The eyepiece on the Fuji GFX EVF can be adjusted to a -4 diopter value. Unfortunately my right eye requires a -6.5 correction. Rather than having to use my glasses when shooting, I added a -3 diopter lens so that I can properly adjust the GFX EVF to correct for my vision. Although most of the camera manufactures offer some type of corrective lens, the diopter lens size of the Canon fits the GFX.
I used a Canon -3 Diopter from a Canon 1DS Mk 3 which is available from B&H (B&H # CADALEG3 MFR # 2198B001) for $34.95. The diopter is also available in -1, -2 and -4 strengths. In order to remove the glass from the Canon Fitting, it is necessary to remove the plastic structure surrounding the lens. The glass lens is thin and brittle so great care must be taken to remove the plastic without damaging the glass. I used a Dremel Tool with abrasive cutting wheels to remove the plastic. Cut the plastic completely and don't try to force the glass out of the assembly. To install the diopter, remove the rubber eyecup from the GFX and slide the lens over the existing lens. The rubber eyecup will securely hold the new lens in place but since the eyecup doesn't fully lock into place I secured it with a plastic cable tie.. I hope the Fuji Factory offers diopters in the future for a cleaner installation, but the Canon lens will have to work in the meantime.
I used a Canon -3 Diopter from a Canon 1DS Mk 3 which is available from B&H (B&H # CADALEG3 MFR # 2198B001) for $34.95. The diopter is also available in -1, -2 and -4 strengths. In order to remove the glass from the Canon Fitting, it is necessary to remove the plastic structure surrounding the lens. The glass lens is thin and brittle so great care must be taken to remove the plastic without damaging the glass. I used a Dremel Tool with abrasive cutting wheels to remove the plastic. Cut the plastic completely and don't try to force the glass out of the assembly. To install the diopter, remove the rubber eyecup from the GFX and slide the lens over the existing lens. The rubber eyecup will securely hold the new lens in place but since the eyecup doesn't fully lock into place I secured it with a plastic cable tie.. I hope the Fuji Factory offers diopters in the future for a cleaner installation, but the Canon lens will have to work in the meantime.