Ultra short 18 mm flange distance on FF has more vignetting.: Sony Alpha Full Frame E-mount Talk Forum: Digital Photography Review
Re: Why the very short flange focal distance of 16mm for Z mount?: Nikon Z Mirrorless Talk Forum: Digital Photography Review
![terminology - What exactly is focal length when there is also flange focal distance? - Photography Stack Exchange terminology - What exactly is focal length when there is also flange focal distance? - Photography Stack Exchange](https://i.imgur.com/V1WySTT.gif)