Re: Star Trails in 3d

[P3D Dr. George A. Themelis <fj834@xxxxxxxxxxxxxxxxxxxxx>]

>I always thought that the "bulb" setting had something to do with
>manually firing a flash "bulb" whilst the shutter was open...anyone out
>there know for sure?

No.  What you just described is known as "open flash", a technique for use
with any flash (not just flash bulbs):  You leave the shutter open and fire
the flash once or a couple of times.  One application for this is to freeze
motion (leave shutter open in dark, trigger flash, short flash duration
will freeze things more effectively than the fastest camera shutter speeds)

The "B" setting lets you keep the shutter open.  You normally use "B" for 
time exposures (anything more than 1 sec or the camera's longest exposure 
time) but you can use it for anything else you want to do with an open
shutter.


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