As my subjects are predominately portrait based, I usually find myself reaching for a focal length that is 85mm or longer. During the pandemic, however, I found myself wanting a fast but light “normal” lens for my workhorse Sony A7rIII as part of my EDC kit. 35mm primes have been a mainstay in photography as a highly versatile and regarded focal length for both APS-C and full-frame cameras.
My affinity to this focal length is courtesy of the Leica Summicron-M 35mm F2 ASPH, due to the prominence of the 35mm frame lines through a rangefinder window. So on a Sony system how does the new Sigma 35mm f/2 DG DN Contemporary compare?
PREVIEW PROLOGUE
I was instantly intrigued by Sigma’s new I-Series lens trio (24, 35, 65), taking design cues from the previously released 45mm f/2.8 DG DN Contemporary lens. Solid metal housing, aperture ring and a compact footprint is what I had always wanted to be paired with Sigma’s world-class optics and “Made in Japan” excellence in construction and build tolerances.
I had the chance to quickly experience the new 35mm DG DN (translation: full-frame, mirrorless) lens one afternoon. As a quick comparison, I endeavoured to see how it would hold its ground against the only other 35mm prime I was familiar with… The Leica Summicron-M 35 F2 ASPH.
CLEMS CLINICALLY COMPARED ON CAMERA?
I’ve always considered my usage of the Leica 35mm ASPH to be that of a capable environmental portrait lens, wide enough for a scene and with just enough roll-off into the defocus areas to establish a setting. What better subject to sit through this test than Clem Kennedy himself, product manager for Sigma in Australia.
The below two shots were shot from the same spot with a tripod, and aperture wide open at F/2. The Summicron was mounted on a Leica M10, whilst the new Sigma 35mm DG DN was tested on my Sony A7rIII. The raw files were then exported from Adobe Lightroom in jpeg format as-is with no profiles or automatic corrections applied for a fair comparison.
Leica M10 + Summicron-M 35/2 ASPH 
Sony A7rIII + Sigma 35mm F/2 DG DN Contemporary
The results were immediately interesting, even from the rear screen of both cameras… the Sigma exhibiting a slightly wider FOV than the Leica, and some barrel distortion. Clem was strategically placed at the mid-frame as a way to test the lens sharpness outside of the usual center frame. This is not surprising, as there surely must have been some compromise to the lens design in order to keep its compact nature, much like the newer Sigma 85mm DG DN Art lens exhibiting the same performance… a preference for sharpness over distortion. I’m sure in the near future, a profile will be available on Adobe to correct for this, as with most major lens releases.
THE “LEICA” LOOK AND OTHER “LIKES”
With the Leica Summicron as a point of reference in mind, I had already started noting favourable elements to the Sigma. There is a certain “heft” without the lens feeling too overweight like the larger of oft-criticised Sigma lenses made for DSLR’s and retroactively converted to Sony FE mount with the built-in MC-11 adapter.
The new lens features a reassuringly solid construction in it’s all-metal design from the bayonet to the hood (even the focusing and aperture rings are metal ridges as opposed to rubber!) The aperture further adds to the overall tactile experience of the lens, and for those with a Sony A7C, it overcomes the omittance of a front dial, allowing for the same level of manual control on the larger A7/A9 bodies. As quoted from Sigma: “The well-damped manual focus ring, aperture ring, and autofocus switches embody true functional beauty.”
The most interesting addition to this lens is something new from Sigma that I have only seen from filter companies like Kase and Revoring… a magnetic metal front cap! Now, I’m not sure how this would function with filters attached to the front of the lens, however, it is a welcome bonus that adds functionality and a certain luxury to protecting the front element.
On to another lens comparison at the local coffee shop, directly pitting Leica against Sigma… this time with both lenses mounted onto my Sony A7rIII:
Leica Summicron-M 35/2 ASPH 
Sigma 35mm F2 DG DN Contemporary
Once again, the Sigma exhibits a wider FOV and brighter image than the Leica when directly compared on the same sensor. Both were shot from the same point factoring in the longer minimum focus distance of the Summicron… 0.7m vs the closer focusing distance of 0.27m on the Sigma.
Bokeh is subject to personal preference, but I find both to render similarly with nothing too objectionable.
Getting in closer with the Sigma produces buttery smooth bokeh, and at this point, I did not find myself wanting for a faster lens such as their significantly larger F/1.4 or f/1.2 siblings.
FINAL MUSINGS
This was a short hand-on experience. I do believe Sigma is on the right track, finally producing much smaller lenses that are comparatively easier and lighter for everyday carry than their existing lines without much degradation to optical performance or comprising on build quality.
For Panasonic/ Leica shooters, this adds to their first-party full frame line up which currently does not have a 35mm prime option. For Sony shooters, this is another great option to the existing 35mm lenses available, but may suit Sony A7C shooters more, given the addition of the aperture ring which finally allows for proper manual control of the camera.
Is this comparable to a Summicron as I had tested in the short time I was allowed with the lens? The bokeh does appear quite similar, although the Sigma does have the ability to focus closer, not being rangefinder bound. The build quality of the Sigma is as reassuring as that of a German lens, with Sigma stating that the build quality meets the mechanical and operational standards of their Cine lenses.
At the end of the day, isn’t a lens just glass in a metal tube? Most modern lens manufacturers are capable enough of creating an optically excellent or even acceptable lens. Where Sigma scores points this time, is adding to the user’s tactile experience…. and when a camera is seen as an extension of yourself, isn’t that true operational beauty?