I had a combination of canon 40D + 70-200 F2.8L IS shooting kids activities mostly with that such as swimming events or corss country run and some time soccor game etc. I have seem so many great shot posted on this forum and eager to get some tips from you experts on techniques regarding tracking moving object effectively Using AI servo mode. I am using camera defaul setting under Av mode most of the time. Evaluate meetering and continues drive and AWB. I often ended up with blurring subject (camera ended up focused on something else). Could someone provide me some help on either How to set up the camera for this shooting situation and / or the technique for better tracking of the main subjects.
Thank you in advance. Hope one day in the future, I can come up with something that would be good enough to share with you here.
My first suggestion would be to use center point AF only. This way you decide what your subject is - not your camera. You just have to concentrate on keeping that center point on your subject!
Thank Randy. I will take note of that and try it. So I will Use Center Focus Point only under AI-servo. Mean while, for example, if I am trying to capture some shots by tracking my son ruuning, where should I place that focous point at? His face or shoulder or other parts of the body so I can catch his whole body as well as having a relatively good focus on his face? I tried to put the face in the center area before and often end up having to corp the image for it to look right at the end.
I use the same technique that a boxing coach one told me. Watch or aim for the mid section the head can not be far off. Does the 40D support * focus. If so you might try using that as well. It's custom function 4 third setting on the 30D.
Sometimes its hard enough keeping the focus point on the body. Trying to keep it on the face/head will likely result in more OOF shots. Keep it on the body. That should get you in the ball park. Note that black or low contrast uniforms make any auto-focusing more difficult since the system is based on contrast.
When you've "mastered" that (if a person ever can), then concentrate on targeting faces/heads.
I'll be more basic. Is it motion blur or just focused elsewhere?
You say that you are using the 40D defaults with AV. Not sure what you mean by that. You still have to set the ISO (or are you using Auto-ISO) and the aperature.
So presuming you are shooting between f2.8 and f4.0 in AV - what ISO are you using? and what shutter speed are you getting? If your shutter is dropping below 1/500th, you are going to be quite prone to motion blur. If it drops down around 1/300th, you can add camera shake to the equation.
Center point focus is a good start, but if you want the face in focus and the action is fairly close (and thus your depth of field (DOF) very shallow), you will need the focus point on the face. If you use center point that means you will have a very loose frame. So until you are able to master the tracking, if you want faces in focus you will need to consider increasing your depth of field by using a smaller aperature - i.e. 4.0 instead of 2.8.
Thanks for all the comments. Sorry I did not make myself clear enough in the earlier message:
To shoot moving objects (like kids running around, sports etc), I would use Av mode and set an f stop so I can get a relatively high shutter speed, say 1/500 or faster. I will to choose as low as a ISO I can get to achive the shutter speed.
I have not try to use the center point only for tracking, that is something I will definately try first. Also in ealier message, what is * focus? I do not quite get it. I say a AF-ON button on the 40D, but do not really know what is the advantage and how to make good use of it yet.
The non-keeper I got often resulted from focusing on undesired part or things in the frame or just OOF all together. Much worse than simple motion blur caused by the slow shutter speed.
The * focus means that you change a custom function (# 4), in your camera's menu so that the * button on the back of the camera is what triggers the auto focus, and is operated by your thumb. Most people shooting sports use this technique. One advantage is that you can engage the focus independent of the metering/exposure process.
The camera's default is that a half-press of the shutter button triggers the autofocus mechanism along with the camera's metering. Then, a full press, of course, triggers the shutter.
I wouldn't worry about the * focusing right now though. Just concentrate on following action, using the center point, getting exposures in the ball park, and shooting lots of pics.
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Alright here goes my spill on shutter/ae lock on my 30D to get * focus which is useful for objects that are moving and stopping. I go to custom function 4 and set to #3 AE/AF, no AE lock. Body must be set in AI servo for this to work. Then you use your thumb to focus rather than the pre trigger half actuation of the shutter button. It really incresed my number of keepers try it you might like it. Might I add it also caused me to want a 1D.
Just to confirm what I read, I have to keep holding down the * button during tracking as well as the shutter half way (for AE) while tracking and shooting a miving subject, correct? So while you press the shuttle to shoot, as long as the thumb is still pressing the * or AF-ON, my center focus point is still trying to focusing on the subject, that sounds right?
If you are using the * button there shouldn't be a need to also have the shutter down half-way. It's * to focus and keep focusing (yes hold it down unless you want to stop the AI from changing the focus) then shutter down completely to take frames when you want to take frames. I bet a search of the forums would yield quite a lot of reading to do on this technique.
As someone else mentioned you may want to work up to this technique too as it can take some getting used to.
Are you leaving the IS turned on or off. If on, then you will need to have the shutter button press half way for the IS to operate. If you do not need the IS, then turn it off. I understand that you could have a slight len shake if the IS is turned on at the same moment the picture is taken.
That is a good point. I almost never turn off the IS, and leave it on Mode 1 almost all the time. Now when shooting sports / kids / or tracking other moving tagets, do people use IS? My impression is IS would still be a plus rather than a minus. Also, besides putting it on a tripod, under what other circumstances that it is better to trun the IS off?
For the most part IS is used when you go below an acceptable shutter speed (usually the equivalent to the lens length, for eg, less than 1/200 for a 200mm lens). Unless you have terrible hand shake or poor technique that is the only situation when IS really helps. Otherwise, hand-holding at higher shutter speeds should not require the use of IS. When trying to capture motion,then, such as with sports, you'd ideally like to catch them at shutter speeds higher than that anyway, negating, in essence, the need for IS. IS could be useful for some smooth panning at slow shutter speeds with objects in a constant direction, but then you might want to consider mode 2 for that. Otherwise, with sports the action is often so unpredictable and quick that IS really isn't worth it.
mcarlson wrote:
For the most part IS is used when you go below an acceptable shutter speed (usually the equivalent to the lens length, for eg, less than 1/200 for a 200mm lens). Unless you have terrible hand shake or poor technique that is the only situation when IS really helps. Otherwise, hand-holding at higher shutter speeds should not require the use of IS. When trying to capture motion,then, such as with sports, you'd ideally like to catch them at shutter speeds higher than that anyway, negating, in essence, the need for IS. IS could be useful for some smooth panning at slow shutter speeds with objects in a constant direction, but then you might want to consider mode 2 for that. Otherwise, with sports the action is often so unpredictable and quick that IS really isn't worth it....Show more →
Thanks for the comment. I will try to have the IS turn off next time to see If I can see any difference.
