Tag Archives: Flange back

The “E” in “E-Mount” stands for Eighteen.

A completely useless bit of trivia for you is that the “E” in E-mount stands for eighteen. 18mm is the E-mount flange back distance. That’s the distance between the sensor and the face of the lens mount. The fact the e-mount is only 18mm while most other DSLR systems have a flange back distance of around 40mm means thare are 20mm or more in hand that can be used for adapters to go between the camera body and 3rd party lenses with different mounts.

Here’s a little table of some common flange back distances:

MOUNT FLANGE BACK SPARE/Difference
e-mount 18mm
Sony FZ (F3/F5/F55) 19mm 1mm
Canon EF 44mm 26mm
Nikon F Mount 46.5mm 28.5mm
PL 52mm 34mm
Arri LPL 44mm 26mm
Sony A, Minolta 44.5mm 26.5mm
M42 45.46mm 27.46mm