Sirui's $149 40mm f2.2 Delivers Weather-Sealed Full-Frame Optics

Sirui is shipping a weather-resistant, full-frame 40mm f2.2 autofocus lens for US$149 — a price point at which Japanese manufacturers have historically offered neither sealing nor a physical aperture ring. The Phoblographer's hands-on review, conducted on a Sony a7r III, awards the lens five out of five stars and calls it effectively unbeatable for its intended use.

The reviewer's verdict is blunt about the competitive implications: "This lens invalidates all the things that the Japanese manufacturers told us for years about not being able to blend image quality, weather resistance, etc. It proves that they simply just didn't want to do it. But Sirui did it, and they're not charging a whole lot of money either."

What does the lens actually offer?

The Sirui Swift 40mm f2.2 ships alongside a companion 20mm f2.4 announced in the same launch. The reviewed optic's specifications, drawn from the company's press release, include:

• 40mm focal length, f2.2 maximum aperture, 9 rounded blades
• Optical construction of 11 elements in 8 groups, described as all-glass
• STM autofocus motor, integrated aperture ring
• 0.4m minimum focusing distance, 0.14× maximum magnification
• 58mm filter thread, approximately 210g weight
• Mounts: Sony E, Leica L, Nikon Z and Fujifilm X
• Price: US$149

That weight — roughly 210 grams — undercuts most first-party full-frame primes by half or more, and the reviewer frames the lens as fulfilling mirrorless' original promise of smaller, lighter glass relative to DSLR systems.

How does it perform in the field?

Testing paired the lens with a Sony a7r III, though the reviewer notes the pairing may suit Sony's compact a7c-series bodies even better. Street photography was the primary use case, along with experimental work: during the review period the photographer attended an experimental photography workshop and, in their words, "embraced the flaws of blur." Autofocus was reported as fast across varied situations.

Build is plastic but does not feel cheap, according to the review, which compares Sirui's effect on a camera system to that of fellow Chinese maker Viltrox — injecting appeal into systems the reviewer characterizes as otherwise stale.

On image quality, the findings are concise: the lens is "insanely sharp," produces pleasing bokeh, and renders colors the reviewer describes as occasionally a bit muted. Sample images published with the review include both edited files — processed with the publication's own presets — and unedited files, a labeling practice the outlet says is unique among photography publications.

The reviewer's five-star conclusion: "Yes buy the Sirui 40mm f2.2 if you want a small, lightweight, fast, and weather resistant lens for street photography. Due to how affordable this lens is, it's really hard to beat it in every single way."

Notably, the reviewer prefers the simultaneously launched 20mm f2.4 over the 40mm personally, while still endorsing the 40mm's street-photography capabilities — a signal that working photographers may want to evaluate both focal lengths before committing.

What does this change for buyers?

For photographers weighing a compact full-frame prime, the calculus now includes a US$149 option with weather sealing, a de-clicked-style aperture ring and STM autofocus across four mount systems — features that Sony, Nikon and Fujifilm typically reserve for lenses at several times the price. The review unit was loaned by Sirui with no payment exchanged, per the outlet's disclosure standards, and the outlet characterizes the assessment as an in-progress review subject to updates. If the 20mm f2.4 shares this lens's qualities at a similar price, the budget-prime segment could shift further toward Chinese manufacturers in the coming product cycle.