.

tracking the birds unless there were against the sky. I'll have to
check my harddrive tommorrow, i've got to go to bed. I do not take
several shots in sequence without refocusing, they would surely be
out of focus after the first shot, i'm not prefocusing either, i
push the shutter button fully with the center focus point over the
bird. Does anyone know the actual lag time? How about for the 10d?

check out my messages in this thread. 128ms for the 300d and 68 for the 10D.

--
Gene (the hawkman) - Walk softly and carry a big lens

Please visit my galleries at: http://www.pbase.com/gaocus/

--
Minë Corma hostië të ilyë ar mordossë nutië të
Mornórëo Nóressë yassë i Fuini caitar.
Un thoron arart’a s’un hith mal’kemen ioke.
Saurulmaiel

 

[Hawkman]

I believe it should be the same as the 10d, except you cannot force it to be in AI-servo, its always in AI focus and decides between oneshot or servo.

Yes, its complicated but without the predictive focusing, you will experience OOF shots due to shutter/aperature lag when something is moving towards or away from you fast enough (unless you can manage to prefocus manually).

Gene

Now, my question is how good is the AI servo function on 300D.

Kai

Yes, it does predictive focusing in continuos frame, AI servo. In
single frame it doesn't. In single frame the lens quits focusing
when the shutter button is fully depressed, and you will get the
lag effect. Canon calls this "release priority". In fact, as the
note below mentions, the first frame of a continous is shot is in
release priority so it can be out of focus due to lag too. However
the second and successive frames use "focus priority" which is
predictive (so always plan to fire off two shots at least).

The tech note in the link above says the algorithm takes into
account the subject speed, the AF lag and the [shutter] release
lag in predicting the focus.

Here is a link to a canon tech not on how AI servo works:

http://photonotes.org/other/ai-servo.html

Also, the 10d manual states:

"AI servo: With Predictive AF, the camera can also focus track a
subject which steadily approaches or retreats from the camera."

And under predictive AF:

"If the subject approaches or retreats from the camera at a
constant rate. the camera tracks the subject and predicts the
focusing distance immediately before the image is captured. This is
for obtaining the correct focus at the moment of exposure."

I always shoot flight shots in continuous frame, AI servo, and fire
off several shots each time.

Cheers,
Gene

Servo mode has predictive focusing that will continue to focus baed
on the motion during this lag period.

Gene

I guess i can't complain since it's a whole lot better than most
non slr cameras, but there is definately shutter lag or i'm losing
my mind. I spent 4 hours yesterday shooting osprey inflight shots
and almost every shot of the bird flying towards me was slightly
out of focus. If he was flying parallel to me then it was sharp.
My camera/lens might be backfocusing sligtly as well since it seems
if it's flying away from me they tend to be sharper.

heres' the best shot flying towards me from today.



now here's one of the bird flying parallel to me.



kind of hard to tell with these processed pics, i'll follow this up
with some unprocessed 100% crops.
--
http://www.pbase.com/paulyoly/root

--
Gene (the hawkman) - Walk softly and carry a big lens

Please visit my galleries at: http://www.pbase.com/gaocus/

If you say it is so then i believe you, but i don't remember
reading this anywhere. So the camera actually focuses infront of
your shot? I will try this today, fortunately for me i can kick in
AI servo by simply focusing on a rock and twisting the focus ring
on the 400 f5.6L.
--
http://www.pbase.com/paulyoly/root

--
Gene (the hawkman) - Walk softly and carry a big lens

Please visit my galleries at: http://www.pbase.com/gaocus/

--
I am a newbie in photographing. Some of my not-so-great shots are
here:
http://www.pbase.com/kaihui

--
Gene (the hawkman) - Walk softly and carry a big lens

Please visit my galleries at: http://www.pbase.com/gaocus/

 

[Daniella68313]

well, perhaps you should try a 300d and then you will understand taht it does not work as a 10d.

You just cannot force the camera to use AI servo easily. sometimes it does sometimes it don't.

You can use the servo in sport mode but then you loose everything else..ISO, shutter, F, WB..you name it..not even raw support.

read the dpreview review for the 300d and you will have a better idea.

Thats what I am confused about. What Paul is doing as he describes
it, by fully depressing the shutter and not continuously tracking
and taking a sequence of shots, sounds like attempting to get
oneshot out of AI focus mode on a moving subject, which I am not
sure what the outcome would be, but if succeeded, would be affected
by shutter lag. But it sounds like he had a long day, so maybe his
description isn't accurate. Anyhow, tomorrow.

Gene

10D and 300d don't work the same way.

