The AF 40mm f/2 extended TTArtisan's autofocus range into full-frame standard primes after the company established itself with manual APS-C and rangefinder-style lenses, pitched as a compact alternative to first-party 40mm and 50mm autofocus primes.
Construction is 9 elements in 6 groups, including aspherical and ED elements, in an all-metal 5052 aviation-aluminium barrel. It focuses via a stepping motor to 0.4m, takes 52mm filters, weighs approximately 166-176g, and uses a 7-blade clicked aperture ring. Angle of view is about 57 degrees.
As a standard-length full-frame prime it renders a natural perspective close to the human eye, useful as a walkaround lens rather than a specialist portrait or landscape optic. The modest blade count gives a slightly angular bokeh shape versus rounder rivals at similar prices.
Sold in Sony E, Nikon Z and L-mount versions, all now listed as discontinued or sold out by TTArtisan, making used examples the main route to this lens. Buyers should test autofocus speed and accuracy on their exact body, since third-party AF tuning can lag behind camera firmware updates.