Unexplicable (to me) focussing problem wuth D7000

The other day I took a couple of pics from runners with my D7000. Auto focus on AF A and 1/400. Although the green focusindicator was on, the picturs are out of focus. Viewing in ViewNX2 shows the focalpoints are spot on the body or the face. So I must do something wrong. Any help would be appreciated.

Cheers,

Ted

Hi,

For moving targets try AF-C and put the Area Mode on S - use the single focus mode like you would for a stationary object and the D7000 will track it. Try that and see if you have better results - I use it, successfully, with similar situations. Good luck!

Daf

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http://www.dafshots.com

For moving subject, use AF-C. AF-A mode is much slower begining to track subjects. Also check if your focus is set to Release priority or focus priority. By default I think it is set to realease, which means the camera will fire even if focus is not achieved. Set it to Focus priority. Also use dynamic area because it works much better for moving subjects.

The AF areas are larger than you might think, so in all probability you've simply ended up with an AF area that's partly covering the area behind the subject you want. It's a very common focus issue for all of us.

In these situations it's useful to focus on a static spot on the ground, give yourself some extra depth of field by using a narrower aperture and shooting when the subject gets to area you have covered ( prefocus in other words ).

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StephenG

That is what I do for moving subjects too, AFC and dynamic.

In fact, I rarely take the camera out of AFC anyway, though if the trigger finger is heavy, one may need to switch back to single shot.

The other thing is, I try to lock on the subject before pressing the trigger, to allow the camera time to lock and focus track. Then press. Dunno, seems to work for me.

I use the D5000.

Here are a couple...









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.....Just from an amateur......'Sometimes it's to your advantage for people to think you're crazy.”

To clarify, something that was not correct per se...I use AFC together with 'continuous' shot, and shoot either single or multiple as needed, hence my reference to trigger finger and if one needs to switch to single shot.

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.....Just from an amateur......'Sometimes it's to your advantage for people to think you're crazy.”

For a situation like this where you know exactly where your subject is going to be, trap focus can be a useful technique.

http://www.digital-photo-secrets.com/tip/1303/how-to-use-trap-focus-to-get-better-sports-and-wildlife-shots/

Thanks for your help. I've set a1 and a2 to fous. Which area mode to D9, D21, D31 or even3D? Do you think Is 1/400 to slow for a runner?

Tedhouder said:

Thanks for your help. I've set a1 and a2 to fous. Which area mode to D9, D21, D31 or even3D? Do you think Is 1/400 to slow for a runner?

Click to expand...

AF-C and AF-Area mode "9pt" will work well here. Be sure that your a3 menu is set to "off" AF-Area mode "3d" might also but only for this particular shot and you need to practice with it to get consistent results. I stay in release priority but that is a personal pref. My "percentage" of in-focus shots may go down but the "total number" of in-focus shots goes up.

Here are some great settings you might works with

http://forums.dpreview.com/forums/read.asp?forum=1034&message=37815130

When you next upload a pic for help.... upload a jpeg directly as it comes from the camera to your gallery here (no cropping or PP in another program)

Then go here http://www.dpreview.com/members/settings/profile

And under the "Privacy and Safety" tab check "Allow" under "allow download of original" That way we can download the pic to ViewNX2 and check the camera settings you used. That assumes you uploaded pics/files as they came from the camera vs any change in Photoshop or the like. It will give us much more info to work with and help us better help you. Good Luck and Happy Shooting

Thank you all for your help and advice.

Cheers,

Ted

it picks random things to focus on. Take control. Or get a P&S.

I've used 1/320 on a walking peacock and gotten blurry feet. I didn't think the bird was moving that fast at walking speed, but apparently its feet were.

I hate to mention it, but it appears your camera is backfocusing a bit too. Mine did much the same out of the store where I bought a new lens. The large traffic sign I shot had more stuff in the background in focus than the sign itself which was maybe 1/5th the frame and centered. Once home and more testing, it turned out it needed something on the order of -30 AF tuning to correct it which it couldn't do. Off to Nikon the new lens went (body had already been addressed and worked with other lenses) and it came back perfect at zero now.

Mack

His shot was 1/125. Yours was 1/400.

The tips from you all has been a great help. Thanks. The only thing that still puzzels me is the fact that the picture in my OP is clearly out of focus, but when I check it in ViewNX2 the red square is right there where I wanted it to be. Any explanations?

The camera thought that it had focus. It didn't.

There is a small lag between when the camera computes focus and when the shot is actually fired. AF-A introduces more lag than AF-C (and probably even more than AF-S) as the camera is computing. With predictive AF, the camera will use the rate of motion of the subject to compute where it thinks the subject will be in those milliseconds later when the actual shutter opens.

Sometimes the camera gets it wrong. Sometimes (like this time) our settings choices make it easier for the camera to get it wrong.

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Catallaxy

Tedhouder said:

The tips from you all has been a great help. Thanks. The only thing that still puzzels me is the fact that the picture in my OP is clearly out of focus, but when I check it in ViewNX2 the red square is right there where I wanted it to be. Any explanations?

Click to expand...

Catallaxy gave a good explanation. I would add that the red box in viewNX2 is only an indication of what AF-Sensor was primary when the shot was taken. As an example, in AF-S and AF-Area mode "single" with the center focus box selected....point the camera at your foot and half press the shutter release button until you get a green light and focus locks. Now raise the camera and point it at the runner while the shutter release button is still half pressed. Fully press the shutter release now with the runner in the distance. Review the photo in ViewNX2 and the red box will be on the runner while we know you focused on your foot. The same problem can happen when your a3 menu is set to a long interval in AF-C.

My second shot there, admittedly not one of my sharpest, is at 1/125.

However, to be safe, a slightly higher shutter sppeed would be better, say 1/250.

1/250 can stop a lot, unless the lens is really long (telephoto).

So, at 1/400 or 1/500 it should stop running action easily.

Maybe birds, with their fast wing rate and long tele required, may require faster, ask one of the birders here.

Cheers
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.....Just from an amateur......'Sometimes it's to your advantage for people to think you're crazy.”

This is a very common issue with the D7000.

By the same token all people here have given great explanations!

so nothing to add I guess.

Thanks to all the clear explanations given by all the posters the issue is solved now. I've changed the settings according to the advices given here and will certainly try AF-ON. I tried it at home yesterday and it seems to result in faster focussing. I will certainly try it in action. Thanks again.

Cheers

Ted

Avoid using AF-A mode and use AF-C instead.
Here are the AF settings I have found to work best for the D7000.

Set AF mode to AF-C
a1 AF-C priority set to Focus (this is very important!).
a3 Set to OFF.
a6 Number of focus points = 39
f5 Assign AEL/AFL button to AF lock only.

I choose the number of AF points base on the requirements of my subject.

1 or 9 points for static objects.

9 points for slow or predictable direction moving subjects.

21 points for erratic moving subjects (like hummingbirds), that only fill a small portion of the scene.

With this AF set-up, keep your shutter button half pressed so the lens continuously adjusts focus until you actually fully depress the shutter. Focus and re-compose is accomplished by pushing and holding down the AFL button after subject focus is achieved.

I have had excellent results (90%+), using the above AF settings and can see what the camera is focusing on before the shot. I can't say that about AF-A mode, which is hit and miss due to a lag time shifting to continuous servo mode when sensing movement. The concept behind AF-A is a good one, but AF-A gets confused too easily so the implementation is just too unreliable in my experience to want to use it. Personally I feel that Nikon should remove the AF-A option, if they can't get it to work more reliably than it does currently.

Best regards,
Jon