Sony just started shipping their new FE 12-24mm f/2.8 GM, securing top spot for the fastest ultra wide zoom in the world!
It's also a GM lens so imagine my expectations when it came to testing and comparing it to the Sigma 14-24/2.8 DG DN Art - which is my current benchmark lens in terms of resolution and contrast for landscapes.
When my copy arrived yesterday - the first thing I noticed was how compact and light it was for a lens with a fast 12-24mm range while the build and operation felt similar to my other GM lenses. The zoom ring rotates smoothly and the focusing ring has a linear response with the perfect amount of resistance. Focus throw from MDF to infinity is ~140 degrees and focusing is snappy even in low light.
The lens' front element is guarded by a large 'pinch' type cap. It's sturdy and well designed but it's also heavy weighing 70 grams. In comparison the Sigma 14-24/2.8 Art's 'push-in' front cap weighs 30 grams and also gets the job done.
Here is a side-by-side comparison showing the FE 12-24/2.8 GM vs Sigma 14-24/2.8 DG DN with front caps:
The large extreme aspherical front elements surprisingly do not make the lens front heavy when mounted on the Sony A7R IV and the AF/MF and custom button are always very handy.
Optical design:
The Sony FE 12-24mm F2.8 GM has a complex optical design featuring 17 Elements in 14 Groups. It includes three Extreme Aspherical (XA) elements, one Aspherical, two Super ED, and three ED elements. An updated Nano AR Coating (version II) has also been applied, which from my initial flare tests is capable of suppressing flare for greater contrast in bright and backlit conditions.
Autofocus
Sony FE 12-24mm F2.8 GM features Dual XD Linear Floating Focus actuators just like those found in Sony FE 135mm F1.8 GM for extremely fast and precise focus tracking and responsive Eye AF. When not powered by a Sony camera body, one can hear the disengaged linear motor moving inside the lens. This is not a defect and in fact it's characteristic of the linear focus design.
Lens Specifications:
Focal Length 12 to 24mm (full frame)
Aperture range: f/2.8 to f/22 in third stops
Angle of View: 122° to 84°
Minimum Focus Distance: 11.02" / 28 cm
Maximum Magnification: 0.14x
Optical Design: 17 Elements in 14 Groups
Special Elements: 3 XA, 2 Super ED, 3 ED and 1 Aspherical
Software: Lightroom with FM Default Landscape Sharpening. All other settings set to default
PS: Vignetting and distortion were NOT corrected
12mm CENTER resolution/contrast comparison between Sony 12-24/2.8 GM @12mm vs Voigtlander 12mm f/5.6 III
Note: Both Voigtlander 12mm f/5.6 III M-mount and E-mount version have identical performance on the A7R IV
Center wide open: Here both lenses are wide open (Sony @2.8 and Voigtlander @5.6). The Sony GM is slightly ahead but the Voigtlander puts up a good fight at center.
Center both @f/5.6: Just like in the crop above, the Voigtlander is still wide open while the Sony performs slightly better
12mm MID-FIELD resolution/contrast comparison between Sony 12-24/2.8 GM @12mm vs Voigtlander 12mm f/5.6 III
Mid-field wide open: Here both lenses are wide open (Sony @2.8 and Voigtlander @5.6). The Sony GM perform very good wide open at mid-field at 12mm. The voigtlander lags a bit but it's not bad in comparison
Mid-field both @f/5.6: Just like in the crop above, the Voigtlander is wide open at f/5.6 and the Sony GM is optimal at f/5.6. There is a noticeable difference in resolution and contrast when both are set at f/5.6
Mid-field both @f/8: There is no improvement for the Sony and the Voigtlander improves very slightly
12mm EXTREME CORNER resolution/contrast comparison between Sony 12-24/2.8 GM @12mm vs Voigtlander 12mm f/5.6 III
Extreme corner wide open: Here both lenses are wide open (Sony @2.8 and Voigtlander @5.6). The Sony GM has decent resolution and contrast while the Voigtlander is just OK
Extreme corner both @f/5.6: Just like in the crop above, the Voigtlander is wide open at f/5.6 and the Sony GM is optimal at f/5.6. Here we can see a huge difference in resolution contrast and astigmatism between these lenses
Extreme corner both @f/8: There is no improvement for the Sony but the Voigtlander improves at f/8 (one stop down). The Sony still takes the cake at the corners but the Voigtlander is still good. it's not easy task for this tiny lens to compete.
At 14mm EXTREME CORNER resolution/contrast comparison between Sony 12-24/2.8 GM vs Sigma 14-24/2.8 DG DN Art
(14mm) Extreme Corner at f/2.8: Aside from a different color palette and higher vignetting for the Sigma, the Sony shows slightly more astigmatism wide open
(14mm) Extreme Corner at f/4: The Sony GM improves and now catches up to the Sigma
(14mm) Extreme Corner at f/5.6: Very small improvement for both lenses and they are not optimal
(14mm) Extreme Corner at f/8: Minor diffraction effect noticeable for both lenses
Thanks, Fred! This is truly the only place on the internet, where you can see such detailed real-life comparisons between lenses .
As for the test itself, it seems Sigma is particularly strong @14mm where it trades blows with the GM. Also the extreme corners look slightly better on Sigma (maybe except @18mm where Sony shines).
However, the midfield looks like an advantage to the GM, Sigma catches up only after closing down to @f5.6. Also center seems to be very slightly sharper on the GM in some cases.
To me, this tests confirms that the GM is really something unique, that other brands can only envy for now . Once I learn how to take good pictures with such ultrawides (if that ever happens), I'll reconsider getting the GM, as for me it's another system seller for Sony (but the price and performance of Sigma, makes it a difficult choice, similar to 135mm) .
Thank for the comparison, Fred! It looks like the Sigma is holding up just fine; but yes, it is not 12mm on the short end but still, 14mm is plenty wide. It looks like I am keeping my Sigma 14-24mm for the time being. I will revisit this after a year or so. I am sure you can get the GM on the used market for around $2K or so, then I may consider getting the GM.
Thanks very much Fred. I think these results are in good agreement with the reviews referred to on this page, which suggested that wide open, the corners are a little better for the Sigma below 18mm but for the Sony at longer focal lengths, and also that the Sony is a bit better midfield across the whole range.
Stopped down to 5.6, I see no reason to choose one over the other for IQ. At 12mm the Sony does look excellent though across the whole frame at 5.6. Very much looking forward to your flare tests.
Thanks for the tests! Looks like the GM and Sigma are close with the GM beating it wide open mid frame but losing a bit at the extremes. Both close though. Less vignetting on the GM.... now about the coma. I doubt the GM will win there over the sigma!
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