A arbitrary (with familiar teardrop shape)
AR aluminumreflector
B flame (smooth)
C cone shape
CA candle
F flame (irregular)
G globe shape
GT globe–tubular
MR multifacetedmirror-reflector
P pear shape
PAR parabolicaluminizedreflector
PS pear–straight neck
R reflector
S straight side
T tubular
Lamp Bases
Incandescent lamps have a base at one end,
although some tubular lamps have bases at
both ends. All bases conduct current from
the electrical supply into the lamp (figure
6.3); most bases also support the lamp
physically, but many kinds of PAR lamps can
be supported by their bulbs.
The most frequently used is the medium
base; its name describes its size. Smaller
lamps have smaller bases, includingbayo-
net, bipin, candelabra, intermediate, minia-
ture, mini-candelabra (“mini-can”), twist-
and-lock (TAL),andtwo-pinbases. Larger
lamps have larger bases, includingmogul
screw and medium and mogulbipostbases.
The bipin and bipost bases orient the fila-
ment position, providing rotational align-
ment for optical control. Bayonet and
prefocus medium and mogul bases also
locate the filament in the exact predeter-
mined position required for optical instru-
ments and searchlights.
Filaments
All incandescent lamps contain a filament,
which is more or less centered within the
bulb. A filament is a length of tungsten wire;
tungsten is used because of its high melting
INTERIOR LIGHTING FOR DESIGNERS