Page 4 - SAFAR

THE "SAFAR " CINEMATOGRAPH PROJECTOR ...

TYPE PEM
..
for 16mm SOUND FILM (SMPE STANDARD)

The PEM projector is intended for operation on alternating current mains (A.C. )
ONLY, and provision is made for simple and rapid adjustment on voltages from 110
to 240 at supply frequencies between 40 and 60 cycles per second.

The projector is primarily intended for the projection of 16mm sub-standard
sou nd films made to the Society of Motion Picture Engineers' standards, at a speed of
'24 frames per second. The variable speed control fi tted to the motor will allow
project ion of 16m m silent fi I ms at their correct speed of 16 frames per second ;
although the speed of the motor is variable over a wide range, the selected speed is
mai ntained wit hin close limits by a sensitive electro-mechanical centrifugal governor.

The projector is fitted with a standard lens of SOmm focal length, with an aperture
of f. I :1.6, giving a screen image of approximatel y 10 feet by 8 feet with a projector to
screen distance ("throw ") of 50 feet. The provision of su b-standard lenses of shorter
focal length is the subject of experiment by d~e manufacturers at the moment ; a lens
of 25m m focal length will be avai lable sho rt ly, and othe r sizes will follow. These lenses
will, of cou rse, give a larger scree n image fo r t he same throw, or a sim ilar-sized image
for a shorter throw.

The opt ical system is based on a !amp of 250 watts rating at 110 volts, used with
aspherical mirror, duo-condenser unit and a prism. All o ptic glass surfaces are coated,
o r "bloomed," and a bright screen image is obtainable up to a rna xi mum throw of
50j60 feet. The lamp is a standard type with a pre-focus base. Lam ps of similar
voltage, but rated at 300 and 300 watts may be used wit hout any adjustme nt to the
projector. A lamp of 250 is supplied as standard, but other wattages may be obtai ned
on request. For lamps ove r 300 watts, i.e., 400 and 500 watts, an external t ransfo rme r
must be used; t he projector in put voltage selecto r is set at 110 volts. The transfo r mer
used must be capable of supplying a total wattage equal or more than t he lamp wattage
plus 100 watts. For exam ple, if a 500 watt lamp is used, the transformer must not be
less t han 600 watts output at I I 0 volts.

The projector is fully equipped with ail necessary electrical and mechan ical
controls, and so supplementary equipment or control is necessary. All moving parts
are lubricated by wick-feed oil lines from a cent ral oil container, which has only to be
replenished monthly for normal use, o r weekly if the projecto r is in more or less
continual use. The motor, blower, and intermittent/shutter shaft ru n on ball-bearings
which are seal greased and will not require more than an nual at.te ntio n. All consumable
components such as lamps and valves, etc. , are readily accessible, and maintenance of
the whole projector and servici ng is sim ple. The removal of fou r nuts a l low~ t he re-
moval of the complete projector un it fro m its cabi net, enabli ng all parts of the