Viltrox AF 27mm f/ 1.2 Pro lens review

Astrophotography is most commonly shot using full-frame cameras but, despite their smaller sensors, APS-C cameras are just as effective. With much improved noise handling over previous generations, modern APS-C cameras often offer a lighter weight and more compact alternative. This can be incredibly useful when shooting in locations that require trekking to reach.

The same goes for lenses, which are also typically smaller and lighter, and the Viltrox AF 27mm f/ 1.2 Pro lens, with its 40.5mm equivalent focal length, is much more compact than a 35mm f/1.2 full-frame lens. Plus, whether you’re on a budget or not, you’ll be pleased to hear that it costs just $578 / £530, making it an incredibly inexpensive lens considering the specs on offer. Later, I’ll delve into build and image quality further.

This 27mm APS-C lens is available in Fujifilm X, Nikon Z (APS-C) and Sony E mounts and provides an equivalent focal length of 40.5mm. For the review, I tested the lens with a full-frame Sony camera set to crop mode, so the performance of the lens was identical to a Sony E-Mount camera.

The 27mm f/ 1.2 Pro is perfect for astrophotography, landscape, cityscape, street and portraiture, so it’s a highly versatile all-rounder that will undoubtedly see plenty of use. For astrophotography, 35-40mm is a great focal length for incorporating more prominent foreground interest into shots. So, pair this lens with one of the best cameras for astrophotography (there are some APS-C options on the list) and you could potentially be looking at a match made in heaven.

Viltrox AF 27mm f/ 1.2 Pro lens review

Viltrox AF 27mm f/ 1.2 Pro: Design

• Compact for an f/1.2 lens
• Excellent build quality
• Weather sealed

APS-C lenses are smaller and lighter than their full-frame counterparts and the 27mm f/ 1.2 Pro is no exception. This is despite the extremely generous f/1.2 maximum aperture that’s perfect for capturing the night sky. f/1.2 lenses are typically large so it’s impressive to see one that manages to remain fairly compact. It is, however, much larger than slower f/1.8 APS-C prime lenses.

The lens is quite stumpy, you could say, with a maximum height and length that are almost the same. The tall front section of the lens, with its 67mm filter thread, is the result of the fast maximum aperture, but it still isn’t cumbersome at all.

The 27mm f/ 1.2 Pro is 3.23 x 3.62 in / 82 x 92mm with a weight of 19.93 oz / 565 g, so it balances well with Fujifilm, Nikon and Sony APS-C mirrorless cameras. As the ‘Pro’ moniker suggests, build quality is excellent with a full metal body. Plus, the lens is weather sealed, so it’s perfect for professional outdoor use, including astrophotography.

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The lens feels solid and the unassuming black design will blend well with any of the cameras the lens is compatible with. It features a wide manual focusing ring that can be easily used when wearing gloves. The manual aperture ring is also suitably wide and grippy for gloved operation, with the ability to be set to clicked or clickless operation. The latter is ideal for video capture, where a stepless aperture is often preferred.

When it comes to controls, there’s an AF/MF switch, a focus lock button and a click switch for the manual aperture ring. This is a slightly more basic design than the full-frame PRO and LAB Viltrox lenses, but in terms of prime lenses in general, the 27mm f/ 1.2 Pro offers no more or less than the competition in terms of controls. On the lens mount, there’s a USB-C port for firmware updates, which is great for a third-party lens that can’t be updated through the camera menu.

Viltrox AF 27mm f/ 1.2 Pro: Functionality

• No optical image stabilization
• Fast and silent autofocus
• Short minimum focus

The AF 27mm f/ 1.2 Pro is a fairly standard prime lens in terms of functionality, with the main selling points being excellent image quality alongside a fast maximum aperture. This is a hybrid lens that can be used for both photography and video, with the clickless aperture being ideal for video. For stills photography, including astrophotography, the clicked aperture option is more appropriate.

Autofocus is fast, silent and accurate thanks to the stepping motor, which is useful for both photography and video, although manual focus is used by both astrophotographers and videographers because it’s more reliable in these situations. The manual focus ring provides a comfortable amount of resistance that allows for fast and precise manual focus.

As is often the case with prime lenses, the 27mm f/1.2 Pro doesn’t feature optical image stabilization, so no surprises here. But if your camera has In-camera Image Stabilization (IBIS), you can still take advantage of this feature, albeit not through the lens itself. This is best left switched off when shooting with the camera attached to a tripod.

Despite being an APS-C lens, the 27mm f/1.2 Pro can still be used with Sony FE and Nikon Z-mount series full-frame cameras since these two lens mounts include APS-C and full-frame cameras. To use APS-C lenses with full-frame cameras, you simply have to set the cameras to crop mode so that less of the sensor is used to meet the APS-C format.

