20D Football

[mercphoto]

I've been having trouble with youth football using my 20D and a 300/2.8. Going in Av mode at f/4, center-point only, AI-Servo focus. I usually go half-shutter to let the camera focus and track, then rattle off a few shots. Profile shots are sharp, the problem is when the runner is coming at me. Focus is soft, actually slightly behind the runner. Makes me believe the camera is not keeping up with the motion. There has to be a technique to doing this correctly.

[Nikolai]

... since I'm bound to run into the same situation...

[Ann McRae]

Hi guys
Can't talk specifics of football or the 300mm lens. However, I copied my methodology from a Canon soccer shooter named Nill Toulme. Also cannot say that I have 100% success in focusing where I want to, but my success rate improved dramatically with practice.
It is:
Manual mode, largest apeture possible to isolate the subject as much as possible. Then play with the iso and shutter to get the best exposure.

I have IS turned on although that is not supposed to make a difference. Nill's advice was 'it can't hurt', so fair enough.

And then this next one might be a left over from shooting indoor where I was having exposure issues caused by the recycling of the lights. In any case, I shoot in custom function 4, 3. This has you focusing with the star button on the back of the cam with your thumb instead of half pressing the shutter. This sets focus when you press the star and will track the moving player. Exposure is then set at the time of the shutter press. This was important in a burst series where the light recycling would wreck havoc over the series of shots. In any case, I find that using the star button for focus very easy, convenient and I think eliminates some camera shake issues.

I also always used a monopod.

HTH

ann

[PossumCorner]

Ann thanks for that advice, your work has been a real inspiration for me to diversify from my dog-sports shots. Went to my first soccer match last week, just local teams, and the last game of the season. I was really pleased with the results considering I had left the tripod in Paul's car: a monopod is now a must. And yesterday I went to the first cricket match of the season, only took a few shots under clouds and the rain started (end of game) but again was pleased with this first attempt. At both sportsgrounds the clubs were helpful and welcoming, so I think if I kept at it there would be a few sales.

And Merc thanks for the question - with head-on action shots of the dogs, I need to pre-focus on a set point they will cross, but even then the DOF isn't a given, because the dog's best action can be too early or too late to be in focus. (And they are too fast to track and focus coming straight-on).

[mercphoto]

I have IS turned on although that is not supposed to make a difference. Nill's advice was 'it can't hurt', so fair enough.
I question the "it can't hurt" advice myself. Some of Canon's image stabilization circuits go crazy when on a tri-pod, so who knows if a monopod would do the same thing.

I also always used a monopod.
And I'm having trouble adapting to that myself. Feels too limiting.

[Ann McRae]

I question the "it can't hurt" advice myself. Some of Canon's image stabilization circuits go crazy when on a tri-pod, so who knows if a monopod would do the same thing.


And I'm having trouble adapting to that myself. Feels too limiting.
Hmmm, had never heard that. I attach the body to the monopod, not the lens. Wonder if that makes a difference.

The monopod does take some getting used to, but you do get the hang of it after a while. I think I would ultimately like some kind of tilt device (there is a good thread somewhere on dgrin about that) too.

ann

[mercphoto]

Hmmm, had never heard that. I attach the body to the monopod, not the lens. Wonder if that makes a difference.

The monopod does take some getting used to, but you do get the hang of it after a while. I think I would ultimately like some kind of tilt device (there is a good thread somewhere on dgrin about that) too.
I got advice on Sports Shooter just a bit ago to not use IS on a monopod. Who knows? Who's right? Don't know.

But, I think you probably do want to attach to the lens, not the body. And with practice I probably will eventually like using the monopod. Just feels weird now. A tilt device might make it feel less confining to me. I'll do a forum search.

[Steve Cavigliano]

Bill,

I have the same problem with birds flying towards me. The ones flying parallel to the lensface track fine. But straight on, I have issues :dunno I try to track for at least a second or two and then fire, but I usually get more misses than hits :rolleyes

I've been reading articles like this (http://www.shutterfreaks.com/Tips/CanonAIServo.html) or this (http://photonotes.org/other/ai-servo.html) So far Ive been chalking it up to camera shake or lack of subject contrast. Maybe it's a combination of factors. I usually aim my focus point at the chest of a bird flying towards me. That's not exactly a high contrast area. Plus, I think that sometimes it's more difficult to keep the focus point on something coming towards you than it is to pan with it.

Good luck and let us know if you find a cure :D

Steve

[Nikolai]

From purely mathematical stand point this is rather understandable that autofocusing on the subject moving towards/away from you is a much more difficult task compared to a panning one.

I guess to resolve this issue we need a camera with "focusing bracket", but I don't even think such thing exists. The only other solution can be to close the aperture to the biggest possible value to increase the DOF and try to shoot as fast as possible once the focus is acquired.. Which brings whole other slew of undesirable side effects into the picture..

All theory, I know, but this actually *is* a theoretical problem...:dunno

[Ann McRae]

I am going to throw a couple of examples of players running toward the camera and see what you think - do these show the problem you are talking of? I am never sure if my standards are high enough.

http://canadian-ann.smugmug.com/photos/26131326-M.jpg


http://canadian-ann.smugmug.com/photos/33800853-M.jpg

http://canadian-ann.smugmug.com/photos/33800945-M.jpg


ann

[Seamus]

I've been having trouble with youth football using my 20D and a 300/2.8. Going in Av mode at f/4, center-point only, AI-Servo focus. I usually go half-shutter to let the camera focus and track, then rattle off a few shots. Profile shots are sharp, the problem is when the runner is coming at me. Focus is soft, actually slightly behind the runner. Makes me believe the camera is not keeping up with the motion. There has to be a technique to doing this correctly.
Bill, if the lens is back focusing perhaps you should get the lens and camera calibrated at a canon service centre? I read and agree with Ann about using cf 4/3 to set exposure as each shot is taken but if you can't get the player in focus you may need to get a technician to look at the combo.

Shay.

[digismile]

Hmmm, had never heard that. I attach the body to the monopod, not the lens. Wonder if that makes a difference.

The monopod does take some getting used to, but you do get the hang of it after a while. I think I would ultimately like some kind of tilt device (there is a good thread somewhere on dgrin about that) too.

annHere's the page from the Canon manual. It basically says the lens "detects" that it's on a tripod and shuts the IS off, but you are to use IS when using the monopod. This suggests to me that it detects minute amounts of movement, and that a tripod is "generally" stable enough to make the lens think it is stationary. But maybe in some rare cases, it detects some movement and kicks itself on.

This might explain why some people could have strange results on tripods.

The downside to having the IS on when using a tripod seems to be an unnecessary extra drain on the battery. Unless you're having unusual results, I would do like Ann does, leave it on.

http://digismile.smugmug.com/photos/35959133-L.jpg


Brad

[gtc]

I have found that autofocus is just not very good at dealing with moving subjects heading towards the lens- this was from shooting grey headed flying fox(megabats) at night.

The only way I found that worked for me was locking focus on a point and waiting for them to fly through it.

You could also try.....(dramatic spooky music).................... manual focus
-the eye,brain,hand combo can be surprisingly quick.

[ian408]

I shoot surf with the 1dmkii set to focus using the back button.
It takes getting used to but in the long run, I have come to appreciate
the separation of focus and exposure.

Take a look at this (http://www.outsight.com/hyperfocal.html#hyper) URL. I think you'll find your focus is really the lens DOF.

Also, if you're interested in looking at sports settings SI suggests, try
looking here (http://www.siphoto.com/) for a file you can use to set your 20d.
Settings for other cameras are there as well.

Cheers,
ian