Brightin Star's latest MF 50mm F2.0 Tri-Sight lens seems fairly normal with its fixed 50mm focal length, but it stands out from the crowd by boasting user-selectable 'rendering modes' which alter the character of out of focus highlight points. Choose from Smooth bokeh (soft highlights), Prime (sharper, more defined highlights) or Foams (dreamy, bubble-like light flares)
The system works using a dedicated control ring positioned between the focus and aperture rings. This moves a floating group of lens elements back or forth within the barrel to vary the focus distance, altering the convergence characteristics of light rays passing through the lens. This then results in the change in bokeh style, depending upon where the light converges relative to the focal plane.
This feature alone would make the MF 50mm F2.0 Tri-Sight pretty special, but Brightin Star also includes four circular plate inserts with novelty aperture cut-outs. These turn what would otherwise be round out of focus highlights into a choice of butterfly, star, triangle, or four-leaf clover shapes. The effect is certainly eye catching, though not entirely unique, as Lomography implemented a similar feature in its Petzval and Daguerreotype Achromat lenses. Brightin Star's method of fitting the inserts is more unusual though, as rather than slotting them down into the barrel, you instead unscrew a locking ring at the lens mount, fit the plate, then re-attach the ring. There is also a slot in the barrel, but this is designed to take conventional drop-in 37.5mm filters.
The barrel itself is made entirely of metal and features a neat retractable hood. Weight ranges between 429g and 454g, and length between 70mm and 74mm, depending on mount option. The aperture diaphragm is comprised of a generous 11 blades and is de-clicked for smooth aperture transitions when shooting video. Videographers may also appreciate the included detachable focus lever that helps with fine focus adjustments - useful, as the MF 50mm F2.0 Tri-Sight does not have autofocus.
Inside is a 7-element optical stack arranged in 6 groups. Up front is a custom-made protective lens made from precision-ground, ultra-thin glass measuring just 0.7mm thick. This is necessary as the floating group of elements which adjust the bokeh appearance actually extend forward of the main barrel when in Foams mode, making the front element more vulnerable to damage. Consequently, Brightin Star recommends the lens is stored with the bokeh control set to Prime mode, where the barrel is retracted.
The Brightin Star MF 50mm F2.0 Tri-Sight lens is available now for full-frame and APS-C Sony E, Canon RF, Nikon Z, and L-mount cameras, priced at $349.99/£263.99
