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Archive 2012 · Why do you focus off-center?

erosebud
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p.1 #1 · Why do you focus off-center?

I'm not very creative, and my photos show it: pretty flowers, majestic mountains, noble bighorns, glorious sunsets. I do have some feel for the rule of thirds and the like, but on the whole I just take pictures in order to capture a thing of beauty. That may explain why I don't understand--particularly in regard to much of the discussion of the 5DII--what matters so much about using a non-center AF point. It seems to me that it would take more physical movement to accomplish it, for one thing (moving the multi-stick to shift the point and then hitting whichever focus button you use, as opposed to focusing, holding it, and shifting the camera a bit--though I grant that this would be more work on a tripod).

Not trying to start a fight, but to learn something. Can you tell me how you work this way and what advantages it holds for you? Thanks.

Jan 06, 2012 at 02:50 PM

jasonpatrick
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p.1 #2 · Why do you focus off-center?

I use a different point when I'm shooting vertically...if you're trying to focus on a person's eyes, their head is usually going to be in the top 1/3rd of the frame. So you use a different point to capture more of their body and less above their head. For flower shots, you can usually crop (if you have the pixels) the photo to be the way you want it in post. Sometimes for wider shots, you want to focus on something in the foreground that's not on center, so you could use it that way...or you could focus and then recompose. On my 50d, changing points is a fairly simple process and can be done without moving your eye from the viewfinder.

That being said, I use the center point 90% of the time. YMMV

Jan 06, 2012 at 02:58 PM

leftymgp
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p.1 #3 · Why do you focus off-center?

First of all, I'll say that I'm in the same boat as you. I like cameras and taking pictures but I have very little artistic talent and most of my pictures would be considered pretty boring.

Anyway, with the 5d series, I think there's an argument for using the center point as the center AF point is better than the others. Something about it being a cross type point and being able to recognize vertical and horizontal planes... I'm not exactly sure.

But one might ask why one would use the other points. I think the first one is that typically your focus could be a little off if you use the center point and then move the camera. Ideally the other points are as good and when you use them your focus will be most accurate. The second would be exposure, but if you lock the exposure before you recompose then that's not really an issue.

Not sure if I've ever heard people harp on not using the center AF point before. Also, with the 5d2, you have so much cropping ability that it's almost not necessary using anything but the center AF a lot of times.

But anyway, hopefully somebody who knows what they're talking about will come along and really answer your question.

Jan 06, 2012 at 03:04 PM

outlawyer
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p.1 #4 · Why do you focus off-center?

leftymgp wrote:
First of all, I'll say that I'm in the same boat as you. I like cameras and taking pictures but I have very little artistic talent and most of my pictures would be considered pretty boring.

.

My pictures are going to be published as a sleep aid. Ambien will be rendered obsolete. Guaranteed to have you snoring in under 3 mins.

Jan 06, 2012 at 03:15 PM

joakim
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p.1 #5 · Why do you focus off-center?

When using a fast lens wide open it is more critical to get the focus right so if you're subject is not in the middle of the frame using an outer focus point is more accurate than using the middle one and then recomposing.

From a creative point of view an image gets less static if the main subject is not in the middle of the frame, same logic as the rule of third.

Jan 06, 2012 at 03:24 PM

jj_glos
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p.1 #6 · Why do you focus off-center?

As already said, I use off centre a lot when taking shots of my daughter. It is very rare that I want the focus point (normally her eyes) in the centre of the frame. Like this for example:

This image is copyrighted by the owner

Christmas 2011 by jj_glos, on Flickr

Generally with sports I'll use the centre point, but again I'll use off centre if I need to. Like this:

This image is copyrighted by the owner

Prescott Speed Hill Climb - Autumn Classic 2011 by jj_glos, on Flickr

I use off centre far more than I use just the centre point. That's why I went the 1Ds2 route not the 5D2.

Jan 06, 2012 at 03:29 PM

Eric Gottesman
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p.1 #7 · Why do you focus off-center?

Focus/recompose is also slower if you are trying to track a subject and you want the focal point off center. There's a good chance you will miss an action shot that way.

As mentioned above, focus/recompose with wide open apertures can lead to focus error, especially why you are closer to the subject or the focal point is far from center.

-

Jan 06, 2012 at 03:33 PM

Snopchenko
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p.1 #8 · Why do you focus off-center?

I like to compose AND focus at the same time and the spot I want to focus on usually isn't in the center. Guess I don't have enough attention span to focus & recompose all the time. That and with some lenses it's not practical anyways (ultrawide for example). Difficult to explain, I know, and it may be just my imagination.

Jan 06, 2012 at 03:34 PM

jj_glos
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p.1 #9 · Why do you focus off-center?

