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AI Servo, AF point selection question for close moving objects

ilzho
Rising Star

Hello:

 

I just came back from the horse race track and looking through some of the photos, the camera/lens (of course not the photographer 🙂 ) couldn't get the horses in sharp focus when they were bunched together racing by.

 

I have a Rebel XSI (2008) and the manual stated to keep the automatic AF point selection (all 9 points) when shooting in AI servo.

 

I would like to know your thoughts?

 

I tried the center only AF point and it worked good as long as I kept it on the horse as it raced by 🙂 even in bunches.

 

Thanks,

David

 

 

16 REPLIES 16

If it was easy everyone could do it & no one would really care about a better than average photo. As for that nice long lens you'll need to get a big bank account to move up to one of those. Work on your technique & think about just what you'll need in gear as you do that. 

"A skill is developed through constant practice with a passion to improve, not bought."

Yes, that's way out of my price range and honestly I don't need anything like that.

I'm a beginner, learning the dslr, functions, etc.....

Going out and doing and trying is fun and frustrating... It's trial and error.

My attempt with motion blur. ISO 200, f/7.6 1/60

IMG_6588.jpg


@ilzho wrote:

Yes, that's way out of my price range and honestly I don't need anything like that.

I'm a beginner, learning the dslr, functions, etc.....

Going out and doing and trying is fun and frustrating... It's trial and error.

My attempt with motion blur. ISO 200, f/7.6 1/60

IMG_6588.jpg



Nice shots.  I think you could take even better shots with a tripod, especially on panning shots like the one above.  The IS circuitry in the lens will reward you for it.  You will really be able to freeze the riders in sharp focus.

 

What type of head to use is a personal preference thing.  I have ball heads, and pan/tilt heads.  I mostly use "video" tripods, which means I'm using gear with a 100mm bowl, or a flat mounting plate, instead of a center column.  I haven't settled on what type of head I like the most.  I can switch from one type of head to another by swapping ball adapters, or mounting plates.

 

Like lenses, each type of tripod head shines in specific scenarios.  Ball heads are fast, quick and easy to re-adjust to a new target in various directions.  Pan/tilt heads are slower to adjust, but great for when your shots will mostly be along a constant horizontal plane, like panning on horses as they run by.  Better ball heads have horizontal panning controls.  With either type of head, a well leveled tripod is a must.

 

Horizontal panning on a tripod minimizes up/down camera shake.  In fact, Canon's professional grade, telephoto lenses have Image Stabilization modes that are optimized for horizontal panning, and will actually ignore side-to-side camera shake because you're panning.

 

Once again, nice shots.  You seem to be using shutter speed creatively, and most effectively I might add.  Follow the advice about  using just the center point.  Don't let the camera choose what to focus on.  I mgiht also add that pre-focusing [one shot mode] on a specific distance, area, or zone, and waiting for subjects to enter it works well for me. 

 

[EDIT]  For a shot like the one above, I would use Back Button Focus to lock focus on the ground where the horses will run across.  Once focus is locked, I can press the shutter without the camera re-focusing.  With enough depth of field and continuous shooting mode, you just might be able to get capture some great shots of the whole herd of riders in focus, instead of just the one.

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"The right mouse button is your friend."

Thanks so much for the comments/advice. I appreciate it.

As far as a tripod is concerned, my brother gave me one, but the horse race track will NOT allow tripods at all 😞 nor lens over 15". Except for the official track photograhers which one is below.

 

Yeah, I'm still kicking myself for not using the center AF point. I guess that's one way to learn 🙂

 

I need to learn/look up the back button focus.

Here's another motion blur photo.

 

.IMG_6551.jpg

IMG_6592.jpg

Back Button Auto Focus.

 

http://learn.usa.canon.com/resources/articles/2011/backbutton_af_article.shtml

 

I have found BBF useful.  I'm not good at holding the shutter halfway down, and moving the camera at the same time.

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A 15 inch lens is pretty long.  I hope that doesn't include the hood.  If you're using a 100mm lens, then a 70-200mm might be the most that you need.  From what I have seen so far, your 100mm seems to be doing a pretty good job of covering it.

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"The right mouse button is your friend."

Awesome.

I never tried it. I'm already in the creative mode (TV & AV) shooting, so now I will figure out how to custom that function. 

I will practice on the cars passing by in may area and see what I can get.

Thanks.

By the way here is the tripod my brother told me I can borrow. Too bad I can't take it to the track.

FullSizeRender (54).jpg

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