The new 28mm APS-C sensors from Sony (32MP) and e2v (64MP) promise to fill the gap in image circle size between C-mount and full frame making it possible to design much higher resolution systems that are still relatively compact. Traditionally a large format lens with an F-mount or M42 thread would be used for a sensor of this size. Unfortunately both of these formats are far from optimal when it comes to precision machine vision applications due to issues with standardization, stability and overall system size.

TFL is a new mount specification adopted as a standard by the Japan Industrial Imaging Association (JIIA) in 2017, and it is an excellent solution to all of the problems faced by other mount types. It features an M35 x 0.75 metric thread and a back flange distance of 17.526mm, identical to C-mount. This means lenses with a TFL mount can offer the same robustness and ease of use as a C-mount but accommodate a larger sensor size. The short back focal length allows for improved optical performance and a more compact, lightweight design. When compared to large format C-mount lenses, the additional internal diameter allows for designs with higher optical resolution (lp/mm).

More about the lenses can be found here.