Nikon has been aggressively marketing the internal diameter of the Z mount as being 17% larger than the Nikon F mount, and the larger mount allows more flexibility in the optical design of the Z lenses like their newest 58mm f/0.95 lens.
In this article, I won’t be testing on the 58mm f/0.95 as I’m not really a fan of manual focus. We’ll be taking a look into how the new Nikon 50mm f/1.2 lens holds up against the popular 3rd-party Sigma 50mm f/1.4 Art lens.
Some basic introduction of the Sigma 50mm Art: Sigma has in recent years been developing some impressive lenses that are tack-sharp wide open. Apart from their bad reputation in the past for bad glass coating (that caused chromatic aberration) and front/back focus issue, they have been doing really well since the release of their Art series — they successfully developed lenses that could achieve tack sharp wide open at f/1.4 (although all their lens are quite heavy in weight).
The Sigma 50mm f/1.4 art has been one of my favorite workhorses for all my professional work for the past 2 years.
The Setup
1. Nikon Z6 II and Nikon 50mm f/1.2 S
2. Nikon Z6 II and Sigma 50mm f/1.4 Art with FTZ adapter
The goal of the test: I’ll be doing all my testing at f/1.4 aperture to be fair to the Sigma Art. The purpose of testing at wide open instead of stopping down to f/2 or f/5.6 is to determine the lens sharpness wide open. If I try an f/1.4 lens and it can’t perform well wide open, I won’t see a need to consider such a lens.
Full disclosure: Thanks to Nikon Singapore, I managed to loan both the Z6 II and 50mm f/1.2 S to do some test on them against my own Sigma 50mm Art copy.
Daytime Testing
For this test, my camera was mounted on the tripod to ensure that the setup and the shooting distance don’t change. I also tried to swap the lens quickly so that I could keep the lighting condition to be as close as possible. I stopped down the Nikon lens to f/1.4 to be fair for all the tests.
The first thing I noticed with the Nikon 50mm was the frame appeared tighter than the Sigma 50mm, I would say maybe a 5% tighter in frame although both were 50mm focal length.
In terms of focus sharpness, both lenses were equally good wide open. Zoomed in at 200%, I do notice the Nikon 50mm was a tad sharper on the lines against Sigma art. Having said that, both lenses’ performance were still pretty on par, no client will zoom in 200% to check on your images. Both lenses have what it takes to deliver your work well.
In terms of bokeh, it was quite noticeable that the Nikon 50mm f/1.2 S does have better glass and renders bokeh much smoother than the Sigma 50mm.
Along the white edges of the van, I also saw some green ‘CA’ along the white line in both lenses. The Sigma Art showed stronger green fringing than the Nikon. It’s not really a big issue in general as ‘CA’ correction in Adobe Lightroom is just one click away to get rid of the fringing.
At the extreme right corner of the Nikon 50mm f/1.2 S even after stopping down to f/1.4, it produced a very pleasing bokeh at the corner. The Sigma 50mm Art on the other hand has a busy-looking bokeh.
Nighttime Testing
The focus for this test isn’t just about sharpness as it will be covered in all the other tests. In my nighttime test, I would like to compare the difference in how both lenses produce their bokeh. Who doesn’t love a creamy bokeh from a 50mm?
To test the bokeh, I placed my focus onto the metal railing so that the buildings at the back will be outside the shallow depth of field. The Nikon 50mm f/1.2 produced a significantly larger and smoother bokeh circle at the center and around the mid-frame than the Sigma 50mm.
At the left lower corner of the frame, the Nikon 50mm bokeh turn close to a cat’s eye shape while the Sigma 50mm Art still maintains a nice round circle shape.
At the mid-frame, the Nikon 50mm showed a better shallow depth of effect performance together with some cat’s eye bokeh effect while the Sigma Art maintains its circle effect bokeh around the frame.
For this image, I focus on the tail light of the car so that I could get a shallow depth of field of the street lights in the background. This is a rough guide if you are doing a half-body portrait at night that’s similar to how the bokeh might turn out.
At the mid-frame, Nikon 50mm bokeh appeared slightly more blurred at the long silver street lamp pole. The bokeh on Nikon 50mm also appeared to be brighter than the Sigma 50mm.
At the top corner frame, shooting against the bright street lamp the Nikon 50mm shows a much better control towards flares than the Sigma art. This could be due to the newer coating applied to the Nikon Z lens, where both Nano Crystal and ARNEO coats are used.
