how do you focus?

[thekid17]

one shot?

ai focus?

ai servo?

[Riaan van Wyk]

Focus for what subject? You need to be much more specific.

[thekid17]

deer coyotes that are moving or still

[Riaan van Wyk]

ai focus, camera wil refocus as soon as subject starts moving.

[BradM]

AI servo is really the only way to go, you can use it as if it were one shot if situations warrant but for wildlife or birds something is always moving or even breathing and the focus can change missing that critical point needed for a great image.

AI focus will not take into account minor movements and if shooting long glass at close distances, and often wide apertures, mean that minor movement is a soft or oof eye in the shot.

[Tom Reichner]

deer coyotes that are moving or still

Well, which one - moving or still?

I use AI servo for all moving subjects, and I prefer to use One Shot for all subjects that are entirely still.

If a subject is standing in one place, but turning his head, then I use AI servo, as a subject that is turning it's head is not still.

If the eyeball is still, then I consider the subject to be still, and will switch from AI to One Shot if I have the extra second it takes to make the adjustment.

Why do I prefer One Shot for still subjects? Because it allows me to lock focus, then compose the image exactly the way I want to. When I have the image composed precisely the way I want it, the odds of the subject's eyeball being exactly on a focus point are very, very unlikely.

If I'm using AI and compose the image exactly the way I want it, then the focus will not be on the eyeball. It may be close, but if that little red box is not on the eye, it's probably going to be a wasted image.
And if I'm using AI and I keep the little red box exactly on the eyeball, then odds are that the image will not be composed precisely the way I want it to be composed. I really hate to crop even a little bit to get the composition I want. I want absolutely perfect composition right in the camera, the moment I press the shutter button.

[canonnoob]

ai focus, camera wil refocus as soon as subject starts moving.


nooooo BADDD.. Stick to one shot or AI servo only.

[kampers]

That may help with my bird pictures. I have been shooting with one shot setting.


AI servo is really the only way to go, you can use it as if it were one shot if situations warrant but for wildlife or birds something is always moving or even breathing and the focus can change missing that critical point needed for a great image.

AI focus will not take into account minor movements and if shooting long glass at close distances, and often wide apertures, mean that minor movement is a soft or oof eye in the shot.

[Daryl-Hunter]

I use aI servo all the time, I don't need one shot as I use a custom function control on my eos to shift focusing to a button on the back of the camera I control with my right thumb.

[rdricks]

AI Servo, focus on the back button

[EL_PIC]

I use AI servo for all moving subjects, and I prefer to use One Shot for all subjects that are entirely still.

And ... I often use "Double Clutch" methods on front button.
In other words ... Lock on more than once.
Focus Twice - Click Once !!

Manual works also ...

[Overread]

AI Servo, focus on the back button

+1 though add in that you ideally need a lens with USM/HSM focusing setups

This lets me keep the constant AF feature for when/if the subject moves around, but also lets me use AI servo focusing like oneshot for when the subject is no longer moving and I want to focus and recompose. Setting the focusing button to a back button and removing it from the shutter button half depression means that one can focus (using the backbutton) - recompose the shot - lock and take the shot without the shutter button being pressed causing the focus to start hunting again.

I would also add that for higher level camera bodies you can use different AF points as well as predicting the action to ensure that you can get the focus on a moving subject (using AI focus) whilst also focusing the shot off-centre rather than always using the middle point. This works better in higher level camera bodies because of the increased quality and accuracy of the outer AF points - whilst entry level models are more limited.

[bibteewolfe]

recently been practicing manually focusing... its actually quite an art that deserves considerations for some shooting situations... im no pro at it, but i certainly am getting better with practice...

[sandpiper]

AI servo for moving subjects, one shot for stationary subjects and AI focus when pigs fly aerobatics over the frozen wastes of Hell.

[sandpiper]

ai focus, camera wil refocus as soon as subject starts moving.

That sounds good in theory, but in actuality it starts off in one shot then, if the subject starts moving it thinks about it and if the subject keeps moving it will clunk into ai servo and start to track the subject. As AI servo is predictive, it needs to track the subject for a short while to work out what it is going to do.

That all adds up to a very noticeable delay before the AI servo really kicks in, by which time you have generally missed the shot with a lot of subjects.

If you are expecting the subject to move, use AI servo straight away and get rid of the laggy response time with AI focus. AI focus is like most settings where you let the camera make the decisions - a poor second to doing it yourself.