focus for portraits

[SXW]

When taking portraits of people whereby there are say 2 or 3 in the pic, where shld my focus point be so that all 3 will be in focus. Usually when I take pics of say 2 individuals, i uusally focus on say one persons face. that person is usually in-focus, while the other maybe in focus but more often then not is not. Is there a technique so that I can get both subjects in focus?

Thanks

 

[markfftang]

Make sure you have appropriate settings to give you enought DoF for all the critical parts of the subjects, then focus about 1/3 of the way into where you want the range of focus to be as a very rough rule of thumb.

DoF will depend upon your focal length, aperture and distance to subject obviously.

 

[mike703]

To increase the depth of field (which is what you want) you need to use a narrower aperture, say f/8 instead of f/4. That will mean a longer shutter speed, which may in turn require a higher ISO setting to avoid camera shake. Have a look at the on-line depth of field calculator here to see the effects of changing the lens aperture on depth of field.

http://www.dofmaster.com/dofjs.html

--
Mike

 

[SXW]

Make sure you have appropriate settings to give you enought DoF for
all the critical parts of the subjects, then focus about 1/3

meaning if i wanted their faces to be in focus, i wld need to focus on the chest of the middle person?

of the

way into where you want the range of focus to be as a very rough rule
of thumb.
DoF will depend upon your focal length, aperture and distance to
subject obviously.

 

[markfftang]

If that's the right distance. For example, a slightly contrived situation to make the maths easy ... with your chosen settings giving you enough depth of field say 3m, with the first person around 2.5m away and the last around 4.5m away, focussing at around 3m would render all in focus from 2 to 5m.

 

[OldClicker]

--

What you want in focus is the eyes of the person closest through the eyes of the person furthest from you. You need to have the aperture (smaller opening (larger f-stop number)= greater depth), focal length (a 50mm lens has a greater depth of field than a 100mm lens) and distance (the further you are from the point you focus on= greater depth) set to get the depth of focus to do this. Then pick a focus point that is 1/3 of the way between the closest person's eyes and the furthest person's eyes. All these distances are front-to-back and assume that the people are closely bunched. – TF

 

[Uday Addala]

I'm not hijacking this thread!!

I too am in the same boat as OP. What I want to do is: get similar results as compared to a point & shoot. I know that the sensor size matters between P&S and DSLR.

And, what I'm doing to get almost similar results is: stopping down the lens to about f8 or f11 and reduce the focal length and shoot raw/jpeg fine. I'm then cropping the ones that I want the most.

I'd be interested to know what others are doing?

--
What you want in focus is the eyes of the person closest through the
eyes of the person furthest from you. You need to have the aperture
(smaller opening (larger f-stop number)= greater depth), focal length
(a 50mm lens has a greater depth of field than a 100mm lens) and
distance (the further you are from the point you focus on= greater
depth) set to get the depth of focus to do this. Then pick a focus
point that is 1/3 of the way between the closest person's eyes and
the furthest person's eyes. All these distances are front-to-back
and assume that the people are closely bunched. – TF

 

[SXW]

--
What you want in focus is the eyes of the person closest through the
eyes of the person furthest from you. You need to have the aperture
(smaller opening (larger f-stop number)= greater depth), focal length
(a 50mm lens has a greater depth of field than a 100mm lens) and
distance (the further you are from the point you focus on= greater
depth) set to get the depth of focus to do this. Then pick a focus
point that is 1/3 of the way between the closest person's eyes and
the furthest person's eyes. All these distances are front-to-back
and assume that the people are closely bunched.

What happens when all 3 subjects are at the same distance, that is, they are standing next to each other side by side?

– TF

 

[markfftang]

Just make sure you have enough DoF in case they move forward or backward a bit and focus on the eyes of the one you estimate is 1/3 of the way back to front.

 

[AdriaanMeijer]

What happens when all 3 subjects are at the same distance, that is,
they are standing next to each other side by side?

That's quite easy, they are the same distance to the camera, so in theory one person in focus means all three are in focus.

--
All in my humble opionion of course!

(I might get a preposition wrong -or any other word for that matter-. English is a nice language, but it's not mine)

 

[OldClicker]

What happens when all 3 subjects are at the same distance, that is,
they are standing next to each other side by side?

--

Everything above still applies. Make sure you have the depth of view required to get the whole body and focus on the eyes of the one in the middle.

Remember that the focus is not really at an equal distance (that would be an arc/circle) but in a plane that is parallel to the sensor in the camera and goes through the point of focus on the subject.

TF