How Do They Perform in an Actual Shoot?
Now time for some cute moments in which I used the 50mm lenses to do some pet photography. As the dog doesn’t stay still like humans do, I don’t get to shoot them in the same pose after switching my lens. The pose was slightly different but at the same focus distance.
During the dog photoshoot session, I didn’t notice any difference in terms of autofocus speed. The Nikon new 50mm Z mount focuses pretty quick, I don’t really notice any major difference in focus speed compared to the Sigma 50mm.
Also kudos to Nikon for doing a really good job with their FTZ adapter now, as the adapter focuses relatively well even with a 3rd-party F-mount lens, just like it does with their DSLR series. This is great for photographers who own F-mount 3rd party lenses.
Both images look really great on the dog portrait session, I didn’t notice any big difference in images. Now let’s take a look into the fine details.
At 200% magnification, around the eyes area the Nikon 50mm showed a lot more details. In the eyeball, the details in the reflection details were noticeably sharper! There were also more details in the dark brown fur between the eyes on the Nikon version. On the Sigma copy, the details of the fur were slightly softer, and I don’t really see that ‘wow’ factor in terms of details sharpness.
The Nikon 50mm produces a softer and smoother bokeh compared to the Sigma Art and yet maintained tack-sharp details on the dog face. When I first bought the Sigma Art, I was impressed with how they managed to produce such tack-sharp details at wide-open aperture on their Art lens. It was one of the workhorses ever since.
Now with the new optical design from Nikon Z mount, I really saw some breakthroughs over there. I’m impressed once again after testing out the new 50mm f/1.2. The lens produces such sharp details yet maintaining that smooth creamy bokeh.
Portraits Test
I did a lens comparison during an outdoor family photoshoot with dog owners as well. Unfortunately, I didn’t realize that the owners actually changed their position while I was changing my lens. Other than that, focus distance still remains the same for the test.
At the mid-frame, the bokeh of the tree branches of the Sigma Art seems busy and more contrasty. I definitely prefer the Nikon 50mm for smoother and more natural bokeh.
Similarly, at the corner of the frame, the Sigma 50mm maintains its characteristics of busy background bokeh of the street bushes.
Spec Comparison
In terms of weight, the Nikon 50mm f/1.2 S weighs 1090g and the Sigma 50mm Art with the adapter only weighs 950g in total. When Sigma Art first came out, everyone was commenting on how big and heavy their Art series was. The Sigma Art with FTZ adapter is 130mm in term of length which is 20mm shorter than the Nikon 50mm f/1.2 S (150mm).
While everyone who likes to shoot with 50mm loves an f/1.2 bokeh, this doesn’t just come with a higher price tag. It also comes together with a much bigger filter thread now at 82mm comparing to Sigma 77mm filter size. This means that you might need to invest in an 82mm filter if you need CPL or ND filter. The larger filter will also cost slightly more than the 77mm filter.
More Sample Photos
Here are more photos shot with the Nikon 50mm f/1.2 S. All the photos are taken between f/1.2 and f/2 aperture.
Summary
It is quite a tough call to say Nikon is a clear winner here. In terms of specification and its performance in the real world, I’m sure it is one hell of a lens anyone would love to have. When you start to weigh in other factors like weight, dimension, and filter size, Nikon’s latest 50mm f/1.2 is not a lens for people with weak arms. I know there are people who would sacrifice bokeh and prefer a lighter f/1.8 version then this lens is definitely not for you.
To be able to produce such high quality 50mm f/1.2 lens, the price tag is also double the price of the Sigma 50mm f/1.4 Art F-mount lens. It depends on how much you treasure image quality over weight and price as one of the factors in your decision to get this new Nikon 50mm f/1.2 S.
As for myself, it’s a yay for me as I love tack sharp lenses at wide-open aperture, and that f/1.2 bokeh is just so lovely. This is definitely the lens that will replace the 50mm Sigma Art as my workhorse.
About the author: Andy Chua is a professional photographer based in a Singapore. The opinions expressed in this article are solely those of the author. Chua’s portfolio is 70% sports, and he has covered both local and overseas international meets. His sports work also won several awards in IPA over the years and has been published on different platforms. In addition to sports, he also shoots underwater photography, automotive, products, interior, etc. You can find more of Chua’s work on his website or by following him on Instagram. This article was also published here.