Basically, those APS-C crop calculations that you do when trying to relate an APS-C lens to Full Frame, we are doing that in reverse, multiplying the full frame focal length by 1.7x. What you get when you do this is the following results which indicate that the fastest GFX will have an equivalence FF aperture value of F/1.6.
Fujifilm GF Lens to Full Frame 35mm Field of View/Depth of Field Conversion
- GF 23mm f/4.0 // FF 18mm f/3.2
- GF 32-64mm f/4.0 // FF 25-51mm f/3.2
- GF 45mm f/2.8 // FF 36mm f/2.2
- GF 63mm f/2.8 // FF 50mm f/2.2
- GF 110mm f/2.0 // FF 87mm f/1.6
- GF 120mm f/4.0 // FF 95mm f/3.2
So, there you have it. You 50mm junkies will need to get your hands on the 63mm lens, the bokeh addicts out there will need to go for that one or the 45mm or 110mm. In all, three fast prime lenses to help get the system kicked off isn’t bad. It will be interesting to see if Fujifilm pushes the envelope and adds faster glass to the system, even though those lenses would likely have to be enormous.