{"id":78065,"date":"2025-09-20T07:07:14","date_gmt":"2025-09-20T06:07:14","guid":{"rendered":"https:\/\/phillipreeve.net\/blog\/?p=78065"},"modified":"2025-09-22T15:12:17","modified_gmt":"2025-09-22T14:12:17","slug":"review-viltrox-af-9mm-f-2-8-air-aps-c","status":"publish","type":"post","link":"https:\/\/phillipreeve.net\/blog\/review-viltrox-af-9mm-f-2-8-air-aps-c\/","title":{"rendered":"REVIEW: Viltrox AF 9mm f\/2.8 Air (APS-C)"},"content":{"rendered":"

\"\"<\/p>\n

Introduction<\/span><\/h2>\n

On the same day that Viltrox introduced the AF 14mm f\/4, an affordable autofocus ultra-wide-angle lens for full-frame cameras, they also announced a 9mm f\/2.8 autofocus lens for APS-C cameras \u2014 the widest AF prime lens for crop sensors and another addition to their compact, lightweight Air series.<\/p>\n

\"camera-icon2\"I tested this lens on a Nikon Zfc<\/a> via a Megadap adapter<\/a> (Sample images were taken with a Sony a6700<\/a>)
\n\"\"You can see this review as\u00a0a\u00a0YouTube\u00a0video\u00a0here<\/a>!
\n\"\"Sample images in high resolution here<\/span><\/a>.<\/p>\n

Sample Images<\/span><\/h2>\n
\"\"
Sony a6700 | Viltrox 9mm f\/2.8 Air | f2.8<\/figcaption><\/figure>\n
\"\"
Sony a6700 | Viltrox 9mm f\/2.8 Air | f2.8<\/figcaption><\/figure>\n
\"\"
Sony a6700 | Viltrox 9mm f\/2.8 Air | f6.3<\/figcaption><\/figure>\n
\"\"
Sony a6700 | Viltrox 9mm f\/2.8 Air | f3.5<\/figcaption><\/figure>\n
\"\"
Sony a6700 | Viltrox 9mm f\/2.8 Air | f2.8<\/figcaption><\/figure>\n

<\/p>\n

\"\"
Sony a6700 | Viltrox 9mm f\/2.8 Air | f4<\/figcaption><\/figure>\n
\"\"
Sony a6700 | Viltrox 9mm f\/2.8 Air | f6.3<\/figcaption><\/figure>\n

Most of the sample images in this review and many more can be found in higher resolution here<\/span><\/a>.<\/span><\/p>\n

<\/span><\/p>\n

Specifications<\/span><\/h2>\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Focal Length<\/td>\n9mm<\/td>\n<\/tr>\n
Angle of View<\/td>\n113.8\u00b0<\/td>\n<\/tr>\n
# of Aperture Blades<\/td>\n7<\/td>\n<\/tr>\n
Max Aperture<\/td>\nf\/2.8<\/td>\n<\/tr>\n
Min Aperture<\/td>\nf\/16<\/td>\n<\/tr>\n
Min Focus Distance<\/td>\n0.13 m (0.15X)<\/td>\n<\/tr>\n
Filter Size<\/td>\n58mm<\/td>\n<\/tr>\n
Lens Mount<\/td>\nE, XF, Z<\/td>\n<\/tr>\n
Weight<\/td>\n\u2248175 g (E & X), \u2248190 g (Z)<\/td>\n<\/tr>\n
Size (D x L)<\/td>\n65×56.4 mm (E)
\n65×56.7 mm (X)
\n65×58.4 mm (Z)<\/td>\n<\/tr>\n
Elements\/Group<\/td>\n13\/11<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
\"\"
Lens Construction | Viltrox 9mm f\/2.8 Air<\/figcaption><\/figure>\n\n\n\n
Buy from:<\/strong> Viltrox Store<\/a>, B&H<\/a>, Amazon (anywhere)<\/a>\u00a0 (Affiliate links)
\neBay.com<\/a>, eBay.de<\/a><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Disclosure<\/span><\/h2>\n

The Viltrox AF 9mm 2.8 was kindly provided free of charge by Viltrox for reviewing purpose for a few weeks.<\/p>\n

Handling and Build Quality<\/span><\/h2>\n

As the name suggests, the Viltrox AF 9mm f\/2.8 Air is an autofocus lens. There\u2019s no image stabilization, though at an equivalent focal length of 13.5mm, it\u2019s hardly necessary. The lens feels very light in the hand, and while the build quality doesn\u2019t feel cheap, its mostly plastic construction and light weight mean it lacks a premium feel.<\/p>\n

\"\"
Viltrox 9mm f\/2.8 Air<\/figcaption><\/figure>\n

The main control is the relatively large focusing ring. It doesn\u2019t allow live override in AF mode, and its function can only be set to manual focusing in MF mode. The mount plate is metallic, and the lens includes a USB-C port for future firmware updates. There is no weather sealing gasket under the mount plate.<\/p>\n

\"\"
Viltrox 9mm f\/2.8 Air | Metallic mounting plate with the USB-C port<\/figcaption><\/figure>\n

Autofocus is quick and snappy at normal distances, but racking from the minimum focusing distance to infinity (or vice versa) can cause the AF to hesitate, jumping once or twice before locking focus.<\/p>\n

It\u2019s worth noting that my test unit was the E-mount version used on a Z camera with an adapter, which may have contributed to some of these quirks. With a native Nikon Z mount version coming soon, adaptation shouldn\u2019t be necessary.<\/p>\n

\"\"
Viltrox 9mm f\/2.8 Air on a Nikon Zfc via a Megadap adapter<\/figcaption><\/figure>\n

Included in the box are standard front and rear caps and a hard, bayonet-style petal-shaped lens hood.<\/p>\n

\"\"
Viltrox 9mm f\/2.8 Air | caps and lens hood<\/figcaption><\/figure>\n

Optical Features<\/span><\/p>\n

\"\"
MTF curves | Viltrox 9mm f\/2.8 Air | f\/2.8<\/figcaption><\/figure>\n

Sharpness (Infinity)<\/span><\/h3>\n

For the infinity sharpness test, we look at three areas of the image, centre, mid-frame, and corner, see highlighted areas in the image below!<\/span><\/p>\n

\"\"
Infinily Sharpness Points of Inspection<\/figcaption><\/figure>\n
\"\"
Nikon Zfc | Viltrox 9mm f\/2.8 Air | f2.8<\/figcaption><\/figure>\n
\"\"
Infinity sharpness chart | Nikon Zfc | Viltrox 9mm f\/2.8 Air<\/figcaption><\/figure>\n

While performance is quite strong in the center of the image and good in the midframe, the corners are relatively weak. The lens reaches optimal across-the-frame sharpness at f\/8, with f\/11 following closely behind. Normally, Viltrox does not make different versions of the same lens formula for different mounts, so the results should be the same whether you use an adapter or not. Nevertheless, it should be noted that this test was done with the E-mount version, used via an adapter on a Z camera.<\/p>\n

Sharpness (Close-up)
\n<\/span><\/h3>\n

This Viltrox 9mm lens has an impressive minimum focusing distance of 0.13 m \u2014 though the working distance is only about 6 cm. Another positive is that sharpness is excellent even wide open at f\/2.8.<\/p>\n