Like their name suggests, golfball light bulbs are small, round light bulbs designed for use in more decorative fixtures, or where space is at a premium.
They are most commonly seen in smaller desk lamps or wall lights and are sometimes referred to as ‘round’ light bulbs (although this can be quite an ambiguous term when it comes to light bulbs).
As golfball light bulbs are used in a variety of fittings, there are many different styles and bases available. They are commonly fitted with either a B22d bayonet cap (sometimes abbreviated to BC), or an E27 Edison screw (ES) base. The B22d cap is the ‘push and twist’ type of fitting that is used on the majority of lamps in the UK, while the E27 is the screw-in type that is more common in Europe and the US.
Other types of base include B15 small bayonet cap (SBC) and E14 small Edison screw (SES). These are simply smaller versions of bayonet and Edison caps, used primarily on smaller lamps and fittings.
Golf ball light bulbs are quite distinctive as the light bulb is often not much larger than its base. Think of a golfball sat on a very wide tee. It is easy to confuse golfball light bulbs with GLS light bulbs when shopping online, as they can sometimes look quite similar when viewed on a web page.
The CFL (Compact Fluorescent Lamp) light bulb was the early replacement for high-energy light bulbs, but they often don’t look like their incandescent counterparts. It is instead a narrow fluorescent tube that is turned into a compact shape (hence its name). It is designed to be a direct, energy-saving replacement, so it is compatible with existing fittings, but it looks completely different.
As golfball light bulbs are so small, there are fewer CFL equivalents. LED golfball light bulbs, however, have been designed to look like the incandescent light bulbs they supersede. They have the classic golfball shape and as the technology develops, they are beginning to look more like traditional light bulbs.
These will often be opaque (sometimes described as ‘pearl’ or ‘opal’) and they are made out of glass or heat-resistant thermal plastic. Many have a white plastic base to hide the light bulb’s componentry, but there are now models available that are completely transparent.