Re: (meteorobs) Re: photographing the night sky

In a message dated 98-06-15 11:09:00 EDT, you write:

 A T setting starts the exposure when you press the shutter button and holds
 the shutter button open until you press the button again. A B setting means
 you have to hold the shutter button ( or the cable release ) down. However,
 you can buy cable releases that do the holding down for you. One I own has
 a clamp screw to hold it down: another has a ring around the plunger - you
 press the plunger down to start the exposure and press the ring to finish.
 My only worry about these gadgets is that they make it easy to apply
 unnecessary force to the camera's shutter button.

I've also had times with the B setting that the plunger releases the exposure
prematurily. I'd push and lock it in and go on to observe. then sometimes
later I would come back and find that the exposure was stopped some unknown
time after it began. Very frustrating. But it doesn't happen too often.