I received a most welcome opportunity from Cameraland to test a new macro lens, the Sigma APO MACRO 150mm F2.8 EX DG OS HSM. My faithful work companion for my macro creations has been the Canon EF 100mm f/2.8 Macro USM 100mm. First of all, the Sigma lens is very heavy. So heavy it has its own tripod collar ring for support. It also has a massive lens hood. It's great that it comes with these accessories but I don't need either since I photograph in very controlled conditions. I photograph at night and on a tripod.
I need darkness for my lighting technique. My exposures are long, a minute and upwards, so I need the camera to be steady and I also need the insect or animal steady. I photograph dead creatures mostly out of a fascination with form and the process of decay. There is also a level of a practicality to it as no living creature stays still if you shine a light on them at night for any length of time. I never kill anything but wait for fauna to drop their bodies in my rural ambient. I'm not sure how happy I would be to take this lens out into the field handheld, moving around as it’s a bit of a wrist strainer. Luckily, I don't have to worry about weight or flexibility.
At first, I worried about getting close enough for the kind of detail I like in the tiny insects and flowers I photograph. But I needn't have worried as my tiny subjects easily filled the frame with a 1:1 magnification. I don't have the problem of scaring away live animals by being too close to them so focal length is not an issue for me. But for live subjects it is most helpful to have a lens that can deliver a close-up image from further away and this lens can definitely do that. When I tried the automatic focus for the first time is when this lens really came alive. It was accurate and fast. The lens also has a focus limiter switch which helps immensely, preventing the lens from going through its whole range, to find focus. Usually I don't even bother with automatic focus on my Canon 100mm, it never finds its mark in my dim lighting conditions, and it just becomes frustrating as it is blurs in and out of its range, wasting battery power.
Of course, one always falls back into manual focussing for complete accuracy in macro photography. But the automatic focus on the Sigma was surprisingly accurate. I work with a wide depth of field using small apertures settings, mostly f18. It was a little bit of a disappointment that the aperture settings on the lens only go up to f22 as sometimes I like to go higher, but it does open up all the way f2.8 making it a wonderful lens for portraits.
I was really impressed with the whole Sigma focussing system. The focus ring is most finely tuned and sensitive as well as easy and smooth to operate - giving one the control one needs for fine adjustment. I was most satisfied with the sharpness I was able to achieve in the final image. No additional sharpening was needed in post-production.
My backgrounds are black, so I did not test the vignetting of the lens on a full frame sensor. I also didn't get a sense of the background blur one gets from a longer lens, which is a necessity for disturbing backgrounds and can create lovely bokeh effects. I also didn't test out the OS Optical Stabiliser system because I work on a tripod and this is not necessary for me.
The Sigma 150mm lens is more than double the price of the Canon 100mm. That is definitely something to weigh up, although, it may be unfair to compare the two as the Sigma comes with accessories and should rather be compared to the Canon 180mm macro lens which is similar in price range. The advantage of the Sigma lens is that Sigma is prepared to convert it to another system should you change brands (you do have to pay for this conversion), but you won't be locked into a particular brand of camera or have to sell your favourite lenses if you switch. This freedom itself is worth any added expense.
Overall, I would say the Sigma is a mighty fine piece of glass.
Catch my exhibition beyond Beyond, infinite and infinitesimal at the Cameraland Gallery – on until the 7th of November including November's First Thursday.
Kali van der Merwe