Nikon’s Z DX lenses are designed for their APS-C DX sensor mirrorless cameras like the Nikon Z50 or Nikon Z30. They can be used on full-frame Z series cameras, which will force APS-C crop mode to engage.

By creating a mount with a large inner diameter and short flange focal distance, compact lenses can be designed that allow more light in, to hit the sensor. Using the latest in design and optical innovations, NIKKOR Z lenses are able to deliver improved low-light performance and edge-to-edge detail in both stills and video.

This also that mirrorless lens adapters need to be appropriately thick in order to make up that difference so that the same lens will mount the proper distance from the film or sensor plane on the mirrorless cameras  which allows the full range of focus from infinity to the minimum focus distance.

The Z system’s large lens mount features a 55mm inner diameter and short 16mm flange focal distance which allow for flexibility in the optical design of NIKKOR Z lenses: with maximum apertures as wide as f/0.95 possible. The internal diameter of the Z mount is 17% larger than the Nikon F mount—it’s also wider than any full-frame mount available (as of 8/23/18).

On a DSLR the Flange Focal Distance must be large enough to allow full movement of the reflecting mirror, hence the  box is larger.

The manufacturer that makes these little lights has closed down. What we have in stock now is all that will be available.

What is Flange Focal Distance The measurement between the lens mount or flange  and film plane is called the Flange Focal Distance.

Difference between FFDs in Z mount mirrorless and F mount DSLRs The Nikon Z mount flange distance – 16mm The Nikon F mount flange distance – 46.5 mm So, the Z mount mirrorless cameras FFD is significantly shorter the the F mount DSLRs.