You said single shot Paul. I took that as oneshot, which on the 10d
that is AI servo/AI off, no predictive focusing at all. I think you
meant single frame as opposed to continuous frame. Since you are
using AI fousing that should take care of any shutter lag, unless
the AI it hasn't kicked into servo mode. That may be a possibility.
I use the servo mode on the 10D and get good results coming, going
or sideways.

Gene

else you will see shutter lag between when you half depress the
shutter button and AF locks, and when you fully depress it and the
shutter (after lag) fires.

Servo mode has predictive focusing that will continue to focus baed
on the motion during this lag period.

oh really?

I have to try this.

--
Gene (the hawkman) - Walk softly and carry a big lens

Please visit my galleries at: http://www.pbase.com/gaocus/

--
Gene (the hawkman) - Walk softly and carry a big lens

Please visit my galleries at: http://www.pbase.com/gaocus/

--
Minë Corma hostië të ilyë ar mordossë nutië të
Mornórëo Nóressë yassë i Fuini caitar.
Un thoron arart’a s’un hith mal’kemen ioke.
Saurulmaiel

--
Gene (the hawkman) - Walk softly and carry a big lens

Please visit my galleries at: http://www.pbase.com/gaocus/

--
Minë Corma hostië të ilyë ar mordossë nutië të
Mornórëo Nóressë yassë i Fuini caitar.
Un thoron arart’a s’un hith mal’kemen ioke.
Saurulmaiel

 

[Daniella68313]

not kick much for birds in flight.

Were you overly optimistic after the fix? Even with the Tamron TC
1.4x? I wonder why not for birds. Maybe the size of the bird from
far away relative to size of sensor?

I think lack of contrast, distance and speed. the ai focus seems to loose track of an object if it move out of focus too fast.

It's a hair pulling case..so I
have stop even thinking about it. I don't want to be hairless in a
year or 2

At the rate you shoot birds, under a year maybe....but you've
stopped thinking about it.

I can trigger it easily though if I trigger it on close recomposing
of close-by objects, but then it takes some time to spot the bird
and focus on it again. By that time, most likely there is no more
bird to focus on.

I have started relying only on single focusing at the time of the
shot.

This is what I use mostly. Before I bought the 300D I recall
reading threads on why some 10D users weren't crazy about AI Focus.

unless you're firing the shutter

right away as soon as you get an AF lock (which I seem to recall
reading). Myself, I've had iffy results when the AI-Servo kicks in
(maybe better with the Sigma than the 75-300 IS).

--

--
Minë Corma hostië të ilyë ar mordossë nutië të
Mornórëo Nóressë yassë i Fuini caitar.
Un thoron arart’a s’un hith mal’kemen ioke.
Saurulmaiel

--
http://www.pbase.com/golfpic/digital_rebel_2
http://www.pbase.com/golfpic/the_adventure_of_squirrels
http://www.pbase.com/golfpic/cabot_trail__cape_breton

--
Minë Corma hostië të ilyë ar mordossë nutië të
Mornórëo Nóressë yassë i Fuini caitar.
Un thoron arart’a s’un hith mal’kemen ioke.
Saurulmaiel

 

[Daniella68313]

then you must add on your own reaction time. the time between your brain recognise the beep and the time your finger fully press..that may not seems like a lot but it can be.

I'm talking about the focus lock beep, so we are talking about the
same thing, i don't wait for a focus lock beep, i just push the
button, i have the picture fairly well infocus from prefocusing and
then start pushing the button as i've stated before, so it's either
miss focus or shutter lag, i'm thinking shutter lag, so what is the
shutter lag time on the rebel?

On my 300D, if I have prefocused with half press, then from the
time I full press the shutter release until the shot is taken is
about 120 ms.

If I do a full press to begin with, I don't know what the time is
from the beep until the shutter is fired. I had never been thinking
about focus implications of shutter release delay.

I assume AI servo can't help us here, as doubtless it stops
tracking once the shot is committed by the full press (since, for
example, the mirrors and diaphragm start to move then).

Best regards,

Doug

--
Minë Corma hostië të ilyë ar mordossë nutië të
Mornórëo Nóressë yassë i Fuini caitar.
Un thoron arart’a s’un hith mal’kemen ioke.
Saurulmaiel

 

[Daniella68313]

with the 300d, "theoricaly" you can focus on some objects, get a focus lock and if that object move out of focus, the ai servo will then kick in and follow it. In practice it is a little different.

Simon

else you will see shutter lag between when you half depress the
shutter button and AF locks, and when you fully depress it and the
shutter (after lag) fires.

Servo mode has predictive focusing that will continue to focus baed
on the motion during this lag period.

oh really?

I have to try this.

--
Minë Corma hostië të ilyë ar mordossë nutië të
Mornórëo Nóressë yassë i Fuini caitar.
Un thoron arart’a s’un hith mal’kemen ioke.
Saurulmaiel