Over the past two years Sigma has easily been the most prolific lens developer on Sony FE and Leica L.  We went from no full frame options from Sigma on Sony’s mirrorless platform two years ago to some 25 lenses just a few years later.  And, while I tend to look at these lenses from a Sony slant (I don’t cover Leica L-mount), often these iSeries lenses (a lineup of compact prime lenses that debuted in late 2019) are designed even more with Leica cameras in mind.  Compact lenses are even more desirable on compact cameras, and while Sony does have the compact a7C full frame camera, there are a variety of L-mount supporting compact cameras, including some from Sigma itself.  The newest lens to join the growing ranks of the compact iSeries lenses is the Sigma 20mm F2 DG DN, the widest lens yet in the series.  If you’re interested in other focal lengths, here is the growing list of iSeries compact prime lenses all hyperlinked to my review of them.

1. Sigma 24mm F3.5
2. Sigma 24mm F2
3. Sigma 35mm F2
4. Sigma 45mm F2.8
5. Sigma 65mm F2
6. Sigma 90mm F2.8

I’ve noted that Sigma’s marketing language for the iSeries is typical marketing word salad (impressive words without much grounding in reality), but the premise for the series is sound.  Sigma has recognized that there are multiple segments within the mirrorless market, and those segments have different priorities.  One group wants maximum performance in aperture and optics, and these are served by Sigma’s larger ART series, but there is a secondary market who bought into the mirrorless vision of smaller and lighter while retaining the performance.  This second group is the target audience for the iSeries.  The iSeries lenses are beautiful crafted, very tactile, but are also much smaller and lighter than other premium lenses.  I’m a fan of the premise, myself, and have liked most of the iSeries lenses quite a bit. *The tests and most of the photos that I share as a part of my review cycle of the i20 (as we’ll call it for brevity) have been done with the new Sony Alpha 1 which will serve as my benchmark camera for the foreseeable future (my review here) along with photos taken with the new Sony a7IV (my review here).

As noted, the i20 is the widest lens in the series thus far, and going wider comes with a lot of additional engineering challenges…particularly when you are trying to create a compact lens like this one.  F2 is actually a fairly wide aperture at this focal length as well.  Sigma does make a 20mm with an F1.4 aperture, but that lens is near a kilogram in weight (the i20 is 370g) and is over 140mm in length in Sony form (this lens is 72.4mm in length).  We are talking about two radically different form factors for these two lenses, and Sigma’s goal in keeping this lens very compact pays dividends in some ways and creates additional challenges in others.  I’ll do my best to detail both perspective as a part of this review.  

The main threat to the i20 on the Sony side is the excellent Sony FE 20mm F1.8 G lens, which I gave a very glowing review of a few years ago.  The Sony has a larger maximum aperture, less vignette and distortion, and is fairly similar in size (the Sony is 84.7mm – 12 long – and weighs 373g, which is almost identical.)  The Sigma does costs about $200 less at $699 USD, which could be a deciding factor for some.  There’s far less choice on the L-mount side, however, with next to no 20mm options (outside of Sigma’s own 20mm F1.4).  I suspect there is more of an audience for this lens there. 

I think Sigma has an uphill battle on its hands on the Sony front, but we’ll find out how the Sigma i20 stacks up in this review.  You can read my text review here, watch the definitive video review here, or just enjoy the photos below!

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Thank you to Sigma Canada (Gentec) for getting me pre-release loaners of the 20mm F2 lens.  As always, this is a completely independent review.  The opinions here are completely my own.

Images of the Sigma 20mm F2 DN

Image Taken with the Sigma 20mm F2 DN

Gear Used:

Purchase the Sigma 20mm F2 DG DN @ B&H Photo | Amazon | Camera Canada  | Amazon Canada | Amazon UK | Amazon Germany | Ebay 

Purchase the Sigma 24mm F2 DG DN @ B&H Photo | Amazon | Camera Canada  | Amazon Canada | Amazon UK | Amazon Germany | eBay 

Purchase the Sigma 24mm F3.5 DN @ B&H Photo | Amazon | Camera Canada | Amazon Canada | Amazon UK | Amazon Germany 

Purchase the Sigma 35mm F2 DG DN @ B&H Photo  | Amazon | Camera Canada  | Amazon Canada | Amazon UK | Amazon Germany | Ebay 

Purchase the Sigma 65mm F2 DG DN @ B&H Photo | Amazon | Camera Canada | Amazon Canada | Amazon UK | Amazon Germany | Ebay 

Purchase the Sigma 90mm F2.8 DG DN @ B&H Photo | Amazon | Camera Canada | Amazon Canada | Amazon UK | Amazon Germany | eBay 

Purchase a Sony a7C @ B&H Photo | Amazon | Camera Canada | Amazon Canada | Amazon UK | Amazon Germany | Ebay 

Purchase the Sony Alpha 1 @ Camera Canada | B&H Photo | Amazon | Amazon Canada | Amazon UK | Amazon Germany | Ebay 

Purchase a Sony a9M2 @ B&H Photo | Amazon | Camera Canada | Amazon Canada | Amazon UK | Amazon Germany | Ebay 

Sony a9 Camera:  B&H Photo | Amazon | Camera Canada  | Amazon Canada | Amazon UK | Amazon Germany | Ebay 
Sony a7RIV Camera: B&H Photo | Amazon | Camera Canada | Amazon Canada | Amazon UK | Amazon Germany | Ebay 

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Keywords:  Sigma 20mm F2, Sigma 20mm DN, i20, Sigma 20mm f2 DN, Sigma 20 F2, Sigma 20mm F2 Review, DN, DG, F2, 20mm, Sigma, iSeries, Wide Angle, Sony, Leica, Hands On, Dustin Abbott, Real World, Comparison, Sharpness, Bokeh, Flare Resistance, Autofocus, Image Quality, Sample Images, Video, Photography, Sony a7c, Sony a9, sony a7IV, sony a7RIV, a7R3,  Sony Alpha 1, Sony A1, Sony a6600