Ultra-wide primes are tricky: they can look dramatic, but they also expose every weakness in your technique and your lens. If you shoot Sony E, Fujifilm X, or Nikon Z APS-C and want a small lens at a cheap price, this one should be on your radar.
Coming to you from Dylan Goldby, this practical video takes a hard look at the Viltrox AF 9mm f/2.8 Air E lens. Goldby doesn’t treat 9mm like a normal “go wider” option; he treats it like a specific tool with real costs. You hear what Viltrox aimed for with the Air series: lightweight build, simple controls, and an autofocus motor that’s solid even if it’s not built for chasing fast sports. The review is also clear about compromises that matter in the real world, including the lack of weather-sealing and the missing mount gasket he wishes Viltrox had added. If you’re the type who carries a lens everywhere and actually uses it outside, that one detail alone can shape how you pack and how you shoot.
The most useful parts are where Goldby separates “looks sharp on a spec sheet” from “works in your files.” Center sharpness is strong at f/2.8 and f/4, then tightens up more as you stop down, but diffraction shows up once you push into smaller apertures like f/11 and f/16. Corner performance is the real story: the extreme corners go soft and smeared wide open, improve around f/5.6 to f/8, then fall apart again when diffraction takes over. He calls out the mustache-style distortion that can be easy to ignore until you place straight lines near the edges, which is exactly how this kind of lens sneaks up on you. If you’ve ever wondered why your wide shots feel “off” even when exposure and focus look fine, this section will land.
Key SpecsFocal length: 9mm (35mm equivalent: 13.5mm)
Maximum aperture: f/2.8
Minimum aperture: f/16
Mounts: Sony E, Fujifilm X, Nikon Z
Format coverage: APS-C
Minimum focus distance: 5.11" (12.98 cm)
Maximum magnification: 0.15x (1:6.66)
Optical design: 13 elements in 11 groups
Diaphragm blades: 7
Focus: autofocus
Image stabilization: none
Filter size: 58 mm (front)
Dimensions: 2.6" × 2.2" (65 mm × 56.4 mm)
Weight: 6.2 oz (175 g)
Where the video gets more interesting is when Goldby stops treating flaws as “bad” and starts treating them as choices you can use. He describes flare and ghosting as present but mostly controlled, then points out a very specific flare pattern that shows up at certain angles, including concentric circles and a larger red ring when the sun is placed just right. That’s the kind of behior you either oid completely or build shots around, and he shows how to do both without turning it into a science project. He also talks about close focus as a real creative lever and compares that style of shooting to what he likes about the Tamron 11-20mm F/2.8 Di III-A RXD. If you tend to default to safe compositions with wide lenses, this is the part that pushes you into weirder, better frames.
Goldby also names alternatives in a way that helps you decide what you’re paying for, not what you’re “missing.” The XF 8mm f/3.5 R WR Lens gets a nod for weather-sealing, higher sharpness, and an aperture ring, with the tradeoff being cost. He mentions an equally priced 7Artisans option with a mount gasket, but also says the Viltrox wins on technical results, which frames the choice as durability detail versus optical performance. Then there’s the manual-focus Venus Optics Laowa 9mm f/2.8 Zero-D, where straighter lines and stronger corner performance come with the obvious friction of focusing yourself. If you already know you hate correcting distortion and you love architecture, that one sentence can se you a lot of annoyance later. Check out the video above for the full rundown from Goldby.