Viltrox Air AF 90mm F3.5 90mm

The Viltrox Air AF 90mm F3.5 weighs just 170g and delivers 86th percentile autofocus for DJI's DL mount. Build quality is excellent at the 88th percentile, but optics are middling at the 51st. At $499 USD, it's a practical telephoto for Inspire 3 and Ronin 4D shooters who value portability over pixel perfection.

Autofocus is the headline here. The STM motor with lead screw drive puts this lens in the 86th percentile for AF speed and accuracy, which is impressive for a third-party aerial lens. DJI's DL mount system isn't exactly drowning in options, so having a lens that locks focus quickly and smoothly on the Inspire 3's 8K sensor is a real advantage. The internal focus design keeps the barrel from extending, which matters when your lens is strapped to a drone and every gram of balance counts.

Optically, it's a mixed bag. The 12 elements in 9 groups do a decent job controlling chromatic aberration, but the 51st percentile optical score tells you this isn't a benchmark crusher. The f/3.5 aperture is fine for a telephoto prime, though it ranks in the 44th percentile, meaning most lenses in our database open wider. Bokeh sits at the 39th percentile, so don't expect creamy background separation. The 9-blade diaphragm helps keep highlights round, but at f/3.5 on a 90mm, you're not getting shallow depth of field magic. Minimum focus distance of 800mm and 0.114x magnification put macro capability in the 28th percentile, which is a polite way of saying this lens doesn't do close-up work.

Comparing this to the Sigma 18-50mm f/2.8 or Tamron 17-70mm f/2.8 is a bit unfair since those are zoom lenses for completely different mounts. But it does highlight what you're giving up. The Sigma and Tamron both open to f/2.8, a full stop faster than the Viltrox's f/3.5, and they offer zoom flexibility. The Panasonic Leica 12-35mm and Nikon 18-140mm similarly give you range and speed. What none of them offer is DL mount compatibility or 170g weight with full-frame coverage. The Viltrox wins on portability and native integration, but loses on optical versatility. The Sony 18-135mm f/3.5-5.6 is probably the closest in spirit, a compact telephoto option, but again, wrong mount. If you're in the DJI system, this comparison section is almost moot. You buy this lens because it fits your camera, not because it beats a Sigma on a test chart.

At $499 USD, this lens is aggressively priced for the DL mount system. DJI's own DL lenses cost significantly more, and third-party options are scarce. The EUR listings range from 580 to 593, and Canadian buyers are looking at 698 CAD. For a lens that delivers 86th percentile autofocus and 88th percentile build quality, that's a solid deal. The catch is that you're paying for integration and convenience more than optical excellence. If this were a Sony E-mount lens at this price, the 51st percentile optics would be harder to swallow. But in the DL mount world, where your alternatives are limited and expensive, the value proposition is much stronger.

The Viltrox Air AF 90mm F3.5 is a weird little lens, and we mean that as a compliment. It weighs 170g, which is lighter than most smartphones with a case, yet it covers a full-frame sensor and promises 8K clarity for DJI's Inspire 3 and Ronin 4D. That's a niche within a niche, but if you're flying an X9-8K gimbal, this is one of the only autofocus telephoto primes you can actually buy for the DL mount.

The numbers tell an interesting story. Build quality lands in the 88th percentile, autofocus in the 86th, and stabilization in the 82nd. Those are genuinely strong scores for a lens this small and this affordable. But optical performance sits at the 51st percentile, and aperture at the 44th. So you're getting a well-built, fast-focusing lens with middling glass and a slow-ish f/3.5 maximum aperture. Whether that trade-off works depends entirely on what you're shooting.

Skip this lens if you're not already in the DJI DL mount system. There's no adapter path to other systems, so it's a paperweight on anything but an Inspire 3, Ronin 4D, or X9-8K gimbal. Also skip it if you need shallow depth of field. The f/3.5 aperture and 39th percentile bokeh mean you won't get that creamy background separation telephoto primes are known for. And if you shoot in wet or dusty conditions, the lack of weather sealing is a real concern for a lens designed to fly outdoors. The 28th percentile macro score also rules out anyone hoping to use this for product or detail work.

The Viltrox Air AF 90mm F3.5 is a specialist's lens. If you fly an Inspire 3 or shoot on a Ronin 4D and need a lightweight telephoto prime with reliable autofocus, this is an easy recommendation at $499 USD. The 170g weight and 86th percentile AF performance make it genuinely useful for aerial work where every gram matters. But if you're expecting optical brilliance, you'll be underwhelmed. The 51st percentile optics and f/3.5 aperture mean this lens is about practicality, not pixel-peeping perfection. For the right user, it's a no-brainer. For everyone else, it's a curiosity.