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Old Jul 5, 2008, 10:54 AM   #1
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This is just a quick snap, but is somewhat representative of a problem on a few other pics. The girl came across as unsharp and slightly out of focus, but the other objects appear fine. I believe that they were at basically the same distance from the camera.

Any idea what causes this?
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Old Jul 5, 2008, 11:12 AM   #2
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Hmmmm, Why didn't the picture post??

Ah HA! Too big.

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Old Jul 5, 2008, 1:20 PM   #3
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To me it looks like the camera focused on the piano. The person on the left is a little fuzzy too. But the girl being closer is more out of focus. You might try a smaller aperture.

Just my 2 cents worth.
Tim
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Old Jul 5, 2008, 9:12 PM   #4
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i agree with zippy, it focused on the piano, what you probably did was take the shot with the center focus point, thats fine if you do this, but you will have to focus on either person,(hold the shutter half way and listen for the beep) then adjust for composition, the press all the way on the shutter! good luck, john!
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Old Jul 6, 2008, 6:10 AM   #5
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Thanks for the replies. I am a spaz and thought something was up with the camera. I guess I have new gadget paranoia.

I was using the 3 area autofocus and it looks like all three areas missed the foreground, so I have switched to center, which I am more used to.


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Old Jul 6, 2008, 6:58 AM   #6
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1/2 push button to focus on what you want to be infocus, then still holding button 1/2 way in reframe your shot and then full press shutter, it will also make sure that subject is properly exposed too

gary
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Old Jul 6, 2008, 2:55 PM   #7
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I think it has to do with depth of field.

at the point where you focus the following happens:

- about 1/3 in front of the focus point (between you and the subject onto which you focus)... is sharp...

- 2/3 of the depth of field is behind your focus point.

Depth of field (DOF) = the area that is sharp..outside this area the things become unsharper the further away from the DOF.



X X

CAmera ---------------------> X X

X X

X X

Between the X is the DOF. This area becomes larger as you use a larger F number.

With a low F number your DOF is smaller.

DOF depends also on focal length....there is a website that explains it too:

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

I think she is just outside your DOF.

DOF can also be endless! then it starts at your focus point and extens endlessly towards as far as you can see....look at your lens...there is an endless sign on your lens somewhere...



OR.....your shuttertime was not fast enough to compensate for her head movement...but you remained still..so you are sharp...

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Old Jul 6, 2008, 10:44 PM   #8
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Another thing that could be problematic is that the aperture you were using was too wide for the focal length and camera-subject distance chosen, which will decrease the depth of field dramatically. IOW, for that particular shot, instead of 55mm at f/5.6, you could try a little wider(35mm instead of 55mm)at f/8 or f/11. At that range, the flash would still have done a good job, and by focussing on the subject(s), the shot would probably have been OK. At close distances, with flash, I always use at least f/8, more for sharpness than anything else. One last "rule"- for any given focal length, the depth of field increases as you move away from the subject and decreases as you move toward the subject. Good luck Robert
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Old Jul 7, 2008, 5:01 AM   #9
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Wow. That is a lot of info, thanks to everyone.

Feetjai,
Great website, after years of p&s with compact cameras, I did not realize how little DOF I had to work with.
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Old Jul 7, 2008, 3:48 PM   #10
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feetjai wrote:
Quote:
I think it has to do with depth of field.

at the point where you focus the following happens:

- about 1/3 in front of the focus point (between you and the subject onto which you focus)... is sharp...

- 2/3 of the depth of field is behind your focus point.

Depth of field (DOF) = the area that is sharp..outside this area the things become unsharper the further away from the DOF.



X X

CAmera ---------------------> X X

X X

X X

Between the X is the DOF. This area becomes larger as you use a larger F number.

With a low F number your DOF is smaller.

DOF depends also on focal length....there is a website that explains it too:

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

I think she is just outside your DOF.

DOF can also be endless! then it starts at your focus point and extens endlessly towards as far as you can see....look at your lens...there is an endless sign on your lens somewhere...



OR.....your shuttertime was not fast enough to compensate for her head movement...but you remained still..so you are sharp...

Correction as you have noticed:

1/3 2/3

Y X X

CAmera -----------------------Y--->O X

Y XX

Y X X

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