Problems with the Nikon D750 Lens Mount
Problems with the Nikon D750 lens mount resulting in soft images. Here at Cameracal, we recently came across the following problem and ultimately the solution. We would therefore advise all Nikon D750 owners to be aware of this potential problem, especially wedding and portrait professionals.
As we all know the Nikon D750 is a popular camera, especially for those who are looking for a "budget" full frame alternative to the Nikon D850. As a result this model tends to be a popular choice for Wedding and Portrait photographers.
Were as the D750 is a capable alternative, it does not match the build quality of its more expensive sibling as a result we have encountered various issues, the most serious tends to be camera mount related.
We have had several clients (all of whom are wedding / portrait photographers) complain of images appearing soft. We would have normally put this down to a need to calibrate the camera and lenses (thus compensation for any lens element and AF sensor misalignment), in this case it was more involved.
A casual comparison of the Nikon D750 and Nikon D850 lens mounts look identical.
The D750's front body is constructed of carbon composite (as opposed to magnesium alloy) and as such not as durable. It seems that the constant mounting and dismounting of lenses results in movement of the D750 lens mount. An issue we have yet to see with the Nikon D850 lens mount. Any movement in the lens mount can, as we have seen, result in images appearing soft on either side of the image.
We have as mentioned had several instances in which a clients has experienced this problem. Inspection of their camera has found that the lens bayonet mount was found to be loose and that the screws that anchor the mount to the body needed a quarter of turn to tightened them and thus secure the mount.
Subsequent tests having tightened the mount shows this eradicates the problem.
So the moral of the story? If you are a wedding / portrait photographer and are are constantly changing lenses (and are using heavy glass objective lenses such as 14-24mm F2.8, 24-70mm F2.8 or 70-200mm F2.8) it is best to check your lens mount for any excess movement or better still, get us to do it for you. It has become part of our Annual Camera Service for the Nikon D750