Here's a Westinghouse 375W Movieflood lamp with a very short lifespan of 4 hours.
Voltage: 115-120V
Current: 2.99A
Lamp life: 4 hours
Filament: C-9
Lamp shape: R30
Base: Medium E26 Brass
Usually photoflood incandescent lamps (Like Photolita 3400K from Philips lighting Eurpoe) have such short lifetime because they are severally overdriven.
By the way because this lamp have a single coil filament its need very high current in order to reach high temperature, result in less efficient lamp then coiled coil filament lamp.
Hey I found two of those in my Grand Mothers basement, they even had the mounting base for them, she said they dated back from when they use to make home movies on film
I have an NOS movie flood light from the 50s with two GE 375w R-40 spotlights. Pretty bright. But I also have a GE 500w R-40 photoflood with a 6 hour life, it's bright! I mean, BRIGHT!
By the way because this lamp have a single coil filament its need very high current in order to reach high temperature, result in less efficient lamp then coiled coil filament lamp.