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Photography Question 
Leeandrea Benton
BetterPhoto Member Since: 8/30/2006
 

Yet another focus question


 
  Not sharp
Not sharp
© Leeandrea Benton
Nikon D80 Digital ...
 
  Smaller aperture, still not in focus
Smaller aperture, still not in focus
© Leeandrea Benton
Nikon D80 Digital ...
 
  In focus (very close to subject)
In focus (very close to subject)
© Leeandrea Benton
Nikon D80 Digital ...
 
 
Help please!

I have a Nikon D80 and I feel pretty stupid for upgrading from a D50 because I thought the D80 would create sharper images. My problem is that my image are only sharp if I am right upon the subject. I've read about this in other threads and the answer tends to be to shoot with a smaller aperture to have more of your picture in focus. But I've done that and it still it seems like NONE of my subject is in focus even though I always make sure the subject's eye(s) are in the focus box. I've tried increase the ambient light (2 150 watt light bulbs) in my studio but that only helped a small bit.

I just took someone's senior portraits and can't use any of the full length shots (in fear that they'll look crappy when blown up).

At first I thought it had to do with my equipment but now I'm beginning to suspect that it's just me! Any suggestion?


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2/10/2008 8:15:28 PM

 
Leeandrea Benton
BetterPhoto Member Since: 8/30/2006
 
 
  Not in focus-face
Not in focus-face
© Leeandrea Benton
Nikon D80 Digital ...
 
 
You can't tell the first one is out of focus so I cropped the face:


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2/10/2008 8:32:24 PM

 
Pete H
BetterPhoto Member Since: 8/9/2005
  Hello Leeandrea,

First off; lighting has nothing to do with how sharp your images are. Critical focus can be attained if a scene is dark or light. Noise may creep in with dark areas, but this is not a focus issue.

2nd; what f/stop did you shoot this and what focal length? The latter being more important.

3rd: Going from a 6MP camera to a 10MP camera will not be "that" much sharper. Basic sensor math here. The D-80 does indeed have a richer feature set, but quality will not be noticeably higher than your D-50.

Finally, some lenses suffer what is known as a "back focus" problem. It is somewhat rare, but does exist. Testing will reveal if this is your problem.

Again, what f/stop and what focal length?

If I had to venture a guess based on the limited information you provided, I'd have to say your camera was focused on something else, NOT your subjects face. There are several possibilities here; incorrect auto focus setting (i.e dynamic), focus point not centered etc...


all the best,

Pete


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2/10/2008 8:58:20 PM

 
Leeandrea Benton
BetterPhoto Member Since: 8/30/2006
  Sorry, I thought the meta data would show up. It was shot at f9, 24mm. The group portrait is at f11

I thought light had a LOT to do in helping the camera's AF. I know if I had a good eye I could focus in low light manually but I'd rather not focus manually.

I thought since the D80 had more focus sensors that would help. Guess not.

My AF setting is always on Single Area.

The thing is that I consistently have the same problem when I'm not right upon the subject. I wish I could find an area in the picture that WAS in focus then I'd know for sure it was the camera but usually everything is just not that sharp. I also have a 70-300mm lens and 50mm lens. I have the same problem with these lenses, hence my frustration.

I'm wondering if its just a NIKON thing.


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2/10/2008 10:25:25 PM

 
Pete H
BetterPhoto Member Since: 8/9/2005
  No, it's not a Nikon thing. :)

Sure; it there is not enough light, the camera will have a difficult time focusing, but your D-80 should be giving you a focus confirmation with a "beep" and/or a light in the view finder when focus is locked.

Your f/stop and focal lenth info tells me this is not a depth of field problem.

Sooooo; the camera WAS focusing on something other than your subject.

More focus areas are primarily for "dynamic" focuse when you are tracking moving subjects.

Setting at (single area AF) is perfectly acceptable in your shooting of portraits.

While in "single area AF", are you sure you have the focus point selected for the (center)?..and NOT one of the outer areas?
There is a (lock) switch below the navigation wheel of your camera. Is it "locked" and is the sensor lighting up in the middle of the view finder when you focus? If not locked, it is easy to touch the navigation wheel and MOVE the focus point.
The fact that this seems to happen only when you are further away from your subject and not close up, leads me to think this is the problem.

If this is not the problem, you will have to do some tests. Focus on houses, an apple etc and check your results.

"Back Focus" does not seem to be the problem since you say it happens with all your lenses.


Pete


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2/11/2008 5:33:23 AM

 
Leeandrea Benton
BetterPhoto Member Since: 8/30/2006
  Actually, Pete, I DO always use the outer sensors when I take pictures from that distance. I guess since the subject's eyes would'nt be in the center of the frame from that distance. I never gave a second thought to the outer sensors being weaker than the center. I will definitely try that. I bet that's that my problem! (I'll let you know)
Thanks!


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2/11/2008 12:07:34 PM

 
Leeandrea Benton
BetterPhoto Member Since: 8/30/2006
 
 
  70mm
70mm
Auto-using flash.
© Leeandrea Benton
Nikon D80 Digital ...
 
  50mm
50mm
Auto-using flash.
© Leeandrea Benton
Nikon D80 Digital ...
 
  40mm
40mm
Auto-using flash.
© Leeandrea Benton
Nikon D80 Digital ...
 
  31mm
31mm
Auto-using flash.
© Leeandrea Benton
Nikon D80 Digital ...
 
  18mm
18mm
Auto-using flash.
© Leeandrea Benton
Nikon D80 Digital ...
 
 
OK, I ended up doing a little test. I took these pictures in the same spot, using the center AF sensor, with various focal lengths. There is a VERY noticeable difference in clarity the shorter the length. I was about 5 feet from the subject the whole time. I don't know what to do to fix this.


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2/11/2008 2:41:23 PM

 
William Schuette
BetterPhoto Member Since: 9/8/2006
  Hi Leeandreea, if I understand correctly, you are shooting at different focal lengths from different distances. At the shorter focal lemgths you may be at or beyond the lens' minimum focusing distance ay 5 feet. Check the info on your lens and see what its minimum focusing distance is.

Bill


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2/19/2008 8:23:20 PM

 
Leeandrea Benton
BetterPhoto Member Since: 8/30/2006
  Hi Bill, I was shooting at different focal lengths but from the same distance of 5 feet. I just used the same zoom/crop on those pics to show the difference in quality.
My problem is that it won't focus if I'm far away like 4 or 5 feet. I'm always higher than the minimum focus distance when I have this problem, though...


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2/19/2008 8:47:07 PM

 
William Schuette
BetterPhoto Member Since: 9/8/2006
  What focus mode are you using?


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2/20/2008 4:04:28 AM

 
Leeandrea Benton
BetterPhoto Member Since: 8/30/2006
  Single area and Servo


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2/20/2008 4:11:53 AM

 
William Schuette
BetterPhoto Member Since: 9/8/2006
  Leeandrea, the only additional things I can think of before taking the camera to someone to have it checked out is 1) does it do the same thing with all lenses? If not, it is probably a lens issue, and 2) On Nikon DSLRs you can generally move the autofocus control from the shutter release to the AF-On button using your menus. This is something I do on all of my cameras because it allows me to prefocus by pressing the AF-On button with my thumb and then recompose without worrying that the camera will refocus when I press the shutter release. You may want to try this to see whether your focusing issues are caused by the camera locking on to slightly different spots.

Bill


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2/21/2008 3:36:28 AM

 
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