Do not use flash bulb
following types of film because it does not
Flash bulb of guide number 14 with ASA
25 film, guide number 20 with ASA 800,
and guide number 28 with ASA 400 or higher
(or unit) with
In flash photography using a conventional
electronic flash unit or flash bulb when the
proper f/stop is set according to the guide
number, there is a heavy drain on the mercury
battery. Therefore, be sure to return the aper-
ture ring to the " A " position after shooting.
When the subject is too far or too close,
the shutter button cannot be depressed.