The Graflex Revolving Back (RB) Series B is a single-lens reflex roll/sheet film camera from the American Graflex line, fitted with a rotating back that allows the photographer to switch between portrait and landscape framing without turning the camera. It belongs to the early-to-mid 20th century era of large-format SLR press and studio cameras and was positioned as a more affordable sibling to the higher-specification RB Graflex models.

Auction data for the RB Series B is thin: a single recorded UK hammer result from 2009 sold for £320, so a reliable current range cannot be quoted. As of today in 2026, what a Series B is worth at saleroom level depends heavily on completeness of the back, shutter function and lens condition, and buyers should treat that lone figure as indicative rather than a market median.