My Nikon D5200 works perfectly fine with two of my lenses, 18-140mm and 85mm. But it has an auto-focusing issue with 35 mm f/1.8G lens. The point where it seems to have focused is not as sharp. It doesn't focus on the object but a little behind it. What is the problem and how can it be rectified?
In order to use it properly I have to rely on manual focus.
As Nikon D5X00 cameras lack the micro-focus adjustment feature found in D7X00 cameras, viewfinder front focus and back focus problems cannot be fixed by camera settings.
Fortunately, there is an undocumented mechanical adjustment screw inside the mirror box in D5X00 cameras that can be used to correct this problem. This screw has a 2mm hex socket and is found just behind the bottom edge of the mirror on the right side wall of the mirror box.
After shooting test photos of a lens alignment target, determine whether the camera is front focusing or back focusing. The camera should then be put in mirror lock-up mode and the lens removed, exposing the mirror box. To fix front focus, the screw should be turned counter-clockwise. To fix back focus, the screw should be turned clockwise.It should take only about a quarter-turn of the screw to fine-tune the focus system for your lens.
What you are describing is known as back-focusing. The different tolerances in manufacturing, assembling, and calibration have combined such that your individual camera, when combined with your individual lens, will consistently autofocus slightly behind the subject. See also: What is back-focusing?
This is correctable by calibration. There are several DSLR bodies that provide the user the ability to calibrate the autofocus for individual lenses. Unfortunately, your D5200 is not one of those cameras. You will have to send your camera and lens in to Nikon to have the pair calibrated to each other.
