View Full Version : Whats' in a bulb?


Jeff Whitley
May 10th, 2008, 05:15 PM
I need some help here.

Comparing a light kit with a shop light from a hardware store.
Comparatively speaking the bulbs look the same, but what are the differences? If a bulb goes out in my kit can I just go down to the hardware store and buy a bulb? Would there be a color difference in between the new bulb from the hardware store and another light from my kit?


Thanks, <'/))))><

Brian Drysdale
May 11th, 2008, 03:13 AM
Film lighting bulbs are usually different sizes to those found in domestic or industrial fittings. You might find there's a trade off for longer life as against a higher colour temperature in film lights, although most quartz bulbs tend to be pretty close to the film light colour temperature of 3200k.

With non-film fluorescents, you can find strange colour spikes, which video is more tolerant to because of it's smaller colour space compared to film. They also tend not to be the correct 3,200K.

Jack Walker
May 11th, 2008, 03:21 AM
Slightly off topic, but I will make my once a year (beginning this year) comment about using the term "bulb."

Generally a bulb is big and screwed into the light fixture in the bathroom, or it is brown, a bit dirty, and planted in the garden.

The piece of glass with metal contacts on it and a filament or gas inside is a "lamp."

The bigger thing that the "lamp" goes into is a lighting instrument or an instrument or whatever name the instrument goes by (redhead, baby, tota, leko) or in general terms it is just a light.

In the theater: The lamp just blew in that light.
In the home: The bulb just burned out in that lamp.

Bulbs screw into lamps in household lighting. Lamps plug/snap/push into instruments in the lighting for photos, video, film, theater worlds.

Nevertheless, the term bulb will be used by many forever I suspect.

Jeff Whitley
May 11th, 2008, 04:50 AM
Brian thanks,

I had bought a light kit off ebay a long time ago, britek is the brand name. Cheap but It was all I could afford at the time. The lamp appears to be of the Halogen type, one that would perhaps come in a shop light, actually looks the same a first glance haven't looked closely yet.

I have to do an interview shoot this Tuesday with the mayor of a local town and I wanted to change one of the lamps to a lower wattage for a fill light and let the 1K light be my key for this shoot. I was worried about the variation in color temp being a big issue.

Brian Drysdale
May 11th, 2008, 05:52 AM
Slightly off topic, but I will make my once a year (beginning this year) comment about using the term "bulb."

Generally a bulb is big and screwed into the light fixture in the bathroom, or it is brown, a bit dirty, and planted in the garden.

The piece of glass with metal contacts on it and a filament or gas inside is a "lamp."


Lots of terms used on a film set - changing a "bubble" is commonly used, "globe" gets floated sometimes. In the "Set Lighting Technican's Handbook" an industry standard book, they have "Bulb Tables" which covers all types from photofloods to HMI "bulbs". I suspect in the real world, lamp could get confused with a light fixture (usually a practical e.g. a table lamp), whereas a bulb can only really mean one thing.

I shouldn't get too excited about it as long the spark knows the different types and changes them correctly.

Frank Simpson
May 11th, 2008, 10:15 PM
I've always enjoyed the joke:
Q: How many stagehands does it take to change a lightbulb?
A: None! It's a LAMP!!!!!

In my personal nomenclature, a "bulb" is an incandescent source that can be handled with bare hands, a "lamp" must be handled indirectly, and flourescents are "tubes".

Brian Drysdale
May 12th, 2008, 02:54 AM
I've always enjoyed the joke:
Q: How many stagehands does it take to change a lightbulb?
A: None! It's a LAMP!!!!!

In my personal nomenclature, a "bulb" is an incandescent source that can be handled with bare hands, a "lamp" must be handled indirectly, and flourescents are "tubes".

That book does list the fluorescent tubes in the "Bulb Tables" and I'd never call one of those a bulb. In the end, on a busy set, it's less confusing to just to ask someone to change the bulb (or bubble) than to change the lamp (which could mean a shortened version of lamphead - the lighting fixture itself). Technically they're lamps, but for quick communication it's best not to get too hung up.