Snopchenko wrote:
I like to compose AND focus at the same time and the spot I want to focus on usually isn't in the center. Guess I don't have enough attention span to focus & recompose all the time. That and with some lenses it's not practical anyways (ultrawide for example). Difficult to explain, I know, and it may be just my imagination.

This is what I do basically, but didn't really explain. The vast majority of my subjects are in motion so focus recompose is not an option. I also don't want to crop into a full frame image as I don't want to lose the DoF look I was going for, and I don't have the time to crop\aspect ratio check every image.

Jan 06, 2012 at 03:40 PM

artsupreme
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p.1 #10 · Why do you focus off-center?

Always off center....unless you are using a 5D of course, then you have no choice.

Jan 06, 2012 at 03:42 PM

misternikko
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p.1 #11 · Why do you focus off-center?

^

!!! i HATE my 5D AF.

Jan 06, 2012 at 03:56 PM

Photon
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p.1 #12 · Why do you focus off-center?

Just to amplify what Ilya Snopchenko and jj_glos have said:
With wide aperture lenses, and with any aperture when magnification is high (think long telephoto at relatively close range) the depth of field can be a finger width or less. If the subject is moving at all, you can't get away with focus-recompose techniques. Also, the swaying of your own body can move the focused object in and out of the zone if you are not braced and you don't fire immediately upon achieving focus. That's the reason that many of us (especially shaky folks like me) use continuous AF even for static subjects if we are hand-holding something like an 85/1.2. The constant adjustments for slight movement result in a high hit rate for focus. Off center placement of focus then obviously requires an off center AF point. Some with great visual acuity manage this with manual focus!

Jan 06, 2012 at 04:03 PM

Sven Sewitz
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p.1 #13 · Why do you focus off-center?

jj_glos wrote:
As already said, I use off centre a lot when taking shots of my daughter. It is very rare that I want the focus point (normally her eyes) in the centre of the frame. Like this for example:

I use off centre far more than I use just the centre point. That's why I went the 1Ds2 route not the 5D2.

I use the off center points a lot for exactly the same reason as jj_glos: I take many pictures of my kids, and when you use a shallow depth of field, you have to have the focus point on the eyes. Often my children are running or looking somewhere. Or playing with something cute. So their eyes will not be the center of the image. Very rarely so, actually.

I am also staying away from the 5D for this reason (haven't gotten round to buying a 1Ds2 yet - but will soon be..!)

Jan 06, 2012 at 04:08 PM

robinlee
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p.1 #14 · Why do you focus off-center?

I use off centre focus quite a bit if I am using 1.4 or 2.0 aperture and they are pretty accurate

Jan 06, 2012 at 04:10 PM

Mitchell Carter
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p.1 #15 · Why do you focus off-center?

Photon wrote:
Also, the swaying of your own body can move the focused object in and out of the zone if you are not braced and you don't fire immediately upon achieving focus. That's the reason that many of us (especially shaky folks like me) use continuous AF even for static subjects if we are hand-holding something like an 85/1.2.

Exactly what I do, and why. (It was either that, or give up coffee)

Jan 06, 2012 at 04:26 PM

Stoffer
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p.1 #16 · Why do you focus off-center?

Sven Sewitz wrote:
I use the off center points a lot for exactly the same reason as jj_glos: I take many pictures of my kids, and when you use a shallow depth of field, you have to have the focus point on the eyes. Often my children are running or looking somewhere. Or playing with something cute. So their eyes will not be the center of the image. Very rarely so, actually.

This.

And my 7D doesn't really has enough focus points to accomplish the goal of keeping focus when they move around. Tried a Mark IV for a week, and lets just say that I'm going 1-series one way or another this year.

Jan 06, 2012 at 08:35 PM

erosebud
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p.1 #17 · Why do you focus off-center?

Thanks, friends! I grasp the logic many of you have presented and appreciate the thoughtfulness of everyone who responded. I'm going to be developing a new skill, I think.

Jan 06, 2012 at 08:39 PM

obroni
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p.1 #18 · Why do you focus off-center?

It is simple. It happens (quite often) that I want to focus on a spot that is off center of the frame. In case I know the outside focus points will handle it, I use them. If not, I use the center point and recompose before taking the picture.

Jan 06, 2012 at 08:47 PM

mttran
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p.1 #19 · Why do you focus off-center?

misternikko wrote:
^

!!! i HATE my 5D AF.
but it's definitely one of the best IQ when you nailed it

Jan 06, 2012 at 11:59 PM

mttran
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p.1 #20 · Why do you focus off-center?

jj_glos wrote:

This image is copyrighted by the owner

Christmas 2011 by jj_glos, on Flickr

Love to see your daughter shots, post more of hers

Jan 07, 2012 at 12:04 AM

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