Single Point vs. Zone AF Question

[DonnaCPhoto]

I know when shooting one subject, single point AF is the best setting to get optimal focus, but what about shooting more than one subject (a couple for instance) or a group of people - should I be using zone AF?

 

[Mtalicarox]

That's what I normally do.. but I'd be interested in hearing the answer to this as well...

 

[jamesdavidboro]

I asked a similar question about a week back. Heres the thread :-
http://www.thephotoforum.com/forum/...rum-photo-gallery/224951-auto-focus-area.html

 

[DonnaCPhoto]

James - yes i read that one, but I'm still not clear.. 2 people mentioned to use single point for portraits.. but for example - if I am shooting an engagement or wedding portraits with 2 people in the shot, then should I be using zone focus instead? Otherwise, if I position the focus point on one person, the other will be out of focus? Maybe I should be upping my F-stop on single focus? I still want to achieve good bokeh though.

Still confused...

 

[jamesdavidboro]

You can't focus on more than one distance at a time. You can only focus on one distance then it comes down to your dof as to weather subjects infront or behind that point are in focus. As Big Mike said in that thread "When you get more than one focus point to light up, it means that both those points are over something that is the same distance away from the camera"

 

[kundalini]

Your focal plane will be approximately 1/3 in front of your focal point and 2/3 behind. If you're wanting to get two people in focus, then it makes sense to have them closer on the same plane. Stopping down your lense to ~f/8 will probably be your lens's sharpest apeture, but in the same breath, will likely not produce the bokeh you're after.

Having the ability to 'achieve good bokeh' is dependant on several factors. First is the lens's capability. 9 rounded apeture blades will produce a much better bokek than, say, a 5 bladed not-so-rounded apeture blade. This generally is closely related to the cost of the lens, not always, but it's a good rule of thumb. But more over, it is the distances between camera to subject combined with subject to background. This is where practice and test shots becomes oh so pertinent.

For reference on depth of field..... DoF Calculator.

 

[table1349]

Start here grasshopper Camera Exposure: Aperture, ISO & Shutter Speed. (Kung Fu - tv show in the 70's) As you follow your journey through metering and DOF all will become clear.

Master Po: Close your eyes. What do you hear?
Young Caine: I hear the water, I hear the birds.
Po: Do you hear your own heartbeat?
Caine: No.
Po: Do you hear the grasshopper which is at your feet?
Caine: Old man, how is it that you hear these things?
Po: Young man, how is it that you do not?http://en.wikipedia.org/wiki/Kung_Fu_(TV_series)#cite_note-3
​

 

[DonnaCPhoto]

Gryphons - Fantastic article - thank you!