Focussing issues. Help needed

scottduffy · 13 Sep 2009

Hi Guys, I am using a Canon 450D and a Sigma 105 Macro for mostly portrait stuff and have been really pleased with the results when it is a single person. Group shots or couples are proving more troublesome though. I use mostly P mode and when i select the centre point for focus it obviously focusses on the person the point is on. When i leave the camera on auto focus points it usually selects the person nearest the camera. I have wasted a fair amount of shots due to them not being focussed properly. Should i just increase the f stop to f11 or so or should i be doing someting else? Any advice greatly appreciated. Sorry if this is a stupid question to ask.

PerfectSpeed · 13 Sep 2009

If your outside in solid shade with good light and a couple

Set to M
SS 1/250
ISO 100
f/8

That should get some results to start you off.

scottduffy · 13 Sep 2009

Thanks. I'll give that a go soon.

coldpenguin · 13 Sep 2009

What about A-Dep? (not that I have used it that successfully)
In theory, it modifies the aperture, shutter speed in order to maintain a depth of field which covers all the subjects that the focal points fall on?

donut · 13 Sep 2009

aperture priority and f 8/11 sounds good to me ( if you have the light )

pearce_jj · 14 Sep 2009

How about getting a 50mm F1.8 or even a 3x-mm lens, standing closer and using that at F8. It would produce much more DoF.

scottduffy · 14 Sep 2009

Hi Pearce JJ,

I have a Canon 50mm f1.8 so i might give that a shot next time. I was just playing about with the Sigma because it's new.

mrtoad · 14 Sep 2009

i use P

i let the camera focus on the nearer...shoot
focus on another face...move the central sensor area..shoot
choose the better

manual focus i feel would solve it all

awp · 14 Sep 2009

Doesn't matter what aperture you use if the focus point is not on the subject! Common mistake with couples and centre focus point is the focus is on the background between the subjects! Smaller apertures will not compensate for an error like that. Choose a different focus point to suit the subject. On the D3 I use 51 point 3d tracking. Check your camera manual to see what options you have.