Why the name Quarter Twenty?

The term or name Quarter Twenty comes from a measurement of a common bolt thread which is a 1/4 inch wide and uses 20 threads per inch. This standard has been adopted by camera and tripod manufactures since the dawn of photography and adopted into cinematography when motion picture cameras came along. Today it's used almost universally for smaller cameras and tripods, both stills and video, accessories of all types for both professional and consumer cameras. and more recently with the advent of cages and accessories for mobile. We think its the perfect symbol of image based creators as a standard used by all who love making images.

Here's what wikipedia has to say about the standard.

"Per ISO 1222:2010,[1] the current tripod bolt thread standard for attaching the camera calls for a 1/4-20 UNC[2]or 3/8-16 UNC thread.[3] Most consumer cameras are fitted with 1/4-20 UNC threads. Larger, professional cameras and lenses may be fitted with 3/8-16 UNC threads, plus a removable 1/4-20 UNC adapter, allowing them to be mounted on a tripod using either standard.

Historically, The Royal Photographic Society recommended the thread standard for attaching older cameras to tripods was 3/16-24 BSW (3/16 inch nominal diameter, 24 threads per inch), or 1/4-20 BSW[4] for smaller cameras and 3/8-16 BSW[5] for larger cameras and pan/tilt heads. In this application, the BSW and UNC thread profiles are similar enough that one can mount a modern camera on a legacy tripod and vice versa. The UNC threads are at a 60-degree angle and flattened, whereas the BSW are at a 55-degree angle and rounded crest. However, at least one English manufacturer uses No.1 B.A. (British Association) for its tripod mount thread."