Articles

In my constant quest to find the best possible optics for creating pictures underwater, I was once again drawn to a macro lens that I’d never used—the Sigma 105mm f/2.8 DG DN Macro Art lens. This isn’t a particularly new lens, but it seems to be largely overlooked by Sony (and L-mount) shooters. Released in 2020, the lens is still considerably newer than the aging Sony FE 90mm f/2.8 Macro G OSS.

Based on the recommendation from a good friend, I took the plunge and picked up the lens for myself when I stumbled across one for a great price. I will rarely buy anything without having tried it myself first, but I made an exception this time. So, did I make the right call? You’ll have to read on!
 

A male banded jawfish mouthbrooding a fresh clutch of eggs. Longer focal lengths like 105mm allow for better separation from background distractions, especially at wider apertures (Sony a1, Sigma 105mm f/2.8 DG DN Macro Art, Isotta housing, dual Marelux Apollo III 2.0 strobes, f/7.1, 1/320s, ISO 250)

Build and Features

The Sigma 105mm f/2.8 DG DN Macro Art has an interesting design for a modern lens. Most uniquely, in a throwback to bygone times, it features an aperture ring. Of course, this isn’t relevant to underwater shooters, but it brings back a bit of nostalgia. The lens must be set to “A” on the aperture ring to allow the camera to control the lens’ aperture. The 1:1 macro lens offers a minimum aperture of f/22, while the minimum focusing distance is 11.6in (29.5cm).

The Sigma 105mm f/2.8 DG DN Macro Art
 

For us underwater shooters, the ergonomics of a lens don’t matter much, as they are inside a port all the time anyway. That said, the build quality is decent. There is a focus limiter switch, which normally I’d never touch, but I think with regards to the Sigma lens, I might actually use it to improve the autofocus performance; more on that in the autofocus section. There are a few extra buttons and switches that are unlabeled and thus I have ignored. Not unique to the 105mm is a nice heft, so your rig will likely be a bit front heavy underwater.
 

A young polkadot batfish with a very clown-like aesthetic. Batfish are notorious for turning their back on you while you try to photograph them. The 105mm is a great focal length to give a bit more distance between subject and camera, perhaps making the batfish more comfortable (Sony a1, Sigma 105mm f/2.8 DG DN Macro Art, Isotta housing, dual Kraken KR-S160 strobes, f/14, 1/320s, ISO 100)

Autofocus Performance

While it absolutely excels in other areas, the Sigma 105mm Macro Art’s largest weakness is its autofocus prowess, or more accurately, a lack thereof. While it isn’t bad, the lens is noticeably slower than both the Sony 90mm Macro G and the Tamron 90mm Di III VXD Macro.

If the subject is close to the plane of focus when the lens starts focusing, it does a decent job of quickly locking focus. However, if the lens has to make a more dramatic change in focus distance, it can be aggravatingly slow while the lens racks in and out before finding the subject. Once it is locked on the subject, it does a fine job of staying with the subject. Once you understand the lens’ limitations and how to work around them, you’ll likely not have too many issues with the autofocus performance.

As previously mentioned, I suspect the autofocus performance could be improved by setting the focus limiter switch to “0.295–0.5m” if shooting mostly very up-close subjects. No doubt this is when something exceptional appears and is just beyond that focus distance, so please don’t hold that against me if you set the limiter switch!
 

A male sailfin blenny displaying for rivals or nearby females. The 105mm focal length gives great subject separation from backgrounds, really drawing focus to the critter. The one drawback of the Sigma 105mm Macro Art is the relatively slow autofocus performance. Even on my Sony a1, it is noticeably slower than the Sony 90mm and Tamron 90mm lenses. This isn’t a deal-breaker, but it is something to keep in mind (Sony a1, Sigma 105mm f/2.8 DG DN Macro Art, Isotta housing, dual Kraken KR-S160 strobes, f/7.1, 1/30s, ISO 250)
 

Longer focal lengths are wonderful for skittish subjects like this hovering dartfish. Even shot at a wider aperture, the Sigma 105mm Macro Art is quite sharp. When this image is viewed at full resolution, you can even see his tiny bulldog teeth and slight underbite (Sony a1, Sigma 105mm f/2.8 DG DN Macro Art, Isotta housing, dual Marelux Apollo III 2.0 strobes, f/4.5, 1/320s, ISO 125)

Image Quality

As I have harped on in many a review, image quality of whatever I’m shooting is the most important aspect of that product for me. Of course, the Sigma 105mm Macro Art lens is no exception. The sharpness and overall optical performance are wonderful. To my eye, it produces sharper results than the Sony 90mm Macro G and I’d say equivalent to the Tamron 90mm Macro.

I’m echoing much of what I said in my review of the Tamron 90mm Macro lens, but I think they are quite comparable with regards to image quality. I’d love to shoot the Sigma 105mm Macro Art behind my curved macro port, but I don’t have the proper extensions. Behind a flat port, the Sigma lens holds up well with regard to controlling chromatic aberration, and sharpness remains decent in the corners of the frame.
 

The Sigma 105mm Macro Art boasts excellent image quality. In my opinion, it surpasses that of the Sony 90mm Macro G lens and is quite similar in terms of sharpness to the Tamron 90mm Di III VXD Macro lens. The 100% crop (bottom) shows brilliant sharpness and you can even see the tiny teeth on this dragonet (Sony a1, Sigma 105mm f/2.8 DG DN Macro Art, Isotta housing, Kraken KR-S160 strobes, f/10, 1/320s, ISO 100)

Final Thoughts

For anyone looking at a macro lens for the Sony ecosystem, the Sigma 105mm f/2.8 DG DN Macro Art is a great alternative to the Sony or Tamron 90mm macro lenses. Personally, I find the 105mm focal length more appealing and useful than 90mm. While the Sigma 105mm Macro Art is significantly slower focusing than either of the 90mm options, the sharpness and image quality are fantastic. The lens also retails for several hundred dollars less than the Sony 90mm and is roughly the same price as the Tamron lens. While I generally gravitate towards shorter focal length macro lenses like my 50mm, I don’t regret buying the Sigma 105mm f/2.8 DG DN Macro Art. Perhaps that is all that really needs to be said!
 

A striated frogfish lit with dual snoots. The 105mm focal length on full-frame cameras is perfect for portraits of my favorite group of fish—the anglers! (Sony a1, Sigma 105mm f/2.8 DG DN Macro Art, Isotta housing, dual Kraken KR-S40 strobes with Backscatter OS-1 snoots, f/13, 1/320s, ISO 100)
 

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