The question of equivalent full frame focal lengths of the Fujifilm GF and Hasselblad XCD lenses comes up over and over. I thought I’d post that information here, and then I can link to it when the topic comes up again.
There are three common ways to calculate equivalent focal lengths: by sensor width, by sensor height, and by sensor diagonal. The equivalent FF focal length has the same angle of view as the MF sensor in that direction. It is conventional to assume the camera is held in landscape orientation for this calculation.
The primes:
The zooms, with both ends of the range calculated:
For Hasselblad lenses, you can refer to their datasheets for even more accurate FLs. I remember the actually FL for XCD21 is 21.8mm, so it is more like 17mm diagonally.
What makes you think their calculations are more accurate than mine?
Please link to their specifications of focal lengths that are different from those engraved on the lenses.
https://cdn.hasselblad.com/datasheets/xcd-lenses/XCD21-Datasheet-en.pdf
https://cdn.hasselblad.com/76a0253f-3df6-49d6-b37c-1934c22a4710_xcd21+datasheet+uk+180420.pdf
“Focal length 21,8 mm”
“Equivalent Focal length (24×36) 17 mm”