Why does the diameter of the reflector have so much effect on the
output-(candlepower)--of bulbs having the same power input?? i.e.
#4509-PAR-36 4.45"Ø 110,000cp
#4537-PAR-46 5.70"Ø 200,000cp

And then we have the newer import cars using 2.5" reflectors (+ a
condensing lens of similar dia.) which are apparently equal to the
larger rectangular bulbs of conventional design.

then there are the hand lanterns with QH peanut bulbs of 50 to 100 watts
boasting 500,000 to 1,000,000 cp. Jerry