Single AF point tracking

Dom_Cabarete

Dom_Cabarete

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Dominic
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Hey guys, so the carribean is nice and hot and although i cant kite i can take shots:p

im having issues with keeping the subject focused when tracking him as he pops his trick, my timing is good just keeping everything sharp seems to be an issue, can anyone see what this might be or what i can do to help myself...

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Thanks
 
I get the same problem on my 40D

can't fully work out what it is, It might just be that the subject moves faster than the lens can focus (I try to do street photography, and usually end up having to "sharpen" the images later on because of this).

What focus setting do you use? i keep changing between One Shot and AI Servo, usually ends up with a good shot!
 
- I forgot to add, Love the shots, especially no. 1!:D
 
Keep the aperture quite small (no DOF problems, try f10)and crank the shutter speed up (fast as you can!) *but* you might run into the old problem of shutter lag on a Canon x0D body. That's what killed a lot of my 30D motorsport shots....
 
thanks, well im on AI Servo, i seem to be able to keep him focused as i track him but as soon as he pops for the trick it goes out even though i know exactly what hes going to do and when.... I cant help but feel like it must be my hands and i just need to learn to keep my hands steady :D
 
desantnik said:
Keep the aperture quite small (no DOF problems, try f10)and crank the shutter speed up (fast as you can!) *but* you might run into the old problem of shutter lag on a Canon x0D body. That's what killed a lot of my 30D motorsport shots....
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right right, im keeping it from around f11 and f16 its just even at 1250th at f16 its really bright even at ISO 100... Just going to keep practising i guess
 
Definitely sounds like a shutter lag problem to me....
 
is there anything i can do about it?
 
Buy a 1D body?
 
You got a pic of my tripod mount in a deckchair yet Dom? :lol::lol::lol:
Is it not possible to get a lock on prior to the stunt by keeping the shutter button pressed halfway and then click!! when the time is right?
Although I cant see much wrong with those shots. Personaly I would use more than one AF point, it looks like they are a bit of a distance.
Have a good one :D
 
desantnik said:
Buy a 1D body?
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:lol: only in my dreams at the moment :D

The tripod mount loves the sun :D, Im trying to figure out how i would do that but if i use one shot then i need to make sure i get the perfect shot, is that the only way to lock focus?
 
Seriously, few on here ever talk about shutter lag when it comes to action photography... but its a far bigger issue than you'd imagine. Somewhere on here there is a thread about it which I was asking the question... about a 30D
 
right, well i will go again today and then see what happens this time :D
 
Dom_Cabarete said:
:lol: only in my dreams at the moment :D

The tripod mount loves the sun :D, Im trying to figure out how i would do that but if i use one shot then i need to make sure i get the perfect shot, is that the only way to lock focus?
Click to expand...

Other than manual as far as I know, what I am saying is though try using more AF points if the subject is coming in from left to right, then can you not set middle and left focus points?
 
might be able to but im dont actually know
 
Well Dom here is an extract from what looks like a similar problem.

Q. Hi
Following on from a suggestion about focussing, I've been using single (centre point) focus and when I'm relatively close to the subject, this works well. However, I'm finding that when I take some action shots where things are happening quickly and the subject is some distance away from me, that the centre point is missing the action and focussing on the background. All I really have time for is to frame the photo and shoot.

For these circumstances i.e. where the subject of interest is some distance away (and hence a small part of the total photo), is there a better selection of focus points (e.g. horizontal, vertical, auto) that will enable a better overall average of "in focus" shots?

A. You can try using AI mode to follow the changing focal point. Or use manual focus. I find my AF is reasonably good though as long as the dot is on what I'm looking at and there is enough of a difference from the background for it to discern what I'm looking at. If the centre point isn't hitting on the small central target then I doubt change to any of the other 9 points will make any difference.
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I think it depends a little bit on your camera.
In AISERVO mode my 1d3 works best just using 1 of the 45 available focus points, but my 30d has a much better hit rate in AISERVO mode when I let it pick it's own focus points. Not too sure why, could be because the 30d focus points cover a smaller area of the frame, and theres only 7. Going with just one point on the 30d often has it hunting, or gaining lock only to lose it a second or two later.
If I let the 1d3 choose it's own points it often selects the wrong one and focuses on something entirely different to what I want it to focus on.... I guess it's got a 1 in 45 chance of getting it right, wherea
 
wow :lol:

great description, the wind let me down today but i'll try and let the camera choose the AF point tommorow and see how that works :)
 
this is quite interesting. I never thought of shutter lag too much of a problem with SLR's well not compare to compacts anyway. like you Dom i cant afford a 1D series body but would like to know how to get the best out of what i got if the situation presented itself
 
33L said:
this is quite interesting. I never thought of shutter lag too much of a problem with SLR's well not compare to compacts anyway. like you Dom i cant afford a 1D series body but would like to know how to get the best out of what i got if the situation presented itself
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Aaaaaaaaaaaaaagh!!!!

You mean to say I am picking up my new 50D 2morow, and its gonna have lag?
:lol::lol::lol::lol:
 
Why not try setting a reasonably small aperture, say f16, set lens focus to manual, back it off from infinity a bit, then let depth of field take care of it?
 
MisterE said:
Why not try setting a reasonably small aperture, say f16, set lens focus to manual, back it off from infinity a bit, then let depth of field take care of it?
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thats all great when you have abundant light and nothing but clear blue skies behind you, i need to shoot more wide open for subject isolation and to keep shutter speeds up without cranking the iso to silly settings.
 
Surely with abundant light you don't need to bump the ISO... certainly I find in shutter prority on a bright sunny day you end up with f11-f16 at ISO200...

And I've no idea where my post went, but I did say earlier that a 30D has a lag of 65ms, a 40/50D is 59ms and a 1D MkIII is 40ms. 40ms is 1/25th... imagine what that does if you think of the fact that AF stops before the shutter is released... then think what more than half as much again does... oh and the problem is increased with larger aperture sizes, the figures will be quoted at f22.

The results will largely depend on the nature of the action, ie how much its changing relative to the camera.
 
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