Using a DX Lens on an FX Camera
What you lose and what you gain.
This short article will address the issue of using a DX lens on an FX camera body.
Many of us have upgraded to mirrorless cameras. When you do, you face the dilemma of what to do with your old lenses incompatible with the mirrorless camera mount.
Solution
Fortunately, the camera manufacturers have stepped up to the problem and provided adapters that enable you to use your old mount lenses on the new mirrorless mount. Your old FX lenses will work great when you use the adapter.
Problem Solved?
Problem solved. Right? Not exactly. Some of us upgraded from a DX camera with DX lenses. What happens to us?
The good news is that the adapter will work on your DX lenses too. However, the FX mirrorless camera will produce an image file the size of the DX sensor. The same happens if you use a DX lens on an FX DSLR camera with the same lens mount.
Here Is What Happens
The FX sensor is larger than the DX sensor, as seen in the image below.
For example, the FX file size on my Nikon Z5 is 6016 x 4016. When I put on my adapter and use a DX lens, the file size drops to 3936 x 2624. The camera automatically reduces the file size.
