Viltrox EF-FX1 OIS not properly working In: EOSHD Posted October 12 · Report reply Thanks for the reply. Actually, the EF-FX1 is a simple adapter, not the speedbooster one. I contacted Viltrox, they just told me to update the firmware. Basically I tried every firmware. The only one kind of working is the latest one. In the Fuji X-T3 menu, stabilization setting is greyed out (you can normally chose if IS is always on or just when you take the picture). So, so far, IS isn't supported by the Viltrox EF-FX1 adapter. Good to know... Do you get the stablization working with the fringer ?