BBF and Multi-point

craig.walton2

craig.walton2

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Craig
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I've just been playing around with BBF and I've not been overly impressed with my focus accuracy. After a bit of research I read (HERE) that its better to use mutli-point focus for shots with subjects moving towards/away from the camera. Can anyone confirm this?

This is news to me and hopefully improve my keeper rate.
 
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BBF accuracy will be exactly the same as focus on the shutter button...

Personally I don't use multi point when working in AI Servo mode unless I know the subject is large enough that all the points could get a good lock. Which is not very common... I have always found single point to give me the best accuracy.
 
Surely you need to be in charge of selecting the focus point?

i.e. manually select ONE focus point & place it where you want it, in my case right on the eye of whichever bird I'm photographing.

Enabling multiple focus points runs the risk of the camera, not you, deciding where the focus should be.
 
That's a loaded question, firstly, what Richard says is an absolute - there's no difference between how the focus behaves whether you use BBF or the shutter button.

As for how focus tracking works and the number of active points - that's very camera dependant. I wouldn't give advice without knowing the camera and lens in use, and then I'd research further - some options:

Some cameras have a multitude of custom settings to control focus, some have none, some will use adjacent points to help track focus, some won't, some focus points are extra sensitive at wide apertures, some aren't, some focus points don't even appear in the viewfinder - they exist only to help in these situations.

In light of those facts; should you use multi point :thinking:(what does multi point even mean - that in itself varies from camera to camera):help:.
 
Phil V said:
That's a loaded question, firstly, what Richard says is an absolute - there's no difference between how the focus behaves whether you use BBF or the shutter button.

As for how focus tracking works and the number of active points - that's very camera dependant. I wouldn't give advice without knowing the camera and lens in use, and then I'd research further - some options:

Some cameras have a multitude of custom settings to control focus, some have none, some will use adjacent points to help track focus, some won't, some focus points are extra sensitive at wide apertures, some aren't, some focus points don't even appear in the viewfinder - they exist only to help in these situations.

In light of those facts; should you use multi point :thinking:(what does multi point even mean - that in itself varies from camera to camera):help:.
Click to expand...
Thanks.... I think! Ok, I have a 60D. Do I need to set to 9 point when focusing on moving subjects?
 
craig.walton2 said:
Thanks.... I think! Ok, I have a 60D. Do I need to set to 9 point when focusing on moving subjects?
Click to expand...

Use center focus point, 9 point is useful when taking shots of a target with a plain background, such as a small bird in flight against a blue sky.
 
Ah. I get it now. That makes sense. Thanks
 
jm2 said:
Use center focus point, 9 point is useful when taking shots of a target with a plain background, such as a small bird in flight against a blue sky.
Click to expand...

The centre focus point on the 60d is only superior to the other points when using lenses with a max aperture of 2.8 or faster.

So the OP may* be able to choose any focus point as his single point rather than sticking to the centre one.

*He never told us what lens, so this could be wrong.;)
 
Phil V said:
The centre focus point on the 60d is only superior to the other points when using lenses with a max aperture of 2.8 or faster.

So the OP may* be able to choose any focus point as his single point rather than sticking to the centre one.

*He never told us what lens, so this could be wrong.;)
Click to expand...

*17-55mm and 70-200mm
 
Phil V said:
So the OP may* be able to choose any focus point as his single point rather than sticking to the centre one.
Click to expand...

Yes, I was using the centre point as an example, you can use the multi controller to move the single point focus from the centre.
 
If that's the 70-200 2.8 rather than f4, then centre focus point should give you better performance than the outer points. I use whichever point best suits on the 40d though - same lenses.
 
Just a thought about the function of BBF.

When I started using it many years ago it took a while to get my head used to the fact I need to maintain pressure on the button without thinking about it. In that time I know I would often drop pressure off a bit and af would become sporadic - because I was not holding the button down fully. AF would be on, then off briefly, then on again etc... and this means each time it has to re-lock.

Worth thinking about...
 
I'll keep that I mind for next time. Thanks again for the responses.
 
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