Hey guys, I recently got a bunch of used lighting and in it there were two of these pin spot lights.

The bulb socket is not the screw in type, it's smooth on the inside.

Any ideas of what type of bulb?

Sam Pearce

Not sure, but could possibly be a "bayonet" type bulb. Would suggest that you look up a "Theatrical Lighting" supplier.

FWIW

Cheers!

Just by looking at the pictures.... looks like a BTL style base.

Sam,
That looks like a Strand Pattern 23 fixture.
If that's in fact what it is (it should say on the fixture), you would use a 500W T-17 or T-1 lamp.
Check with your local (or online) theatrical lamp supplier for this lamp. It's starting to get to be a VERY old fixture, and this lamp may not be as common as it once was.

The base is commonly called a "pre-focus" or "bayonet" base.
A BTL is a lamp style, not a base style, and it's far to tall to use in this fixture.

Yes, it is a old Rank Strand theatre spot. I have changed successfully the socket so I could use more common bulbs (socket GY 9.5). Of course there are modern constructions that are brighter but I like these old theatre spots. They are also nice decoration when used in a display or maybe in front of your stage.

Great find Guy! Im getting mist eyed thinking of the times Ive almost tumbled from a ladder changing lamps like that. Light was far more challenging Back in the reostat days of dimming when a complex cue called for more lighting guys at the board.
Mike