I make a couple of premises, what follows is not the result of “lab tests”, you will not find comparisons between shots to sheets and plush toys. I write simply my impressions of practical use of the Sigma 150-600 in the field (rather cold and snowy) of Hokkaido, the northernmost island of Japan. I think the best way to get a real idea of the qualities, strengths and weaknesses of any piece of equipment is prolonged use in the most variable conditions. Hey, after all, it is a lens designed especially for nature photography, is reckoned a little ‘dirty work. Second, luckily in the past i had the opportunity to use and possess undisputed level telephoto lenses, both in terms of construction and functionally. This to me is not a secondary because I think I can say to have a clear idea of what is “sharp” or a snappy autofocus performance. I admit I thought it was a bet going on a trip like the one I did at Hokkaido, deciding to take with me as the only “long” solution 150-600 the sport and leave home my 500 f4, a guarantee. Unfortunately the different flights to bring and the baggage already too heavy led me to having to make a choice. To increase the sense of pre-departure anxiety, I withdrew the lens 2 days before leaving, so the time for test shots was practically zero, and (no kidding, witness my traveling companion) I ran an auto-calibration using the dock, at Tokyo airport waiting for the final flight to Hokkaido. Probably a more rigorous method would lead to even better results. I can peacefully and happily say that, after shooting with this super-zoom around 7,000 images in various situations within about 20 days, to be happy to have left home the 500 f4. I never once felt of having a not sufficent tool for the job.
Leaving aside the technical aspects strictly objective, which can be found on Sigma website, there are some aspects in particular that I consider essential to evaluate a lens quality. The sharpness and image quality in general, the speed and consistencyof the autofocus and the construction quality as well as operation functionality. I start from the sharpness that is within the nebulous and hazy world of what is called image quality. Surely the aspect that interests most of us photographers, but that to me is one of the aspects, certainly not the only one. How sharp is the sport 150-600, ? The short answer: a lot. At close distances (another advantage never too much considered the minimum focusing distance of only 2.6 meters) The sharpness is impressive, I can safely say that we are close to what can be done with the best fixed focal lenghts. Enclosed you will find some images, some of then even cropped heavily, in testimony of what I say.
I have often used the lens at 600 mm, but in general at any different focal lengths, the qualityexpressed is very homogeneous. The test where I was almost sure to see a failure was on long distances subjects. In the past I have used other “noble” zoom (one among the others, the Nikon 200-400) and in subjects at long distances i’ve always noted a significant drop in sharpness. Here I can happily say that after a brief calibration performed with the appropriate dock, even over long distances the detail remains legible. In my case and for my personal way of photographing is an important element, because I often want to include as much enviroment i can in many images, so the subject is often far away
Another aspect variously connected to the image quality is the quality of the out of focus areas, bokeh, etc etc. In this field I have to say that I received the first real surprises from this super-zoom. Considering that the maximum aperture to longer focal lengths is 6.3, the quality of the out of focus areas is very good. You can see in some of the pictures I’ve attached, deer and foxes shot at ground level on an icy lagoon against the light. Of course if I had used my old 400 2.8 the result in that sense would have been even better, but we talk about a lens that weighs almost twice, costs 6 times as much and especially has not the zoom versatility. Other aspects related to the image quality I have appreciated are the lack of chromatic aberrations but especially the excellent management of the backlight also very strong. Some of the images that I chose to show is emblematic in this respect, Deer with full sun in the frame and a series of backlit images taken with a strong glare on ice. Really a great job in this regard. In my case, anything but secondary aspects since I try to photograph backlight whenever possible.
Now, the autofocus. To me a more important aspect than clarity in strict sense. From this point of view the 150-600 sport has behaved very well. Both from the point of view of speed, both as regards the consistency of the same sequences of more shots to subjects with varying distances. In this respect I want to say a few words on that Sigma USB dock conceived long ago and the possibilities related to it. All the objectives produced in recent times by Sigma are compatible with the use of the dock, a small accessory that connects the lens to your PC, allowing for example to upgrade within seconds the lens firmware, or make fine calibrations of autofocus or even create your own functions to be assigned to the custom function buttons. In fact, according to the situations you may find you can set up and customize the lens accordingly. Better to talk about practical examples, however, in my case I have decided to create a customized setting autofocus by limiting the range of 5 meters to infinity. In some areas of Hokkaido I found myself photographing swans and eagles in flight or at considerable speed fights and set this limit made the autofocus significantly faster. Useful to say the least, considering it is something that anyone can do without having to ship the lens to assistance for days. Some of the images that I chose to show is a testament to the autofocus goodness. Even here, a fixed focal lenght behaves even better but must be considered a fundamental aspect at least in my way of considering photography. If I had used my 500 f4, I could have some images even sharper and with an even better bokeh but for sure lose a lot of images by cutting wings, head, tail or maybe just not be able to take so much images hand held, thing that i prefer the most for speed and compositional reasons.
Last but not least i speak of the construction quality of this lens. Simply EXCELLENT. Once in your hands you realize immediately the quality with which it is assembled, pleasant to the touch and smooth operation of the rings and Zoom or the quality of the buttons. The immediate impression is that of a product designed to last and to be used for a long time. I do not make secret of the fact that i treat pretty bad my equipment, and i do not use special regard. In Hokkaido I often photographed in the snow or strong wind and never protect the optics from bad weather and I never had any problems of any kind, despite one of the features is precisely the barrel extension when you zoom.
One of the features that I have been able to appreciate more and more, it concerns the doublemode of zooming, the conventional one and the other, “pump mode”. The latter in particular allows you to dial in a manner much faster. Particularly useful for shots of birds in flight or on approach.
Finally, the “OS” stabilizer for example, I’ve used almost only in mode 1. Very very quiet hardly noticeable and very effective, I quietly took pictures 1/60 sec to 600 mm without having to use a tripod or monopod which also rarely use.
Finally, what I wrote does not mean that the 150-600 sport is better than fixed focal lenghts. It could not, and is not designed for this.
The point is that in many cases, and experiencing it on the field, the difference in quality is thinner that you think while having the versatility that hallows it to cover nearly all focal useful to those who want to photograph wild animals not to mention the cost compared to that of equivalent fixed focal. Of course the maximum aperture is 5-6.3 but modern dSLR deal very well with high sensitivity.
I, for all pictures taken in Japan I only used two lenses, the sport precisely 150-600 and 24-105, leaving at home a lot ‘of extra weight.