Do you half-press or use the back (*)/(AF-ON) to focus and track?

[Tin Man Lee]

Hi all, few days ago I saw from another forum that people were discussing about using the back (*) button of the Canon bodies to focus instead of half press at the shutter button. Just wondering which one you fellow bird photographers use to focus and in particular track BIF?

Link to the canon * focus:
http://www.usa.canon.com/dlc/controller?act=GetArticleAct&articleID=2286

I probably am thinking too much, but am wondering, at the short moment when you fully depress the shutter, is the focus tracking still on or do you lose that short moment of tracking? And if you fully press the back (*) then you don't lose any tracking even if you fully depress the shutter?

Thank you!

[Chris Ober]

I don't do much bird stuff but since my first EOS 5 film body I've always used the * to focus and half button press for AE Lock (CF4=1)
As long as you hold down the * it tracks.

[Mark Hardymon]

I shoot Nikon but the question remains the same no matter the brand. I have for the past two years been using the AF-On button for focus as it offers many benefits. When you acquire focus using the "back button" then release the button, focus stays locked allowing you to recompose the scene to your liking. This works best if the subject stays relatively still and doesn't move out of the plane of focus. Of course if your subject is on the move, holding the button will maintain focus and track your subject for as long as the button is held. I've had no problems with birds in flight, holding focus throughout a sequence. Using the back button method really won't affect focus since the camera "loses sight" of the subject every time the mirror pops up to make the image whether you use the back button or the shutter release button. Takes a bit to get used to but after a while become second nature. Try it and I think you'll really like it.

[Tin Man Lee]

Thanks guys! I think I will give the AF-On or * button a try this weekend. You are right about the mirror lock up. Thanks.

[Mike Tracy]

Been using it for as long as it's been available. Wouldn't consider shooting sports or any other fast paced action any other way. Small learning curve until it's second nature but after that you'll never go back.

[allanrube]

I use it too. Tin Man, it may take a while to get used to focusing that way, but it is worth it.

[Roy Churchill]

I switched to the back button (AF-ON is best for me) a couple of years ago and could never go back to using the shutter button. I shoot mostly in AI servo and a big benefit of the back button focus is that you have AI Servo, simulated one shot and manual all without changing anything.

[RichardCurtin]

I agree with the above. Have been using back button focus in Ai servo mode for most ot the past 3 years and have been very happy with the results and ease of use.

[Michael_Loizou]

Same here, cannot even think about using half-press after I tries the back button

[Cody Covey]

Same here, cannot even think about using half-press after I tries the back button
I just got my 40D today after upgrading from a Rebel XT. I had to switch it back to half shutter press because it felt so awkward to have to reach for the AF-ON button. Is there any good reason why I should just try and get used to it?

[Desmond Chan]

I had to switch it back to half shutter press because it felt so awkward to have to reach for the AF-ON button. Is there any good reason why I should just try and get used to it?

I'm sure there's good and bad with either method. I don't think there's a reason that you must use one instead of the other. As long as it gets you the results, use it. There's no law on it. Just because other people use it does not mean you have to. If you have tried it and it does not work for you, then use the other method.

I half-press. I shoot hand-held with super telephone lenses. I think it's better for me to have my thumb to help me have a stronger grip on my camera.

[peter delaney]

AF/ON.....

[Daniel Cadieux]

I switched to the back "*" focus 4-5 years ago and never looked back. Like Chris I also use the shutter button to AE Lock (useful in AV or TV modes). Felt natural from the get-go for me, but yes there could be a bit of an adaptation period for some. I love that I can have AI Servo and One Shot as one.

[John Chardine]

Agree with Daniel that using * button essentially gives you AI Servo and One Shot all in one, and you rarely need to change the focus point any more. However, there are some situations where I find it better to have the AF controlled by the shutter button only, e.g., in pure birds in flight photography, in which case I switch back to the "norm". I have trained myself to use both systems.

[Ed Cordes]

I switched a few years ago to back button AF and now love it. I keep the camera on "servo" and when the back button is pushed once and left alone I have "one shot" and have decoupled the metering from the AF. IF I hold the button down I have full servo. A learning curve is necessary and I still have an occasional brain fart from the years of "old habit" but it is still super.

[James Shadle]

I press the shutter release to activate my camera's AF system.

The reason I use the shutter release is so I never need to remove my finger from it.


Let's say I'm photographing Roseate Spoonbills and a beautiful Turkey Vulture appears.
I press the shutter release to activate and lock focus while I'm changing the exposure using thumb wheel on the back of the camera.

I almost always use AF-C aka Servo, so if I need to re-frame after auto focusing, I press the AF Lock button. This prevents the AF system from activating until released. My finger still has not left the shutter release.

[pankajratna]

Agree with Daniel that using * button essentially gives you AI Servo and One Shot all in one, and you rarely need to change the focus point any more. However, there are some situations where I find it better to have the AF controlled by the shutter button only, e.g., in pure birds in flight photography, in which case I switch back to the "norm". I have trained myself to use both systems.

I have read somewhere else as well specifically for Canon 1D MKIV that BIF is best when AF is executed by shutter button half pressed and not through back button. This summer I messed a whole series of approaching Bonelli eagle from their kill to nest with some serious soft shots. I am wondering if this could help. Does any one struggle with Canon 1D MKIV shooting head on approaching birds in flight.

Cheers

Pankaj