Changing Aperture/Iris on Fuji G Mount (GFX) Cameras
For GFX 50s and GFX 50R, press the button on the Smart Expander™ or Smart Adapter™ to toggle between P/S (Programmed Exposure/Shutter Priority) and A/M (Shutter Priority/Manual) exposure modes. The exposure mode chosen is displayed in the viewfinder and on the back LCD display. Use the dial on the camera to control aperture/iris in A or M exposure modes. If an optical image stabilization (OIS) lens is used, turn the IS/OS/VC switch to ON first before pushing the Smart Expander's or Smart Adapter's button. When the IS/OS/VC switch is OFF the same button is used to toggle
For GFX 100 with up-to-date camera firmware and newer cameras, there is either a mode dial to select P, S, A, M exposure modes, or a button on the camera to bring up the P/S/A/M selection.
Changing Aperture/Iris on Fuji X Mount Cameras with Mode Dial
The X-A series, X-M series and X-T100 have a mode dial on the top plate of the camera. Set to A mode or M mode and use the command dial to manually set the aperture/iris. To have the camera choose the aperture/iris value automatically, set to S or P.
Changing Aperture/Iris on Fuji X Mount Cameras without Mode Dial
The X-Pro, X-T (except X-T100/X-T200) and X-E series do not have a mode dial on the top plate of the camera. Under the 'Wrench' tab, Button/Dial Setting, Aperture Setting, choose 'AUTO' to always have the camera choose the aperture/iris value automatically, 'MANUAL' to always choose your own aperture/iris value using the command dial, and 'AUTO+MANUAL' to use the command dial to change the aperture/iris manually until the dial is turned beyond the minimum aperture/iris and the camera will switch to automatically choose the aperture/iris value. The camera will display 'P' or 'S' instead of 'A' or 'M' when it is choosing the aperture/iris value automatically.
Using a Cinema Lens with Manual Iris
On a supported camera (X-T4 or X-H series) you may choose between T-stop display or F-stop display by pressing MENU => 'Wrench' tab => SCREEN SETTING => Page 2 => APERTURE UNIT FOR CINEMA LENS. Choose T NUMBER or F NUMBER.
Note: your cinema lens must have electronic contacts to transmit iris position. Ordinary lenses do not transmit T-stop data and they always show the F-stop.
We recommend against uing auto iris/aperture during video capture. EF mount lenses adjust iris in 1/8th stop steps which may result in visible disruption in the footage or oscillation of the iris. Use A (Aperture Priority) or M (Manual) exposure modes.