Focusing settings & techniques: Guidance required re: Single point

[Pegasus_Thrust]

Hi All,

Once again I am sure this has been asked before but it's a bit of a needle in a haystack trying to find the answer amongst previous posts- so apologies if this is going over old ground.

I always used to use a 51 point auto area setting on my D3 and more lately my D800E but now in an attempt to improve hit rate etc. when required I switch to selected points. But at a wedding the other week I consciously went to single point to capture the stationary bride and groom but as I did I began to think whether this was the best option considering I had 2 faces/sets of eyes I wanted in equal focus and only 1 focus point to work with.

My questions therefore are: is single point the best for this scenario?..... if so, what should I train the focus on?- do I pick a mid point and slightly risk less sharpness either side or pick one and risk the other being slightly out (the thinking being maybe having the bride pin-sharp)

I guess within that all I am seeking to know how single focus works and what sort of loss of focus is suffered outside that single point- is it just that area behind that single red square that will be A1 or if a subject next to is at pretty much the same distance from the lens will that be pretty much be as good?
.....or do I go for 9 point focusing? I remember at the wedding being quite close in and my thoughts were if I want the eyes/face sharp my hit rate would be affected if I went down the 9 point avenue (I ideally don't want to be doing too many clicks at that point of a wedding too)

Any help or guidance would be massively appreciated.

 

[johnnypanic]

What is in, or out of focus, will be influenced by your aperture and focal distance.
The single point, will allow you to focus on a small specific area, e.g. bride's eye, which will mean anything on that focal plane will also be in focus.
If you use a very narrow focus, e.g. 2.8, it would be very difficult to get acceptable focus on a couple. Therefore you may wish to use a less shallow depth of field, e.g. 5.6, etc.

Also, f stop and depth of field can also be an artistic decision. In that, you may wish the eyes to be tack sharp and the rest of focus "fall off" quickly.

 

[Pegasus_Thrust]

Cheers John, I had considered the f-stop aspect. But 9 times out of 10 I do rely on shooting at 2.8 because of low light and because a lot of vicars I come across don't allow flash during the ceremony..... and as you say I do like the effect wide open gives.

So in theory would you say try being less wide e.g. 5.6 and single point focus?...... on the thinking if one set of eyes is in focus the other might be?

Aside from the technical aspect I also began to ask myself the question in certain shots "is the bride the real subject and the absolute priority rather than the groom anyway?" and therefore it's single point on her all the way.

 

[Phil V]

You've made the question complicated, because you're thinking about the gear not the photography.

The simple answer; only the plane of focus will be in focus. Anything in front of or beyond it will be out of focus. How much out of focus will depend on your aperture and the distance from the camera.

Whether you use a single focus point or 51, only a single plane will be in focus, there's no way that the camera can give you multiple planes of focus.

 

[Pegasus_Thrust]

Thanks Phil, how would you tackle it in which case?

 

[Phil V]

Thanks Phil, how would you tackle it in which case?

Same as always, closest eye of the subject. If you have a couple and they're far enough apart to not both be in focus, choose your subject. Sometimes it's the bride, sometimes the groom, sometimes the MoB etc. You choose the image to support the story you're telling.

 

[Terrywoodenpic]

I only ever use a single point to focus, for as phil v says there is only one plane of focus, and I like to make my own decisions about where to put that plane.
nevertheless I do choose which focus point to use, as the centre one is not always appropriate.

Modern cameras use algorithms to try and guess what a skilled photographer would choose in a given situation.
It is very far from an exact science but will certainly work near enough, sometimes.
Nothing is as accurate as knowing what you want to achieve and having the skill to do it.... this involves thinking about every shot...
and thought takes both time and planning.
When all is said and done, focussing accuracy requires a choice to be made and takes as much time as is necessary.
Automation is much quicker and makes exceptionally fast wrong choices almost every time.

Choosing a focus point is quite different to predictive follow focus which can be automated exceptionally well.

 

[Pegasus_Thrust]

Thank you both. I shall continue with my single point with a higher f-stop and Phil the choosing the closest eye of the subject seems to make a lot of sense.

 

[johnnypanic]

Remember also, if you're shooting at 2.8 to ensure adequate shutter speed and not thru artistic choice, increase your iso. Better to have a grainy, well focused image than a blurry one.