The specs and style of the TTArtisan 250mm F5.6 reflex bokeh lens reference a specific vintage optic, the Minolta RF Rokkor 250mm F5.6 lens.
UPDATES: It's in stock and you can buy it at Pergear.
Focal length: 250mm
Fixed aperture: F5.6
Coverage area: full frame
Mount: M42
Viewing angle: 10 degrees
Optical design: 6 elements in 5 groups
Filter mounting diameter: 67 mm
Minimum shooting distance: 2 m
Weight: approx. 380 g
The TTArtisan 250mm F5.6 Reflex Donut Bokeh is only 6.5 cm long (without hood) and 7.2 cm in diameter and weighs 380 g, so it fits perfectly even on small camera bodies. The M42 mount makes the lens adaptable to almost any system, and the opacity circle is slightly larger than required for full frame, so even on digital medium format systems there is almost no vignetting.
