gezakurczveil

Awesome, thank you Tom!

Hi all, I have a Hasselblad 250 mm SA CF lens on a non-native body. In order to keep the internal shutter open at all times, I leave the lens in F-mode. About once a month (I use the lens sporadically) I run into an issue where I am using the lens at f/8 and I hear a click from the lens only to see that the aperture is now at f/5.6. Adjusting the aperture ring, shifting the DOF switch on/off, or gently tapping the lens do nothing, the lens stays fully open no matter what. But when I switch out of F-mode, the internal shutter close, and after cocking it again I finally regain full control of the aperture diaphragm. Does anybody know why this is happening? I would like to prevent this from happening as it requires me to unmount the lens from the body and this can introduce dust on the sensor when I am out in the field. I have reached out to a popular Hassy repair person, who suggested that I contact Hasselblad directly. Hasselblad told me that they no longer service this lens, and that I should exercise the DOF next time it happens. I have tried that and it still did not restore control of the aperture until the shutter was cocked. Thanks.