Sirui has launched a new range of budget-friendly full frame autofocus prime lenses. The first two Swift series lenses are a 20mm F2.4 and a 40mm F2.2. Both come in L-Mount or Sony E-mount. Sirui says Fujifilm X-mount versions are also on the way, which is an APS-C system rather than full frame.
Compact design
The Swift primes are small and light enough to carry everywhere. The L-Mount 20mm weighs 0.467 lbs (212 g) and the 40mm weighs 0.474 lbs (215 g). Both Sony E-mount lenses are a little lighter at 207 g and 210 g.
Both focal lengths measure 2.45 inches (62.3 mm) long in Sony E-mount and about 2.36 inches (60 mm) in L-Mount. Filter size is 58 mm.
Optical construction
The Swift 20mm uses 11 elements in 9 groups. These include two aspherical elements, two ED (Extra Low Dispersion) elements and two HRI (High Refractive Index) elements. The 40mm has 11 elements in 8 groups, with one aspherical element and two ED elements.
Sirui points out that the Swift primes use all-glass optics, while other budget lenses can rely on cheaper plastic elements. The company also promises low distortion and natural color rendering.
Autofocus
Sirui says the Swift primes use an STM (stepper motor) for quick, smooth autofocus. The company also promises minimal focus breathing, so your image shouldn’t change size as you pull focus. Close focus is 0.65 feet (0.2 meters) for the 20mm and 1.31 feet (0.4 meters) for the 40mm.
A physical switch flips between manual and autofocus. A custom button can be assigned to instant focus lock.
Wide maximum apertures
The Swift 20mm has a wide maximum aperture of F2.4. The 40mm is a little faster at F2.2. Both lenses use a 9-blade iris, so you should get smooth, round bokeh.
A manual aperture ring is on board, but unfortunately it clicks. Sirui advertises the clicks as precise control. For video shooters, it means you can’t adjust exposure smoothly mid-shot.
Other features
The Swift primes are dust-, smudge- and weather-resistant. A lens hood comes as standard. Sirui also offers a 3-year free replacement warranty for “non-human damage.”
What we think
Sirui’s new Swift 20mm and 40mm primes promise good image quality at a very low price. Both lenses are compact and light, which makes them handy all-day walkabout glass.
The 20mm gives you a wide perspective for group shots, cityscapes and vlogging to camera. The 40mm suits portraits, street videography and close-ups. Wide apertures on both help in low light and give you a shallow depth of field. If you’ve been thinking about adding a prime to your kit bag, the Swift series should be high on your list.
Pricing and availability
The Sirui Swift 20mm F2.4 and 40mm F2.2 autofocus primes cost $149 each. They are available to preorder, and Sirui says shipping starts Nov. 6.
