I have just started using manual focus and prime lenses with my Olympus E410 (four-thirds).
Intermittently, the aperture value is invisible, both through the viewfinder and in the LCD display. Instead of an f stop, the aperture appears as two dashes: "- -".
When this fault occurs, I cannot adjust the aperture with auto-focus Olympus lenses, and manually-focused shots appear blurred, even if I adjust the aperture on the manual focus lens itself.
Do you have any suggestions as to what might be causing this?
Thanks for your time.