In summary
Most photographers will find the FE 24-70mm f/2.8 GM lens to be a versatile ‘walkaround’ lens that is a good match for Sony’s α7 ‘full frame’ camera bodies. Its wide maximum aperture makes it ideal for low light use and also for isolating subjects from distracting backgrounds. But it also makes this lens relatively expensive.
With apertures selectable from f/2.8 to f/22, there’s plenty of scope for differential focusing and experimenting with selective focus control. However, the edge softness we detected may make it unsuitable for landscape and architectural photographers who require shots to be sharp corner-to-corner.
Full review
Sony’s new FE 24-70mm f/2.8 GM (model SEL2470GM) lens is one of three G-Master lenses that were announced in February 2016 and are now becoming available in stores. A key feature of this lens is the constant f/2.8 maximum aperture throughout the zoom range. According to Sony, this has been achieved through advanced lens technologies and a no-compromise design that includes dust and moisture resistant construction.
Sony’s new FE 24-70mm f/2.8 G-Master lens, shown without the supplied lens hood. (Source: Sony.)
We reviewed the first G Master lens to be released, the FE 85mm f/1.4 GM (model SEL85F14GM), in April 2016 and look forward to testing the FE 70-200mm F2.8 GM OSS lens when it becomes available. We also reviewed Sony’s other 24-70mm lens, the Zeiss-branded Vario-Tessar T* FE 24-70mm f/4 ZA OSS lens, which is as solidly built but a stop slower.
Appropriately for such a fast lens, the FE 24-70mm f/2.8 GM lens has a complex optical design that encompasses 18 elements in 13 groups and includes some exotic glass. There are three aspherical elements including a newly developed XA (extreme aspherical) element that reduces aberration and delivers high resolution throughout the entire zoom range and aperture range and from corner to corner of image files. An ED (Extra-low-Dispersion) glass element and Super ED glass element control chromatic aberration while maximizing resolution and bokeh.
Sony’s Advanced Nano AR Coating has been applied to individual elements to minimise flare and ghosting. The iris diaphragm (which controls lens apertures) has nine blades, which close to produce a smooth circular aperture that delivers smooth rendering of out-of-focus areas in scenes.
Autofocusing is driven by a piezoelectric direct drive SSM (super-sonic motor) system which includes a new set of algorithms that position the lens elements quickly and accurately. All focusing is internal so the front element doesn’t rotate during focusing and zooming.
The lens is supplied with the usual front and end caps plus a cylindrical lens hood and a smart, semi-rigid carrying pouch with a shoulder strap and zip closures. The metal hood is solidly built and attaches via a bayonet mount with a locking mechanism that keeps it in place but makes it easy to remove when required. It can be reversed over the lens for transport and storage.
Also provided is a set of multi-lingual printed sheets with diagrams, operating instructions and specifications. Among them is one pertaining to customers in the USA, Canada and ‘countries applying EU directives’, which lays out some sensible advice for using and cleaning the lens.
Who’s it For?
Although it can be used on cameras with APS-C sized sensors, essentially, this lens is designed for Sony’s ‘full frame’ α7 cameras, where it spans angles of view between moderate wide-angle and short telephoto. This makes it a versatile choice for everyday photography and suitable as a general-purpose ‘walk-around’ lens for travelling photographers.
The constant, fast f/2.8 maximum aperture makes it ideal for working in low-light conditions and with selective focus control. The same characteristics would make it suitable for event photography, particularly capturing groups of people. Wider angles of view could also be used for landscape photography.
Build and Ergonomics
As expected for its price, the build quality is very good and, although it’s not listed in the specifications we suspect most of the lens barrel is made from metal. The mounting plate is metal and very solid.
Like the 85mm GM lens, this lens is dust and moisture resistant, which enables it to be used in challenging environments and makes it an ideal partner to camera bodies that have similar characteristics. Unlike the Vario-Tessar T* FE 24-70mm f/4 ZA OSS lens, this lens is not stabilisation and relies upon the Steadyshot Inside technology in Sony’s α7 cameras.
