The classic 50mm prime lens takes many different forms across every camera system in existence. Sony alone has a handful of 50s in their range, from the entry-level to the outstanding Planar T* 50mm f1.4 ZA. But nothing out of the six or so standard primes have had the privilege to bear the G Master badge, until the release of the Sony GM 50mm f1.2.
The GM badge brings with it a promise of pro-level reliability and optical excellence that is in a league of its own. So, with Sony taking almost a decade to come up with an f1.2 lens, there are a lot of questions floating around and some mighty high expectations waiting to be met.
With the aforementioned ZEISS T* 50mm f1.4 already serving Sony’s pro-level segment, can the Sony GM 50mm f1.2 justify the step up, especially with a $500 difference? Is the fastest, 50mm f1.2 prime for the FE system worth the wait? Let’s have a look at what the pros are saying.
Build Quality and Handling
While it’s in no way a pancake lens, the Sony FE 50mm f/1.2 GM is still a relatively compact lens for what it is. Put the Canon and Nikon’s top-tier 50mm prime offerings side by side with the Sony GM, and you’ll quickly see a glaring difference in the dimensions. The Sony 50mm f1.2 G Master, weighing 778 grams, is still around 170 grams lighter then the Canon RF 50mm f1.2. Put in on the scales against the massive Nikkor Z 50mm f1.2 and you’ll see a 300-gram weight difference. And yup, even smaller than the Panasonic S Pro 50mm f1.4 for the L-Mount system. Combine it with one of Sony’s smaller full frame cameras, you got a pretty good sized kit you can throw in a small camera bag and take anywhere.
While the Canon is marginally shorter than the Sony, the Sony still manages to be the skinnier lens at only 3.4 x 4.3 inches. For long time Sony shooters, a better way of putting it into perspective is that Sony has come up with a 50mm prime that goes all the way down to f1.2, while not being any larger than the Sony ZEISS T* 50mm f1.4 it dethrones as the top-end option.
Being a GM lens, you can expect the Sony 50mm f1.2 to perform in harsh weather conditions thanks to all the internal seals that keep it safe against dust and water splashes. It is indeed made up of polycarbonate — some would say posh plastic — but it’s got a reassuring sturdiness to it.
The focus racking action has a linear response, which means it’s repeatable, and a must for video use where you’ll often need to rack your focus with every shot. The aperture ring can be adjusted in three-stop increments or enter a “de-clicked” mode via a handy toggle switch for smoother aperture transitions, which again is a boon for videographers. Finally, you’ll also be getting two programmable function buttons, each located conveniently within reach as you hold the camera either vertically or horizontally.
In his written review, journalist and photographer Matthew Richard says:
“Build quality feels of a fully professional-grade standard, with a robust construction that features comprehensive weather-seals… Handling enhancements include two function buttons that fall naturally under the thumb in both landscape and portrait orientation shooting.”
Image Quality
We first touched on the Sony GM 50mm f1.2 in our round up of the best Sony Full Frame (FE) Lenses, and on there, we found Sony’s fastest lens to date exhibiting out of this world sharpness at f1.2. LensTip, as always, provides in-depth lab test results that back up this claim, and you should really check the data out if you’re considering getting the Sony 50mm f1.2 GM yourself.
It’s so sharp wide open that it outresolves the stopped-down, peak sharpness of 50mm primes like the Sony FE 50mm f1.8 and the Zeiss 55mm f1.8, reaching an incredible 69.7 lpmm (line pairs per millimeter). Peak sharpness is achieved when stopped down to f4, reaching 79.0 lpmm.
For a little context, 79.0 lpmm barely misses the mark at setting a new peak-sharpness record, where the Sigma 65mm f/2 DG DN holds the top peak-sharpness of 82.7 lpmm in LensTip’s database. However, LensTip does acknowledge that perhaps the design team poured most of their focus on making it perform extremely well wide open instead of aiming for better peak sharpness.
Corner sharpness is no slouch, either. Wide open, the Sony 50mm f1.2 GM resolves 44 lpmm and then peaks at 63 lpmm, which again, are very good figures. Gerald Undone has done his own testing of this phenomenal lens at different apertures and against the Sigma 24-70 f2.8, and his results coincide perfectly with LensTip’s lab results:
“To just give you an idea of how sharp we’re talking about here… This lens performs approximately at f1.2 like the Sigma 24-70 performs at f2.8. That’s impressive.”
Ted Forbes notes that he had to try really hard to get any hint of chromatic aberration. And even then, the level of chromatic aberration is very subdued and can be easily fixed in post.
“The rendering on this lens is absolutely gorgeous. Edge to edge sharpness is very impressive. Vignetting is really well controlled. And chromatic aberration. Well, I had to try to get it. You can get it, and honestly it was not easy.”
Because you’re buying an f1.2 lens, you’re probably going to spending a lot of time shooting it wide open. So it better have a beautiful look to it, as well as perfectly smooth out of focus elements. Fortunately, the long wait for the first native FE f1.2 lens seems to be worth it.
Unlike the 50mm f1.4 ZA, the newer Sony GM 50mm f1.2 does not exhibit the same onion skinning on spherical highlights, and produces clean, rounded bokeh balls without the green fringing present in the Zeiss.
