Sony FE 12-24mm F/4G Review

The Sony FE 12-24mm F/4G became an instant success as soon as it launched by delivering spectacular image-quality in the lightest and most compact ultra-wide angle lens for full-frame at the time. While newer lenses that cover such extremely wide angle-of-view appeared, the FE 12-24mm F/4G is still the lightest constant aperture zoom for Sony Full-Frame Mirrorless Digital Cameras.

When a lens covers at least an 84° angle-of-view, it is considered ultra-wide. On a full-frame camera, this requires an 24mm or shorter focal-length. Wider 16mm are relatively common and cover a 107° field-of-view. For more than a decade though, the exclusively wider lens was the Sigma 12-24mm F/4.5-5.6 with its incredible 122° maximum field-of-view. The Sony FE 12-24mm F/4G was launched as the first constant-aperture zoom with such extremely wide angle-of-view for mirrorless cameras, something that Sigma just managed the year before for DSLRs with the Sigma A 12-24mm F/4 DG HSM
Sigma A 12-24mm F/4 DG HSM which weighs 1.15kg. By comparison, the Sony weighs half of that at 565g!

All this context shows how special the Sony FE 12-24mm F/4G is. This lightweight full-frame lens covers a 122 - 84° field-of-view while maintaining a constant F/4 maximum aperture. This expansive field-of-view is unrivaled when capturing architecture, from enormous buildings to imposing monuments, temples and cathedrals, particularly interiors where there is no space to see a wider view. When composing sweeping vistas with close foreground elements, an ultra-wide angle is incredibly useful.

Its F/4 maximum aperture is not particularly bright but quite sufficient considering that this is a lens for Full-Frame cameras and natural subjects for its focal-range are mostly static. The depth-of-field obtained at this combination of aperture and focal-length is never shallow yet most typical subjects will require stopping down two or more steps to be entirely sharp. Remember that depth-of-field is perceptual and more stopping down is required when displaying images in larger sizes. Its 7-blade aperture can be stopped-down to F/22 which is beyond the diffraction limit of most digital cameras.

This lens has a minimal focus distance of 28cm which gives it a maximum magnification of 0.14X. A built-in motor adjusts focus internally and the lens never changes length, even while zooming. Although not entirely internal, the zoom mechanism is contained within the barrel which ends in a non-removable petal-type hood. The fixed hood and optics prevent of use of screw-on filters on this lens.

Construction

Sony gave the FE 12-24mm F/4G a streamlined design with unassuming aesthetics. The plastic barrel of this lens gets progressively wider in a series of 45° angles between cylindrical areas. The base starts with the standard 60mm E-mount diameter and the hood culminates at 87mm. Due to the fixed lens hood which is designed to protect a bulbous element, a special 92mm lens cover is necesary to encapsulate it.

Even with its relatively light weight, this lens feels quite sturdy and really well put together. There are no gaps anywhere and no flex between any component. As a professional lens, and like all but two Sony FE lenses, the Sony FE 12-24mm F/4G is fully wearherproof. Its lend hood protects the front lens element well.

Around the middle of the lens barrel, there is a wide zoom ring which rotates 45° clockwise from 12mm to 24mm. The ring has a good amount of resistance and is unlikely to accidentally rotate. Immediately after towards the front of the lens, there is a nicely sized fly-by-wire focus-ring. It turns smoothly and indefinitely without stops. Since this is a fly-by-wire ring, the camera is free to decide when to react. A switch near the base of the lens barrel selects between AF and MF mode. Sony cameras currently allow manul-focus when the switch is set to MF or when the camera is set to DMF and only right after autofocus is acheived. This means that when the camera is unable to focus, the switch must be set to MF to allow manual focusing.

An unmarked button on the side of the lens can be used as an additional customizable function button by most Sony mirrorless digital cameras. The button is springly with a positive audible click confirming it was pressed. Its position is easy to reach without letting go of the zoom ring. There is no image-stabilization button on this lens is unnecessary on nearly all Sony mirrorless which offer superior built-in image-stabilization which is virtually impossible to match inside a lens.

Sony FE 12-24mm F/4G Sharpness

Ultra-wide lenses are the most challenging to design optically and so they frequently show more optical defects than any other type of lens. The expansive field-of-view makes it extremely difficult to render details consistently across the entire imaging circle. The most critical aspect of performance is sharpness, so we are happy to report that the Sony FE 12-24mm F/4G manages to exceed expectations with a truly impressive performance.

