How many of you use multiple AF points?

ajf

ajf

ajf

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Was looking around at new bodies and the likes of the 7D etc that have multiple cross type AF points.
How many of you ever use these in groups, or auto rather than just choosing one specific point?

Reason I got looking was an itch to change my 600D. It only has a central cross type AF point but I rarely manually select any other.
How reliable is a group or auto AF points really?
I am thinking motorsport or aircraft mainly.
 
I'd be interested to hear these results too. I have been using spot focus for motorsport and wildlife and multifocus for more scenic views.
 
Depends entirely on what you are shooting and the situation.

I tend to leave both my 7D and 5D on full AF points, unless I'm specifically intending to control where I want the AF to be.

Say if I was shooting a sport or an event, I may choose certain AF zones because I know that is where its going to be best framed, or I want to avoid the AF hunting an object that is partially closer to me.

With more portraiture or creative photography, you may want to use a single AF point or zone if you were using a large aperture, where if you haven't got the focus right, you miss having what you want in focus.
 
Tend to use all except for portraiture based where I pick one so I can frame around the eye as focal point. Then again, 9 points is limiting :(

kd
 
Nexus said:
I tend to leave both my 7D and 5D on full AF points, unless I'm specifically intending to control where I want the AF to be.
Click to expand...

Exactly what I do. But I'm a complete novice so no idea if I'm doing it correctly tbh. :D
 
ajf said:
Was looking around at new bodies and the likes of the 7D etc that have multiple cross type AF points.
How many of you ever use these in groups, or auto rather than just choosing one specific point?

Reason I got looking was an itch to change my 600D. It only has a central cross type AF point but I rarely manually select any other.
How reliable is a group or auto AF points really?
I am thinking motorsport or aircraft mainly.
Click to expand...


Well, you should always select the focus pout closets to your intended subject focus. The whole focus and recompose idea is best aided if possible as it can lead to focus errors due to fieldcurvature often lens.


That is why you need focus points covering a large area of the frame. The reason why you want a high density of focus points comes from being ble to do focus tracking for moving subjects- an absolute must for things like sport and BiF. Since the subject moves and changes distance you will need the camera to track the subject making adjustments to focus.
 
Skalaberg said:
I'd be interested to hear these results too. I have been using spot focus for motorsport and wildlife and multifocus for more scenic views.
Click to expand...

That seems like the wrong way round. In static scenes you have no time pressure so can manually choose the exact focus point that you want.
This is important. Because you really need to pick the focus point that maximizes your depth DoF focus and ensures the right parts of your scene are focused.

For landscape work it is good to read about hyper focal focusing and to pick a focus point that will maximizes DoF for the scene-typically a point about 1/3rd of the way in to the scene. The dynamic multi point auto knows will likely pick something too close or too far away.



For sports and wildlife you have much less time to control anything and the subject is moving so you need a dynamic focusing system to track the subject.
 
Multiple points are there to be used. Most of the time I'm using a single AF point out of the 61 available but I will use an AF zone or cross or a block depending on what I'm tracking within the frame.

Most of the time I can pan and track easily with just 1 AF point and keep the AI servo button held down (remapped DOF preview) while shooting so servo tracks at that point whilst other times it's a specific zone that I want tracked where the subject will be and no other area.

The AF system on the 5D3 is immense, took a long time to get familiar with all the zones and groups and the modes for them, still learning them.

Oh and then there's AF speed and sensitivity for any given scenario that you can customise for a shoot.
 
Thanks.
Some interesting points and comments to consider there.
I do occasionally select points but was really wondering whether more actually helped or was simply a 'selling point'.

The ideas of grouping points sounds useful though having read more in some reviews.

My idea was to maybe get a used 7D or the new 70D. Both seem to have the same AF system from what I could find?

Other reasons too for buying anyway.
 
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