The D3400 does not work well with manual focus lenses or any AF lens with an aperture ring. If a lens has an aperture ring, the D3400 will not be able to autofocus (turn the focus ring manually and look for the green OK dot on the lower left of the finder), and it will not be able to meter or set exposure (use Manual exposure and pray). Autofocus worked fine until recently, so I had to finally read the manual. I found the A/M switch on the lens and set it to A. I believe it had been switched to M, somehow. No help. After much experimenting, I found that in viewfinder mode the lens will not autofocus, but in Live view mode, it will autofocus. So the lens motor and contacts must Although there are several variations of Nikon 18-55mm kit lenses, most if not all of them have an AF/MF switch on the lens as well. Have you checked the switch on the lens to see if it has been moved? If the camera menu has AF turned off but the lens switch is set to AF you may not be able to move the focus ring on the lens. Good riddance. Nikon's 18-55mm P is extraordinary in that unlike every other 18-55mm kit lens, its new stepper autofocus motor lets it focus essentially instantly, even in near total darkness, even on the cheapest D3300 camera. It focuses so close that you won't need a macro lens. Nikon D3200 video focusing. By default, the D3200 doesn't AF during recording, but you can always trigger an AF cycle by half-pressing the shutter button. Single-shot or full-time servo AF (AF-F) for continuous AF during recording. Focus motor noise with kit lens is very audible in sound track, so probably best not to select continuous AF when When you activate live view, the camera uses contrast detection. Contrast detection is available only in the live view mode because it needs the camera's sensor. For more details about how these technologies work more, see this Fstoppers article: The Difference Between a DSLR's Viewfinder Autofocus and Live View Autofocus 18-55mm Nikon lens won't autofocus. Repair or Replace Started Mar 22, 2007 | Discussions Forum Threaded view JMSprout • New Member • Posts: 6 18-55mm Nikon lens won't autofocus. Repair or Replace Mar 22, 2007 One year to the day from when I purchased my D50 with 18-55mm lens, the lens decided to stop autofocusing between 35 and 55mm. 6UZn.