The focusing ring is located at the front of the outer barrel. It’s 23 mm wide with the 20 mm at the leading edge clad with a finely-ribbed rubber grip band. Focusing is electronically controlled and driven by a piezoelectric direct drive SSM. It’s well implemented and supports fast autofocusing but doesn’t provide much tactile feedback.
An almost identical ribbing also covers most of the zoom ring, which begins 18 mm behind the focusing ring. It is roughly 33 mm wide and has an un-ridged trailing edge that carries indicator marks for the 24mm, 35mm, 50m and 70mm focal lengths.
These line up against a white mark on the non-moving section of the lens barrel. The rotary zoom mechanism extends the lens by 28 mm when moving from the 24mm to the 70mm position. A zoom lock is located to the right of the 70mm position.
Behind the zoom ring the lens barrel remains straight for 20 mm before stepping inwards for the final 15 mm that leads to the lens mount. The AF/MF slider is located here.The characteristic cinnabar-coloured ring surrounds the barrel just in front of the mounting point.
The minimum focusing distance is only 38 cm, which isn’t ideal for close-up shooting. However, the f/2.8 maximum aperture at 70mm provided plenty of scope for isolating subjects from the background.
Performance
We carried out or tests with the lens on the α7R Mark II body, which was likely to show up any evidence of poor performance because of its high-resolution sensor. It being winter in Australia and given the speed of this lens, we captured most of our test shots at a night market just after sunset with the camera’s ISO set on auto and using the P shooting mode. (It was interesting to see how often the camera chose the maximum lens aperture in this situation.)
Subjective assessment of JPEGs straight out of the camera showed they looked lively and detailed, regardless of whether they were taken in bright, sunny conditions or after dark. With flatter lighting, the more subdued colour saturation indicated by our Imatest tests became evident, although overall sharpness was maintained in the centre of image frames.
Although autofocusing speed is largely dictated by the camera and the selected focusing mode, we found the lens was very quick to focus on the α7RM2 in single AF mode and able to keep pace with moving subjects when continuous AF was selected. There were no instances of hunting and no missed shots during our tests.
Imatest showed this lens to be capable of meeting expectations for the 42-megapixel sensor on the α7R Mark II, even with JPEG files. However, this only occurred across a limited range of aperture settings with the 50mm and 70mm focal lengths and only in the centre of the frame. The edges of the frame remained soft at all focal lengths and apertures. The graph below shows the Imatest results for the aperture ranges for each focal length setting.
Lateral chromatic aberration was generally at the low end of the ‘negligible’ band in both auto-corrected JPEGs and uncorrected ARW.RAW files and, thus, won’t be a problem for this lens. The results of our Imatest tests are shown in the graph below.
Like other Sony lenses, this lens has been designed for use with cameras that provide automatic corrections for rectilinear distortions, vignetting and chromatic aberration. While you can turn off these corrections in the α7R Mark II, we shot both JPEG and raw files to assess performance in these areas and found the following:
Distortion not corrected in the camera is significant and ranges from obvious barrel distortion at 24mm to barely detectable pincushion distortion at 70mm with very little evidence of distortion between these extremes. With auto-corrected JPEGs, no distortion can be seen.
Vignetting not corrected in the camera produced noticeable corner darkening at f/1.4 for all focal length settings. It was most visible at 24mm and reduced progressively for longer focal lengths becoming relatively slight at 70mm. With auto-corrected JPEGs, vignetting is effectively negligible.
Flare resistance was generally excellent, particularly at longer focal lengths, thanks to the well-designed lens hood and effective anti-reflection coatings. We found some flaring with the 24mm focal length when a bright light source was just outside the image frame. Flare artefacts also occurred with the 35mm and 50mm focal lengths in the same shooting conditions but not at 70mm.
Bokeh was somewhat variable and smoother when shots were taken in relatively flat lighting. Bright highlights showed a slight tendency to show outlining, regardless of the lighting conditions. Tonal transitions in shots taken in contrasty lighting weren’t quite as smooth as most photographers would wish for with such an expensive lens.
