D700 Difficulties - advice please

[DennisT]

Hope some-one can help.
Have a D700 with 200-400 lens (also 1.4x converter.)
Set to continuous, use mainly f 7 on aperture priority but cant get autofocus to settle. Hunts all the time - will take the shot without focus locking and some in the burst are focused and others less so..
Is there something I don't understand or is this gear faulty?
PS. Am a relatively new convert to Nikon and this is my first Nikon kit.

[volks]

Nikon states that with that lens auto focus is not possible at "some" focal lengths when using the 1.4 teleconverter.

[wfooshee]

When maximum aperture gets smaller than f:5.6, autofocus gets difficult. You have to have enough light for the sensors to see what's out there. So whatever the lens's aperture is, add a stop for the converter. f:4 becomes f:5.6, f:5.6 becomes f:8, etc. You can't autofocus at f:8.

The setting for your aperture priority has nothing to do with that, unless you're shooting stopped down for some reason. It's the maximum aperture your lens is capable of that is the issue.

[Franglais]

On Continuous autofocus it will do just that - the system is constantly evaluating the results from the autofocus sensors and trying to pick the best one. Now if the subject is moving slightly or if you are moving the camera slightly then it will try to follow.

In AF-C mode the camera will shoot any time you press the shutter release, whether it has focus or not. The assumption is that the subject is moving and the autofocus may not be always spot on but it's better to let it shoot than have no picture altogether.

You may be making things worse by activating too many focussing points. You have the choice between 9, 21 and 51. 51 focussing points gives you better coverage of a subject that's roaming all over the field (example: tennis player) but the system will react more quickly if it only has 9 points to evaluate (which are also the most sensitive).

Be aware that the system just adores focussing on objects with lots of high contrast detail like fabric and is less keen about diffuse things like skin.

Your 200-400 with 1.4x teleconverter has a maximum aperture of f5.6 which is the darkest the system is supposed to support. If focussing is critical a f2.8 constant lens would be better.

BTW what are you shooting and why aren't use using AF-S? It sounds like you are expecting the thing to behave like it does in AF-S mode.

[DennisT]

Thank you for the responses. I use the rig for bird and wild life only and it is true that there are occasions when the contrast at the subject could confuse the autofocus. Following your advice I have taken it out again to double check myself. However, when switched to S mode the hunting continues!!!
I have stopped using the 1.4x converter as it has become apparent that the communication between lens and camera becomes compromised - think the whole thing is too heavy for the mount - so much so that some pictures in the same burst are badly over exposed and others are black (in the exif the black shots are recorded at F0?). Sometimes the viewfinder shows the F symbol paired with a right angled triangle which the manual explains indicates a non cpu lens attached and this is clearly not the case in this instance (this happens also when the converter is not attached and the lens is attached directly to the camera). So, guys, I think I have a problem.

[Franglais]

How about a D7100 (when it becomes available). 24Mpix and no need for a teleconverter with the crop sensor..

[volks]

Is your 200-400 a Nikon lens ?, and how old is it ?
You may want to try that lens on someone elses Nikon camera. That should tell you if it is your lens or the camera.

[frankc]

Hi I'm trying to help my father out who has a D7000. I don't know much about photography.

He has a message or information displayed on the LCD screen which he doesn't know how to remove. He can still take photographs but when the picture is taken the message is transposed over the photograph.

The message or information appears in a black rectangular transparent field and says

Noise Reduc :Hi ISO NORM
ACT. D-LIGHT :AUTO
RETOUCH :

COMMENT:

Is there a fault on the camera or has he inadvertently altered some sort of setting. He has tried resetting the camera and taking the battery out but it still appears.
Any idea how to remove it?

[wfooshee]

To frankc:

The data being displayed is not part of the picture, but overlayed on it by the camera for use by the photographer. You can select several screens of that data by using the up or down sections of the cursor pad while viewing an image. You can turn it off by goting to the menu, find the Playback menu, then Display mode. In the Display Mode menu, move up or down to highlight boxes that are checked, hit OK to uncheck them, and then highlight Done at the top and hit OK again. (The Data box is the one that specifically adds what you describe.) You can then exit the menus and the extra display will be gone.

[frankc]

Many thanks wfooshee it's much appreciated. I'll let him know. He said he's tried everything to get it off and can't find it in the manual but we'll do this,
regards
Mick

[wfooshee]

"Display Mode" p. 197.

[DennisT]

Ok get this - had occasion to travel to to Cape Town last week so took the entire rig to Nikon - they found that the bayonet fittings required replacement, did so and solved the problem.
Lesson learned - do not stow the rig with camera, lens and converter all attached. The weight on the bayonet fittings cannot be accommodated without severe wear, bending and/or distortion.
I had always kept the gear fully assembled in a Lowepro back pack but will now invest in a hard case.
Thanks to everyone for responding to my post and for all the advice.
Dennis

[wfooshee]

Didn't think about that, and I'll bet a lot of folks don't.

I bag my camera with the 18-55 kit lens on it, but if I had more space, dividers, whatever, I'd bag it and the lens separately, as the 18-55 is one of my least-used lenses other than family events. I've never even considered toting the camera bagged with heavier stuff on it, but not for weight. It's a space consideration.