July 22, 2014, 05:24:49 AM

Author Topic: Back Button Focussing and AF Points  (Read 2271 times)

JPAZ

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Re: Back Button Focussing and AF Points
« Reply #15 on: April 18, 2014, 12:41:36 PM »

Quick question: Using BBF, is the camera's AF performance still relevant? Number of AF points etc?

You can still choose zones and focus points on the fly it just separates the focusing form the shutter button.
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Re: Back Button Focussing and AF Points
« Reply #15 on: April 18, 2014, 12:41:36 PM »

climber

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Re: Back Button Focussing and AF Points
« Reply #16 on: July 09, 2014, 02:21:22 AM »
Hi.

I would like to ask something those of you, who are using back button focusing.

Do you always have set to AI Servo (also when shooting stationary subjects) or do you toggle between One Shot mode (for stationary subjects) and AI Servo (for moving subjects)?

PS: I understand that, in case you use AI Servo for everything, you probably focus stationary subjects with a single press on a back button.

Thanks

Menace

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Re: Back Button Focussing and AF Points
« Reply #17 on: July 09, 2014, 03:31:27 AM »

Quick question: Using BBF, is the camera's AF performance still relevant? Number of AF points etc?

You can still choose zones and focus points on the fly it just separates the focusing form the shutter button.

+1

I'm so used to BIF that it's pretty much 2nd nature, in fact  the first function I change on a new body is the BBF.
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Tarkkaamo

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Re: Back Button Focussing and AF Points
« Reply #18 on: July 09, 2014, 04:52:09 AM »
Do you always have set to AI Servo (also when shooting stationary subjects) or do you toggle between One Shot mode (for stationary subjects) and AI Servo (for moving subjects)?

AI Servo all the time. One Shot mode means just lifting your finger from focus button.

tdrive

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Re: Back Button Focussing and AF Points
« Reply #19 on: July 09, 2014, 06:52:33 AM »
I use BBF all the time but i find a lot of times i have let go of the back button before pressing the shutter. In essence this is much like manually focusing and then i read this article which makes me wonder whether it is interfering with the metering (usually evaluative).
I guess the moral would be to not let go of the back button until you have successfully taken the shot?

http://www.foto-biz.com/Canon/7d-limits-of-evaluative-metering

tculotta

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Re: Back Button Focussing and AF Points
« Reply #20 on: July 09, 2014, 07:06:22 AM »
Here's a quick primer on the benefits, as one person describes them, plus how to set it up (Canon and Nikon.)

http://www.naturettl.com/back-button-focus-game-changer/

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GaryJ

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Re: Back Button Focussing and AF Points
« Reply #21 on: July 09, 2014, 07:38:10 AM »
My macro is mainly rocking focus[MP-E 65] all other work,BIF,landscapes,portraits and stuff are all BBF ,after talking with a Canon service rep[hard to find in QLD Aus]I was shown the algorithms involved that convinced me of the benefits
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Re: Back Button Focussing and AF Points
« Reply #21 on: July 09, 2014, 07:38:10 AM »

mackguyver

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Re: Back Button Focussing and AF Points
« Reply #22 on: July 09, 2014, 10:12:16 AM »
It took me quite a while to be convinced to try BBF, I was very skeptical! Well now I am happily eating my words, it is much more flexible - once you get used to it!

Agreed.  I've tried the AF-OFF approach, but I don't find it as useful.

I think its usefulness depends on your general subject matter, if you regularly shoot sports, BIF and other dynamic subjects it makes much more sense and once you are used to a way of doing it it makes sense to just use that approach for everything. If you shoot less dynamic subjects and have a camera with good off center AF points then it becomes less important, indeed it is the focus recompose scenario where I want to place the focus point out to the edge of the frame that I use BBOFF most. (I just registered BBOFF as a trademark  :) )
When I had no choice (older film bodies) I was very used to the half press focus and recompose, and I was mostly shooting portraits.  When I moved into DSLRs and wildlife, that just didn't cut it for me and I tried BBF.  I've been in love with it ever since!

Now we have the best of both worlds with the new 1D X firmware.  You can set the back button AF button to AI Servo and AE lock button to One Shot, or vice versa.  You can even customize the focus points and how they are selected for each button!  As I don't use AE lock a lot, I did just this, and then moved AE lock to the custom buttons on the front.

I'm still getting used to it a bit, but for me, I use AI Servo 90% or more of the time, but will use One Shot when the light is low, subjects are still, etc.

As for shutter+AF button, it drives me insane after using BBF for so many years.  I have everything perfectly focused and then I push the shutter and wait (arghhhh!) for the focus then realize it's off after the shot fires.  The delay and potential to re-focus make me crazy.   

That's just how I feel, but I completely understand other people's feelings to the contrary :)
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pdirestajr

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Re: Back Button Focussing and AF Points
« Reply #23 on: July 09, 2014, 10:55:38 AM »
The reason I love BBF so much is that it really allows you to take advantage of full time manual focus. Otherwise, when you touch the shutter again you are fighting yourself.
It really shines with weaker AF cameras like the 5DII, as I use center point AF to grab focus, then recompose and tweak focus manually while shooting. Really increases hit rate with shallow DOF shots.
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Re: Back Button Focussing and AF Points
« Reply #23 on: July 09, 2014, 10:55:38 AM »