Next suggestion....Cycle through all various focus modes in the menu...like Continuos servo and go through a ll the different focus points, 9, 21, 51, 51 Auto. And on Single servo, move the focus point around and see if it has a problem with all the points., Then try manual focus and see if the dot comes on when in focus. Also, does the AF button initiate focus better than the shutter release half way down?

Usually, I have found it is some unusual setting I have somehow put the camera into, rather than a disfunction in the camera. And, you did clean the contacts in the camera lens mount with electrical contact cleaning fluid and a Q-tip, correct?

How many clicks on the D700?

Have you tried locking it to release only when focused? That will a/ identify when it is struggling to focus and b/ stop unsharp images. Does the AF assist light help?

There are situations when just about all of the current cameras fail to focus - maybe you have to understand and come to terms with that - I just focus near the spot I was on and recompose. It should not stop you shooting, just delay release for a second or two while you focus and recompose.

adamz, just tried cleaning the contacts and still having the issue.

Ironheart, yes I tried the "green dot" reset with no luck as well and just had the battery out for a while cleaning the contacts.

I created a video of what it's doing. There are times it is much more hesitant to find the focus. It will just sit there and toggle like it does towards the end of the video and not lock on at all.

Here is the link to the video: http://youtu.be/hVBeBfL9HSI

Did you do a factory reset? Also, try pulling the battery for a few minutes.

use a contact cleaner to clean the contacts on the body

So I tested, tested and tested some more. I'm lead to believe now that it's not so much a back focusing issue as it is an autofocus issue.

There seems to be a problem causing the camera/lens to hunt for focus in certain situations. I'll hit the shutter release (or AF-ON) and I can hear the lens trying to grab focus and the autofocus indicator in the view finder will toggle quick back and forth (>...<) and then lock with both arrows illuminated (><) then suddenly it will grab focus (display the in focus dot) and snap the picture. And it most cases this leads to a blurry photo. I noticed this occurring when trying to take a photo in low light and well lit conditions.

Any advice on what could be causing this?

To answer sprayandpray and adamz, definitely haven't hit the camera or knocked it into anything.

msmoto, that was actually the first thing I checked and all is good on that front.

+1 sprayandpray - any chances You hit Your camera?

Back focusing would suggest the lens itself is closer to the film plane...not really possible unless something moves. Or, some other factor... I would check to make certain the AF Fine Tune is not somehow enabled, and that it is not adjusted to something other than zero.

Are all your lenses the same? Any chance it has been dropped or thumped against something?

The past two shoots I have done I notice that my D700 was having issues grabbing focus. I did some test shots just now and noticed the focus point was not on. I did a focus chart test and found it is now having severe back focusing issues that definitely were not present before.

Is there any reason as to why this could be happening? I tried a second lens and it's doing the same thing.