“But the ZA 50mm was a favorite lens of mine. The rendering would give you these beautiful circular textures, but it was never really distracting. It just really looked good, and the good news is that it actually carries over to the G Master version… and it’s also 1/3 stops faster. You don’t lose any of the rendering but you do clean up some of the issues which is a big plus.”
AF Performance
If you’ve been around long enough to know that f1.2 lenses are downright slow and awful at hitting critical focus, you’re probably having a tough time thinking about sinking $2,000 on another f1.2 glass. However, know that the Sony GM 50mm f1.2 is born of new tech, and is reportedly the fastest autofocusing 50mm f1.2 out there.
The 50mm f1.2 GM is driven by what Sony calls “XD Linear Motors” that seem to be packing enough power to move the prime’s chunky elements around very quickly and quietly. Check out Dan Watson’s real time, continuous autofocus test run to see how snappy the AF is on this thing and how it tracks the subject flawlessly for both photo and video mode:
“You can definitely tell the difference between linear moving autofocus motors, especially with two separate groups, it’s moving twice as fast than most of the rotational style autofocus systems like the Canon 50mm f1.2. This is definitely going to be a better system, noticeably faster, and just much better.”
However, it’s in the autofocusing department where we uncover the 50mm f1.2 GM’s Achilles’ heel. This premium 50mm prime for the FE system exhibits some pretty significant focus breathing. For those not in the know, focus breathing is when a lens pulls back a little as you rack focus and have a bit of change in the field of view. For serious video work, a lot of focus breathing can be seriously distracting, and can be a deal breaker for some.
DPReview has a handy demonstration of the level of focus breathing on the Sony 50mm f1.2 GM if you’re curious:
Sony FE 50mm f/1.2 vs Sony ZA 50mm f1.4 vs Sigma 50mm f/1.4 DG HSM Art
The newest addition to Sony’s G Master line doesn’t exist in a vacuum. The closest contender to the GM is of course Sony’s very own ZA 50mm f1.4, which Ted Forbes, a fan of the classic standard focal length, claimed to be his favorite 50mm prime for the Sony system until the GM came along.
Julia Trotti even pitted the Zeiss and the GM 50mm primes against each other, and while she found the GM to be the objectively better lens overall, the Zeiss is still more than good enough for the type of portrait work she does, and therefore will not be making the switch.
There’s a $500 difference between the two heavyweights, and is of course a major consideration for anyone wanting a top-end 50mm prime. But there’s another alternative for a high-end 50mm prime if you’re not willing to spend a hair over a grand.
Enter the Sigma 50mm f/1.4 DG HSM Art.
While there are no direct comparisons between the Sigma and the Sony GM at the time of writing, it has however been compared with the Zeiss. From the MTF charts we’re seeing from Lensrentals, the Zeiss 50mm f1.4 performs slightly better than the Sigma in the center. It’s in the edges of the frame where the Zeiss proves to be more consistent in resolving fine detail, while the Sigma will exhibit a noticeable dip in sharpness.
Checkout Dustin Abbot’s review of the Sigma 50mm f1.4 ART and see how it performs optically against the Zeiss:
So far, we’ve established that the GM is by far the superior 50mm prime for the FE system, with the Zeiss coming in as a close second. The sub-$1k Sigma 50mm f1.4 ART on the other hand is hot on the tail of the $1,500 Zeiss, at least optically.
What about the AF performance? Well, at least on video mode, the Sigma is the weaker lens in terms of continuous AF and the native lens will be faster and quieter. In photos however, Chris turner says it’s a pretty even match. Have a look at Chris’ awesome video comparing the Zeiss and the Sigma side by side and see for yourself how well the Sigma keeps up with the native Zeiss lens:
Then there’s the Sigma’s weight and size. The Sigma 50mm ART still has the same optical construction as the original 50mm ART lens intended for DSLR cameras, and will therefore have the same larger size and heavier weight. As it stands, the ART lens is right around 37 grams heavier and about 10mm longer than the Sony 50mm f1.2 GM.
Conclusion
So at the end of the day, which premium 50mm is the right one for you? That’s a little hard to give a definite answer to, but I’ll say this. If you demand nothing but the best for your Sony system, then it’s a no brainer; go for the Sony 50mm f1.2 GM. The pros are loving it, and you will, too.
Now if you already have the Zeiss 50mm f1.4, I wouldn’t be too hasty dumping the ZA and springing for the GM, unless of course you want the external buttons and the “declickable” aperture. If you can live with the focus breathing issue present on the GM, you’ll also be getting an optically superior lens that won’t have the onion-ringing on the out of focus elements, and close to zero complaints with chromatic aberrations.
Finally, the Sigma 50mm f1.4 ART will no doubt give you the most bang for your buck out of the three lenses we’ve touched on today. The Sigma ART performs really well overall, only falling a little behind in terms of AF performance. It’ll be a little heavier than the GM, but it does play on the same level of IQ as the Zeiss. For just $950 — half the price of the GM — the Sigma 50mm f1.4 Art is a steal.