Xref: utzoo sci.electronics:4800 rec.photo:4300
Path: utzoo!attcan!uunet!lll-winken!ncis.llnl.gov!helios.ee.lbl.gov!nosc!ucsd!rutgers!att!homxb!houxs!beyer
From: beyer@houxs.ATT.COM (J.BEYER)
Newsgroups: sci.electronics,rec.photo
Subject: Re: Flashbulbs (was something stupid and illegal...)
Summary: Bulb shutter setting has nothing to do with flash bulbs...
Message-ID: <1139@houxs.ATT.COM>
Date: 20 Jan 89 14:20:59 GMT
References: <9844@sequent.UUCP> <2818@osiris.UUCP>
Organization: AT&T BL Holmdel NJ USA
Lines: 42

In article <2818@osiris.UUCP>, consult@osiris.UUCP (Unix Consultation Mailbox ) writes:
> In article <9844@sequent.UUCP> brian@crg1.UUCP (Brian Godfrey) writes:
> >Modern cameras probably don't have provision
> >to sync to bulbs. Cameras in the transition period (1950s to 1980s) did make
> >provision for both schemes while applied to them. My old OM-1 (1975) has 
> >a switch for "FP" or "X". "FP" is for bulbs (stands for Flash Powder??)
> >and "X" is for electronic flash. My old Linhoff (I think it is 1950s
> >vintage) has settings on the shutter for "M" and "X" sync. "M" is also 
> >for bulbs, though I have no idea what it means.
>
FP stands for bulbs designed for focal plane shutters. They have a long
burn time, at least as long as the shutter curtain travel time.
M was for medium delay bulbs. There were also short and long delay bulbs,
but I do not remember (from my reading, I never used any flash bulbs
except some #25B's with a Brownie Hawkeye) their codes.
 
> And then there's the more common but no less mysterious "B" setting,
> which I've always heard "translated" as "bulb", which holds the shutter
> open as long as you hold the shutter release button.  Is this intended
> for syncing to flash bulbs?  (I always used it for exposures longer than
>
B does stand for BULB, but it refers to the squeeze bulb at the end of a long
rubber (in those days, mine is plastic tubing) that can be used for remote control
of a shutter. The shutter stayed open for as long as the bulb was squeezed so
you could adjust exposure time without going to the camera. In the old days,
film was slow enough that this made sense. In fact some manufacturers had
"controlled" leaks so that you could make a fixed time exposure by seeting
the leak rate. I bet the reliability was not very good.

On my shutters there is both B and T positions. On B, the shutter remains open
for as long as I hold the bulb. On T, the shutter opens on the first squeeze
and closes on the second. On some old German shutters, T is called Z
(I believe Zeit is German for Time, but I only took one year of it 30
years ago.)
 
> Phil Kos


-- 
Jean-David Beyer
A.T.&T., Holmdel, New Jersey, 07733
houxs!beyer