Put a 3 stop on this weekend so I could shoot wide open with the 35mm in the bright SoCal sun. The HUD in the OVF ramps up and down on it's own. However it was so dim I could not make out exposure comp. Then I realized it was setting the HUD brightness based on the sensor with a 3 stop ND filter in front of it. With no manual control of the brightness of the HUD in the OVF the only work around is to use the EVF. Bummer because the OVF is so nice.