In reality, you would never buy this lens specifically to use on a full-frame camera. You might, however, use it on a full-frame camera if you have both APS-C and full-frame bodies. For APS-C camera owners, it’s a fantastic combination of focal length and maximum aperture.

Viltrox AF 27mm f/ 1.2 Pro: Performance

• Excellent image quality
• Impressive sharpness at f/1.2
• Suitable for photography and video

The front element of the lens features a water and smudge-resistant coating. This is handy for outdoor shooting, of course, but it’s always best not to touch the front element or allow rain droplets to hit it where possible. The included lens hood offers a degree of protection alongside helping to reduce flare and haze.

The 27mm f/ 1.2 Pro is made up of 15 elements in 11 groups including two ED, five elements with a high refractive index and one aspherical lens. There’s also Viltrox’s HD Nano multi-layer coating to minimize ghosting and flare.

The 27mm f/ 1.2 Pro produces exquisite sharpness even wide open at f/1.2. Levels of sharpness are impressively high across the frame, even in the corners, making it a truly stunning lens.

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All apertures produce impressively sharp images with excellent corner sharpness, although at f/16 diffraction does come into play to produce the least sharp result of all apertures. f/8 is the sweet spot that resolves the sharpest detail, but for astrophotographers, it’s the impressive performance at f/1.2 that will be of most interest.

Vignetting is strong wide open at f/1.2, but Adobe Lightroom Lens Profiles take care of this and the tiny amount of barrel distortion that’s present. The latter is minimal and barely visible to the naked eye. Vignetting is all but gone at f/2.8, although the fact that Lens Corrections removes the strong vignetting at f/1.2 is most important.

The minimum focusing distance is short at 11 in / 28 cm, which is useful for general photography but not so much for astrophotography. It’s handy to have if you need it, so no complaints. The aperture is made up of 11 blades, making it circular, so bokeh highlights are also circular, although once again, this isn’t relevant to astrophotography since distant stars are the point of focus rather than close-up subjects.

Viltrox AF 27mm f/ 1.2 Pro: Price

Lenses with an f/1.2 maximum aperture are typically expensive. Even those with an f/1.4 maximum aperture command a typically hefty price tag, but the Viltrox AF 27mm f/ 1.2 Pro bucks this trend to deliver some incredible value for money. At just $578 / £530, this well-made lens with a useful equivalent focal length of 40.5mm is a bargain.

In reality, there aren’t any direct alternatives available, so this is a lens that stands alone. In the box, you get the lens, a lens hood, front and rear lens caps and a soft lens pouch. This is the standard for most lenses, and many photographers will store their lenses directly in their camera bags rather than a lens pouch.

Viltrox AF 27mm f/ 1.2 Pro: User reviews

Online reviews for this lens agree that the Viltrox AF 27mm f/ 1.2 Pro is an extremely well made lens with excellent sharpness overall and in particular at f/1.2. They also comment that autofocus is fast and reliable, while the lens is available at an excellent price.

How we tested the Viltrox AF 27mm f/ 1.2 Pro

The Viltrox AF 27mm f/ 1.2 Pro was tested in combination with the Sony A7R III, which offers a high resolution which is reduced to 18MP in crop mode for APS-C lens compatibility. The lens was tested at night with a focus on astrophotography, and in daylight to assess sharpness, distortion and general functionality.

Should you buy the Viltrox AF 27mm f/ 1.2 Pro?

If you shoot with a Fujifilm X, Nikon Z or Sony E-Mount APS-C cameras, the Viltrox AF 27mm f/ 1.2 Pro is a fantastic lens offering a 40.5mm equivalent focal length. This is pretty close to the useful full-frame 35mm focal length. What’s more, the ultra-fast f/1.2 maximum aperture is a boon for astrophotographers.

The lens is also designed for both photo and video capture, so it has huge scope for use alongside being suitable for a range of subjects. With excellent build quality, great image quality and a highly cost-effective price, this is a lens well worth considering for capturing the night sky.

If this lens isn't for you

The Sigma 14mm F1.4 DG DN HSM ART is an incredibly fast and wide full-frame lens with an APS-equivalent focal length of 21mm. This could be perfect if you’re looking for a fast, wide-angle prime.

The Sigma 20mm f/1.4 DG HSM ART is an APS-C prime offering an equivalent focal length of 30mm alongside a compact and lightweight build at an affordable price for Sony E-Mount cameras.

The Sony 20mm f/1.8 G is a stunning full-frame wide-angle prime that produces a 30mm equivalent focal length when used with APS-C cameras. It also provides longevity if you plan to upgrade to full-frame in the future.

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