Quote Originally Posted by hortense
My 150mm, f/4 T* Carl Ziess Sonar CF does not have "T" setting? Question:

1. Should I assume that I must use a cable release that can be locked down for long exposures?
Yes, indeed!
Quote Originally Posted by hortense

2. In searching Googling for this answer, I found an astonishing observation. Ostensibly, after 30-seconds the lens or the shutter on the back closed?
Any comments or guidance would be appreciated.
Maybe the Bulb setting of that individual only reach 30 sec of exposure time?
Shutter on the back?
Never heard such thing as an hasselblad back with shutter!

Get that cable release, put B setting on your CF and shoot away!