Center sharpness is perfect both at its widest and least-wide focal-length. It gets somewhat soft wide-open near the middle of the zoom but stopping down 2 stops to F/8 corrects this quite well. Corners are visible soft wide-open at extreme wide-angle and slightly soft when zoomed in. Stopping down improves things very quickly with only one stop needed to get critical sharpness at any focal-length except 12mm. To get sharp output then, it is necessary to close the aperture down an extra stop.

Shown below are 5 crops taken from a photograph, repeatedly captured for each combination of focal-length and aperture. Smaller pieces are cropped from extreme corners of the images, while the middle wide crop is taken from the center of images. Select an aperture in a row for a desired focal-length to see the crops from the corresponding image. When judging image quality, understand that these are crops from a 61 MP image which is normally used to print images up to 45x30". On a computer display, these may appear much larger which magnifies image defects.

Performance

This extremely wide-angle lens shows virtually no distortion across its zoom range. A barely measurable amount of barrel distortion can be detected around the middle of the zoom but lines look completely straight. Given that the Sony FE 12-24mm F/4G is expected to be used for architecture more than any other subject, rendering straight lines is one of the most important aspects of this lens.

Ultra-wide-angle lenses often show undesirable vignetting and the FE 12-24mm F/4G is unfortunately no exception. Started at the widest 12mm focal-length there is a whopping 3½-stops of vignetting at the maximum aperture of F/4. Stopping the lens down barely diminishes vignetting which never goes lower than2½-stops. Around 18mm, there is 2¼-stops at F/4 but stopping down produces better results, improving by ½-stops at F/5.6 and again at F/8. This still leaves over 1¼-stops of light loss at extreme corners of images. At the longest focal-length, which is still ultra-wide, vignetting starts just above 1½-stops which finally dips below 1-stop at F/8.

The good news is that modern Sony digital cameras feature built-in software correction for vignetting which is fairly effective yet never comes close to completely eliminating the issue. A Sony A7R IV reviewed here
Sony Alpha A7R IV manages to lower vignetting by between 1 and 1½-stops, depending on the combination of focal-length and aperture. This leaves almost 2-stops of darkening at 12mm F/4 and still over 1-stop at smaller apertures. Starting near the middle of the zoom range, vignetting compensation leaves about a stop of light loss regardless of the selected aperture. There is only 1/8-stop difference between 18 and 24mm.

Although vignetting is apparent in all photographs captured by the Sony FE 12-24mm F/.4G, this is the easiest and least destructive defect to correct via image processing. This is certainly a deliberate choice from Sony to limit amount of glass required for such an extremely wide lens. Adobe Lightroom and most other photo editing software have tools which make this easy to correct.

A minimal yet constant level of chromatic aberrations is visible along high-contrast edges. The aberration is very light towards magenta and is rather easy to correct using modern image processing software. Even if left uncorrected, the issue is virtually impossible to notice in anything but the largest prints. Optical elements of the FE 12-24mm F/4G are covered with state-of-the-art coatings which make this lens incredibly resistant to flare. When capturing wide city-scapes and architectural images at night, this is truly fantastic.

Autofocus performance of this lens is excellent. The lightweight internal focusing system inside the FE 12-24mm F/4G allows it to focus extremely quickly and nearly silently even in moderately low-light.When focusing stopped down, which is possibly the default on most Sony mirrorless, there is much less light and so the lens necesarily needs more time to focus. Above mid-range apertures though, autofocus is always fast.

Conclusion

After reading this review, it is unsurprising that the Sony FE 12-24mm F/4G is one of the most extraordinary lenses every produced. It provides a rare extremely wide angle-of-view with a moderate constant aperture in an incredibly light yet durable weatherproof body. Everything about this lens is deliberate as it manages to deliver high image-quality limited by constraints to realize its uniquely compact design.

Sharpness is really good and even quite uniform when stopped down to F/8. At larger apertures, the center is tack sharp at both ends of its focal-range but shows moderate softness around the middle. Corners are always noticeable softer than the center but the difference becomes much smaller at F/5.6 or smaller apertures. The visible sharpness depends on display size and so images can look perfectly sharp corner-to-corner when in small to medium prints for most combinations of focal-length and apertures.

The Sony FE 12-24mm F/4G is ideal for capturing architecture and landscapes for travel photographers. Its combination of extreme angle-of-view and compact size is unrivaled. This lens particularly excels at interiors where space is limited by capturing an expansive field-of-view while preserving the straight lines formed by walls and columns among other things. For a Sony Full-Frame system, the FE 12-24mm F/4G is essential unless your budget and back can handle the FE 12-24mm F/2.8 GM reviewed on the next page.