
The Rollback is a 120 film back for Graflok 23 made by Mercury Works.

The Mercury Rollback 23 is an homage to the classic era of rollfilm: from the early 20th century until the post-WWII industrial boom, medium format cameras made use of an ingenious, inexpensive system for film advancing and frame counting. Numbers were printed on the film’s backing paper (something not possible with cartridge-based film systems). Precisely positioned windows would reveal exactly the numbers that corresponded to the camera’s frame size. Rather than a complex geared system automatically advancing to the correct point for each shot, and another complex geared system advancing a counter, the photographer would do the advancing, peering through a red-tinted window. Whatever number appeared in the window was the current frame’s number. It was like using a magical window that revealed the inner workings of the mysterious Film Camera. Well, because Mercury Works is all about magic windows, we chose to revive this system in a 3D printed variant. Finally you can actually make use of those numbers that are still, to this day, printed on the back of every reputable roll of 120 film. Yes, they are really there: take a look!
This back comes in 2 frame sizes: 6×6 and 6×9.

There is a special “dual knob” version of this back that allows winding in 2 directions: forward and back. This allows you to rewind your film mid-roll to allow for complex multiple exposure series. This is not possible with any other Graflok 23 back due to unidirectional gearing.
The Rollback is designed specifically for Mercury cameras, but will mount on other Graflok 23 cameras as well.
