Back focus issues.. Camera(D7000) or Lens(70-200 VR1)?

[TheLost]

Over the past few weeks I've started noticing more and more 'back focused' images... before everybody starts screaming "Its the D7000!" let me say that I've had this camera for over two years and this problem only popped up a few weeks ago.

I haven't changed anything in my shooting style or settings... but i'm getting more and more images like this..

This isn't the best image but it shows my problem (raw image w/no pp.. shot @ f/3.5 1/2000sec and ~180mm). The focus point was placed on the kid in the gold jersey yet the kid in the background is more in focus. The compressed DOF makes it hard to tell but the kid in the background is about 2 feet behind from the kid in the foreground. For this picture i actually set my camera to 'focus priority' to make sure it had focus lock before the picture was taken.

I've gone back over the 1000's of pictures I've taken this year and its defiantly something new

I'm trying to decide if i should send my Lens in to get looked at... or possibly both my camera and lens. I'm cheap and trying to keep Nikon from taking all my money.

Any ideas?

 

[Ballistics]

I'm having the same issues now and it seems to be out of no where. I'm having a hard time focusing with my Sigma 70-200mm

 

[SCraig]

Put your lens on another body and see if the problem persists. If it does it's probably the lens. If not, put a known good lens on your body and see if it persists. If it does it's probably the body.

You could also adjust your body for the back-focusing issue. There is a menu option to do that.

 

[JaronRH]

What AF mode are you using? I've seen cases where the AF jumps from one subject to another when in Continuous focussing mode with 3D tracking while trying to track the subject (since the AF module isn't as smart as you an I ). Can you reproduce the problem when using the center point and a static subject? If so, the D7000 should let you adjust the AF if needed (temporary fix) but you might want to send your body and lens in for calibration.

 

[TheLost]

What AF mode are you using? I've seen cases where the AF jumps from one subject to another when in Continuous focussing mode with 3D tracking while trying to track the subject (since the AF module isn't as smart as you an I ). Can you reproduce the problem when using the center point and a static subject? If so, the D7000 should let you adjust the AF if needed (temporary fix) but you might want to send your body and lens in for calibration.

I use D21 (21-point dynamic-are AF) mode... I've shot tons of games in that mode with no problem until recently. I may try 9-point or single point this weekend.

I've done some highly scientific tests: Flower pot sitting on a yard stick in the back yard... backing up ~30 feet.. taking a picture @ f/2.8... focus is dead on.

Anybody know how much a lens calibration normally runs?

 

[JaronRH]

What AF mode are you using? I've seen cases where the AF jumps from one subject to another when in Continuous focussing mode with 3D tracking while trying to track the subject (since the AF module isn't as smart as you an I ). Can you reproduce the problem when using the center point and a static subject? If so, the D7000 should let you adjust the AF if needed (temporary fix) but you might want to send your body and lens in for calibration.

I use D21 (21-point dynamic-are AF) mode... I've shot tons of games in that mode with no problem until recently. I may try 9-point or single point this weekend.

I've done some highly scientific tests: Flower pot sitting on a yard stick in the back yard... backing up ~30 feet.. taking a picture @ f/2.8... focus is dead on.

Anybody know how much a lens calibration normally runs?

Try this test out before jumping far a calibration: Jeffrey Friedl's Blog » Jeffrey’s Autofocus Test Chart When I was looking for a 70-200, I first tried the Sigma lens and it had pronounced back-focus. I used this test (camera on a tripod, multiple lenses, the whole 9 yards) and could confirm that the issue was with the lens itself and not a user or camera AF error. I ended up returning the Sigma (for the NIkon 70-200VRII) but Sigma did offer to calibrate it for me for free (I think most companies do if it is under warranty still).

 

[TheLost]

Update...

I printed out the cart linked to above.. glued it to a piece of MDF and started testing.

On both my Nikon 50mm 1.8 and Nikon 70-200 f/2.8 there is some back-focusing going on. The selected target in the chart IS IN FOCUS but its not the center of the focal plane. It looks more like this...

5
4
3
2
1
0 <-- focus target
1
2

Changing the Micro Focus adjustment didn't seem to make much change. (On a side note... DAMN is the Nikon 70-200 sharp @ f/2.8!!)

I then went out and bought a lens calibration program i read about (FocusTune) and gave it a try. I was expecting it to tell me to set my micro adjustment to -20 on my 70-200mm, but surprisingly it said -17 was sharper!


Sooo.. after shooting my last football game of the season this weekend and still seeing tons of out of focus shots (that should be in focus).. i think its my camera

Anybody know how long Nikon takes to look at a camera? I've got basketball season starting in a few weeks...

 

[Derrel]

I think the 21-point AF option is too many points...

I have better luck with the 9-point option enabled. In my experience, 21-point AF is often too many points!!!

I've shot sports before, but not with a D7000...but still, that football shot...the kid on the left...the kid on the right...EITHER ONE could be construed to be "the target" if the AF area in use is very large or wide....

Are you HAND-selecting the AF area with the 4-way controller to begin the sequence? Or are you totally,totally allowing the camera to select the "target"? The traditional,advanced method is to use the 4-way to "tell the AF module" what the target IS, and then the RGB color metering will follow that target ,even if it moves across the frame...so...

AF in modern Nikon bodies is very complicated...there is more than one way to skin a cat...not saying the problem is "you"...but,uh...the problem might be your exact working methods and control settings...

 

[TheLost]

I think the 21-point AF option is too many points...

I have better luck with the 9-point option enabled. In my experience, 21-point AF is often too many points!!!

I've shot sports before, but not with a D7000...but still, that football shot...the kid on the left...the kid on the right...EITHER ONE could be construed to be "the target" if the AF area in use is very large or wide....

Are you HAND-selecting the AF area with the 4-way controller to begin the sequence? Or are you totally,totally allowing the camera to select the "target"? The traditional,advanced method is to use the 4-way to "tell the AF module" what the target IS, and then the RGB color metering will follow that target ,even if it moves across the frame...so...

AF in modern Nikon bodies is very complicated...there is more than one way to skin a cat...not saying the problem is "you"...but,uh...the problem might be your exact working methods and control settings...

I will be the first to admit the problem could be me

I switched over to 21-point after i started noticing a problem about a month ago.. The way i understand that it works (and i could be wrong) is that the camera uses the active selection point (for me, that's the center point 98% of the time). When the shutter is pressed (or half pressed) the other points kick in and watch for the target to move. I'm not ruling out its something i'm doing wrong... I think i'm still going to get my camera checked out just in case.