http://www.nikonchat.com/nikkor-f-1-4g/
Problems with AF Nikkor 50mm f/1.4G AF-S?
I just bought a Nikkor 50mm f/1.4G AF-S for my D40. Together is very random as to whether the approach Machine really works or not. As long as your sun shining and I am 5m away from the goal that seams to work. But in the light varied and closer to the goal just seams to freeze and custom auto focus or take the shot. If you turn auto focus and manual focus is working very well together. Sometimes I can not try to approach automatic at all, sometimes try to confuse the focus of entry and exit and then to leave the background in focus and the lens out of focus. Surely this is not the way your work environment? So is there a problem with the lens? or is it a case of getting used to his strange idiosyncrasy?
There are many circumstances the autofocus will not work correctly. When it comes to focus for close to a subject, when trying to focus on one or very dark, etc. It has very bright object reading the manual, both the camera and the details of the lens itself. This will give you advice on what circumstances you have to use manual focus and also give you the minimum focusing distance of the lens.
Time Lapse of Winter Scene