The Sigma 17-70mm – A lens for the indecisive?

By Dr Alex Tattersall

As seen in UWP magazine

Fellow dSLR users, have you ever noticed the gleeful look in the eyes of the compact user on those two occasions in particular?

1. Airport checkin. How smugly they breeze through airport check-in and customs without the need for crippling excess baggage charges. Bypassing the adrenalin pumping Russian roulette of praying that your 20kg hand luggage Pelicase is not going to be weighed by the over-zealous check-in assistant who is having a bad day. Never having to sport the ‘haute couture’ photographer’s jacket stuffed to the top with batteries, lenses, strobes, and all manner of ‘essential’ accessories.

2. The pre-dive dilemma. Every time they hear that familiar mantra of us poor dSLR underwater photographers before every dive: “macro or wide angle?, macro or wide angle?, macro or wide angle”.

Perhaps we have an answer to occasion number two.

We all know that lens choice will determine both photographer mindset and photographic opportunities for the next hour, even potentially condemning us all to a series of missed opportunities for making an incorrect choice. Have we, dSLR users, not all been party to that fantastic macro behaviour whilst equipped with a super wide-angle fisheye lens or that monumental large animal interaction whilst sporting a super macro setup?

I have recently returned from a Dr Alex Mustard photographic workshop in the Red Sea which gave me the opportunity to test a number of lens setups with the Canon 7D in its Nauticam housing. One previously largely overlooked lens in my collection made a steep climb in popularity for use in those wonderful, clear-blue, Red Sea water conditions. We spent several days at Shark and Yolanda reefs, Ras Mohammed, on the very tip of the Sinai Peninsula, as June is the time for huge aggregations of schooling fish. At the same time however, the sites boast such macro favourites as the long-nosed hawkfish, pyjama nudibranchs and the wonderful leopard blenny. Enter the Sigma 17-70mm whose versatility earned it pride of place on my camera for a last six dives of the week.

The Sigma 17-70 comes in three different versions, the early and now discontinued 17-70mm F2.8-4.5 DC Macro, a later HSM (Hyper Sonic Motor meaning quicker focusing) version of the same lens (only available in a Nikon fit and on the verge of being discontinued), and the recently released 17-70mm F2.8-4 DC Macro OS HSM which features image stabilisation on top of the high speed focusing of the previous model. The diameter of the lens has become progressively wider with each new version and this should be borne in mind when purchasing corresponding zoom gears. It should also be noted that these lenses extend significantly on zooming, the older style (non-OS) versions requiring a 50mm extension when coupled with a 8.5” Fisheye dome on the Nauticam. The later OS version extends further and requires a 60mm extension on my setup. Full specification details for those interested can be found at the Sigma imaging website.

Although this is entitled a ‘macro’ lens, I found it impractical to use with a flat port due to the length of extension when moving through the zoom range. It is therefore best used behind a large dome port, from my experience. Maximum magnification is in the region of 1:2.5 so its application is not suited to very small subjects.

I was using the original non-OS and non-HSM lens on the recent trip and I was very pleased with the results. Since the lens focuses very closely, I did not need to use a dioptre throughout the zoom range and the corners of the shots were always very sharp, even at relatively open apertures.  The lens has a relatively close working distance of some 4cm which has the obvious advantage of not requiring an additional dioptre. A disadvantage though with this close working distance is remembering not to get too close, as I discovered to my dismay when I saw the deep grooves in my shiny new dome port.

It is however the versatility of the lens which makes it such a winner in my eyes. One caveat before we look at some images is that this article has been conceived as a result of the images and the experience of using the lens, not vice versa. Consequently, I have to admit that this was therefore not the most systematic testing of the lens but I hope my experience is helpful. I am also not the first person to suggest the Sigma 17-70mm as a good mid-range lens for UW photographer. I seem to remember, perhaps three years ago, seeing photos taken by Ross Gudgeon that compelled me into investing in this relatively inexpensive addition to my armoury.

Note that all photos are uncropped. Thanks to Christian who spotted this beautiful long-nosed hawkfish at 20 meters on Shark reef. This first shot shows the field of view at 22mm,

Canon 7D, Nauticam NA-7D, 8.5” Nauticam dome, extension 50, 2x INON Z240 Sigma 17-70mm@ 21mm F7.1 1/50 ISO 200

This is the same field of view (more or less) at 30mm,

Canon 7D, Nauticam NA-7D, 8.5” Nauticam dome, extension 50, 2x INON Z240 Sigma 17-70mm@ 30mm F7.1 1/50 ISO 200

At 44mm,

Canon 7D, Nauticam NA-7D, 8.5” Nauticam dome, extension 50, 2x INON Z240 Sigma 17-70mm@ 44mm F7.1 1/50 ISO 200

And at 70mm.

Canon 7D, Nauticam NA-7D, 8.5” Nauticam dome, extension 50, 2x INON Z240 Sigma 17-70mm@ 70mm F7.1 1/50 ISO 200

At about 15 meters on Shark reef was a cleaning station and individuals and groups of batfish were leaving and rejoining the huge school aggregated in the blue. The Sigma 17-70 allowed me to take shots of both small groups and individuals.

At 17mm

Canon 7D, Nauticam NA-7D, 8.5” Nauticam dome, extension 50, 2x INON Z240 Sigma 17-70mm@ 21mm F9 1/125 ISO 200

At 44mm

Canon 7D, Nauticam NA-7D, 8.5” Nauticam dome, extension 50, 2x INON Z240 Sigma 17-70mm@ 44mm F9 1/125 ISO 200

At 62mm

Canon 7D, Nauticam NA-7D, 8.5” Nauticam dome, extension 50, 2x INON Z240 Sigma 17-70mm@ 62mm F9 1/125 ISO 200

I think the above shots demonstrate well the versatility of the lens and the high quality and stunning colours of the resulting photos. It was a pleasure to be able to have the both macro and the wide-angle opportunities at my fingertips.

Canon 7D, Nauticam NA-7D, 8.5” Nauticam dome, extension 50, 2x INON Z240 Sigma 17-70mm@ 50mm F9 1/60 ISO 200
Canon 7D, Nauticam NA-7D, 8.5” Nauticam dome, extension 50, 2x INON Z240 Sigma 17-70mm@ 22mm F9 1/250 ISO 200

Perhaps then, fellow dSLR user, we have an answer to combat the smugness of the compact user, with their dastardly wet lenses and their infernal lens mounts. Of course, that is only once we have successfully run the heart-thumping gauntlet of the airline check-in, foiled the highly-trained, crack-command airport security team and nonchalantly, oh so very nonchalantly, lifted the hernia-inducing 20kg Pelicase into the suddenly rather flimsy looking overhead locker. Who, but us, could ever understand how finally coming to sit down in the comfort (!) of a cramped charter airplane seat could ever feel so sweet?

PS I am now stocking this lens at a very favourable price for those of you who are UK based. I tried to resist a commercial plug, but could I? No.

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