Once upon a time, Sigma was a brand thought of by many as the compromise lens if you couldn't afford the household names. Times have changed, though, and Sigma has gone beyond offering competitive lenses to making remarkable lenses and even some notable industry firsts. Being a photographer who works heavily in product work, I decided to put the Sigma 70mm f/2.8 DG Macro Art lens in a shoot-off against the Canon EF 100mm f/2.8L Macro, and the results were... well, read on and find out for yourself!
Before we dive in, I'm going to give you a pop quiz. I will place three images side-to-side for you to guess which was shot with Canon and which was shot with Sigma. These are SOOC (straight out of camera) images with no retouching.
Keep your answers nearby, and we will come back to them at the end.
Now, let me introduce you to the Sigma 70mm f/2.8. It's a light, weather-sealed lens designed for image clarity and true 1:1 magnification for macro photography. After photographing with it for three days, I was unexpectedly impressed with the lens. The truth is, there were some occasions in which I had to turn my camera around to see which lens I actually had on. They both weighed the same amount: 515 g / 18.2 oz. They both photographed sharp, clear, and crisp images. It wasn't until I looked at them in post that I could detect some small differences.
The sharpness between the two seemed nearly indistinguishable to me, which surprised me, because my Canon 100mm is one of my most beloved lenses because of its impeccable clarity. There was one point of differentiation when it came to sharpness. When working on the creme gel macro-texture, the Canon lens struggled to focus. I put the focal point on a highlight in an attempt to give it a higher contrast point, but it did a lot of searching due to the low contrast of the subject. I was frustrated. The Sigma, on the other hand, did not focus-search and took the images quite effortlessly. When reviewing the images on my computer, I discovered that although the Canon lens searched aggravatingly for its focus, it delivered perfectly sharp images on every shot. The Sigma lens, which gave me no problems focusing, delivered a handful of images out of focus, but only about 15-20%. The other 80%+ were impeccable in their quality.
The Surprising, Disappointing Discovery
Just as I was wrapping up my in-studio work, I had one last image on my checklist: my macro texture. For this shot, I reached for my extension tube. If you're unfamiliar with extension tubes, you can read my article here. I shot some beautiful ultra-macros with it and then reached for the Sigma for a few comparison shots. To my surprise, it refused to focus. Categorically, absolutely refused. After troubleshooting and researching, I discovered that the Sigma 70mm is a focus by wire lens. Focus by wire means that the focusing is not mechanically coupled with the focus ring on the barrel. Instead, electronic signals from the autofocus system or the focus ring are received by the focusing motor to achieve focus. Focus by wire lenses are reputed for performing better with autofocus, delivering faster and quieter focusing. This type of focusing system, though, is reputed to underperform in manual focusing, and in my case, with the extension tube, I wasn't able to focus at all. Speaking with a Sigma rep at Imaging USA, I learned that they offer a conversion lens, which functions similarly to extension tubes, amplifying the focal length by 1.2x.
Going into this shoot-off, I intentionally didn't look at the price difference. Once the entire experiment was over and I had made my opinions on the lenses, I looked up the price point of the Sigma. Based on how competitively it performed I expected it to be slightly less expensive, maybe two or three hundred less. The Canon 100mm f/2.8 is priced at $1,299. To my astonishment, the Sigma 70mm f/2.8 came in at a shocking value of only $569 — 57% lower!
Now, having all your facts and technical details, the real test: can you see the difference in the images? It's easy to get geeky with technical jargon about focusing mechanisms and optical designs, but for many of us, it comes down to two simple things: performance and cost. Grab your answers and find out: could you actually tell which lens costs more than double the other?
To me, the difference in the image quality ranged from minor to indistinguishable. It almost pains me to say this, as I'm a serious member of the Canon fan club, but the reality is that the Sigma 70mm is a seriously badass lens. Many times, I had to turn my camera around and look to see which lens I actually had on my camera. It weighed the same, and it shot quietly and sharply. Coming in at less than half the price, it's clear that Sigma has proven that it is producing state-of-the-art lenses at shockingly valuable prices. Am I applying to be a Sigma rep? Not yet. But if I find myself in charge of too many more gear comparisons with the brand, I may feel a little bit like a wayward lover. Sigma delivered a top-of-the-line lens here and made me rethink my perception of the brand entirely.
How did your pop quiz go? Were you correct in identifying which image was shot with Canon and which was shot with Sigma? Have you ever used a Sigma lens? If so, what were your impressions? If you haven't, why haven't you? The most interesting part of my articles is your contributions in the comments below. I'll close the article by sharing some finished images which I shot with the Sigma 70mm f/2.8 DG Macro Art lens.
Which of these lenses do you prefer?