Conclusion
Most photographers will find the FE 24-70mm f/2.8 GM lens to be a versatile ‘walkaround’ lens that is a good match for Sony’s α7 ‘full frame’ camera bodies. Its wide maximum aperture makes it ideal for low light use and also for isolating subjects from distracting backgrounds. But it also makes this lens relatively expensive.
With apertures selectable from f/2.8 to f/22, there’s plenty of scope for differential focusing and experimenting with selective focus control. However, the edge softness we detected may make it unsuitable for landscape and architectural photographers who require shots to be sharp corner-to-corner.
Photographers considering this lens will need to decide whether it’s worth paying roughly AU$2000 extra for a one-stop advantage over the Vario-Tessar T* FE 24-70mm f/4 ZA OSS lens we reviewed in July 2014, which was also a superior performer. Shopping around will save you money on both these lenses, although buying off-shore is unlikely to recoup enough to cover shipping and insurance costs plus the mandatory GST applied to purchases valued at over $1000.
SPECS
Picture angle: 84 to 34 degrees (35mm format); 61 to 23 degrees (APS-C sensor)
Minimum aperture: f/22
Lens construction: 18 elements in 13 groups (including one XA, one ED and one Super ED glass lens element)
Lens mounts: Sony E-mount
Diaphragm Blades: 9 (circular aperture)
Focus drive: Direct drive Super Sonic Wave Motor (DDSSM)
Stabilisation: No (Sony Alpha cameras include sensor-shift stabilisation)
Minimum focus: 38 cm
Maximum magnification: 0.24x
Filter size: 82 mm
Dimensions (Diameter x L): 87.6 x 136 mm
Weight: 886 grams
Standard Accessories: Lens hood (ALC-SH141), front cap (ALC-F82S), rear cap (ALC-R1EM), case, printed documentation.
TESTS
Based upon JPEG files taken with the Sony α7R Mark II camera.
SAMPLES
Vignetting at f/2.8, 24mm focal length.
Vignetting at f/2.8, 35mm focal length.
Vignetting at f/2.8, 50mm focal length.
Vignetting at f/2.8, 70mm focal length.
Rectilinear distortion at 24mm.
Rectilinear distortion at 35mm.
Rectilinear distortion at 50mm.
Rectilinear distortion at 70mm.
24mm focal length, ISO 100, 1/320 second at f/8.
35mm focal length, ISO 100, 1/500 second at f/8.
50mm focal length, ISO 100, 1/500 second at f/8.
70mm focal length, ISO 100, 1/400 second at f/8.
Close-up in low-contrast lighting; 24mm focal length, ISO 100, 1/500 second at f/2.8.
Close-up in contrasty lighting; 24mm focal length, ISO 100, 1/3200 second at f/3.5.
Close-up in contrasty lighting; 70mm focal length, ISO 100, 1/1000 second at f/3.5.
Flare at 24mm focal length; ISO 100, 1/1000 second at f/8.
Flare artefacts (circled) at 35mm focal length; ISO 100, 1/640 second at f/8.
24mm focal length; ISO 400, 1/100 second at f/5.6.
62mm focal length; ISO 250, 1/80 second at f/2.8.
43mm focal length; ISO 400, 1/60 second at f/2.8.
65mm focal length; ISO 2500, 1/80 second at f/2.8.
60mm focal length; ISO 1000, 1/60 second at f/3.5.
56mm focal length; ISO 1000, 1/25 second at f/4.
70mm focal length; ISO 800, 1/80 second at f/2.8.
57mm focal length; ISO 1250, 1/30 second at f/3.5.
24mm focal length; ISO 3200, 1/60 second at f/5.6.
70mm focal length; ISO 6400, 1/80 second at f/5.6.
70mm focal length; ISO 6400, 1/80 second at f/5.
Rating
RRP: AU$3499; US$2200
- Build: 9.0
- Handling: 8.8
- Image quality: 8.9
- Versatility: 8.8