When Sigma approached me to ask if I wanted to use their new 120-300 f2.8 lens, I jumped at the chance to shoot with it. And I will say, that I have had the lens in some pretty extreme conditions since I first received it. From the dust filled, hot environment in Mongolia to -31C of the Canadian Cold winter photographing snowy owls, this lens has been put through a variety of extreme tests.
First, I want to address the downside some will notice… Yes, this newly designed Sigma 120-300 covers the range from 120mm to 300mm. What may not be so obvious is that like most zoom lenses, the focal length range is slightly different when the focus distance is significantly less than infinity.
Here is what I mean. I measured the focal length at infinity for the 300mm setting and it came to a real 300mm as expected. However, with the Sigma 120-300 focused down to around 10ft in front of me, and the lens set to 300mm, the actual focal length was around 240mm.
At a focus distance of around 50ft in front of me, I again measured a maximum focal length. This time it came out to 281mm. As I mentioned earlier, most zoom lenses do this, so it’s not a specific criticism of this lens, but it’s something to be aware of when purchasing it.
I bet most of you that know the lens, and have shot with me, thought I was going to say it was heavy and that was the downside. Yes, it is heavier than other lenses at this range, but I hand held this many days and when I wanted more stabilization, I used a monopod or tripod with my Jobu gimball.
Sharpness at closest focus distance (300mm focal length, 2.5m distance) it is a tad on the soft side. But when wide open but at f2.8, it is very sharp. In fact, I would say comparable to any of the Nikkor lenses I have used at a similar focal distance.
I had no issues with focus accuracy on most shots taken with the Sigma 120-300mm F2.8. I have now used it with a Nikon D700, a Nikon D600 and a Nikon. And to be honest, AF was not always absolutely perfect, but was always well within the typical Nikon Specs \i would have expected from a Nikkor or Canon lens.
As a side note.. With the particular camera bodies I used in these tests there did not seem to be any lens bias whether I used front or back button focus.
In regards to tracking speeds, I did shoot some tracking sequences of running horses and flying birds, and most (but not all) of the images were in acceptable focus for me… and remember, I have been in extreme dust and heat and extreme cold, some days with snow falling in front of a white owl against a white background. So all in all, locking on a moving subject has never been an issue, more user error than lens error… LOL
Many of you have asked me about Chromatic Aberration and Vignetting with this lens… Vignetting with the Sigma 120 was very slight, even on full frame. Chromatic aberration, well let’s just leave it at… there has never been an issue in the darkest of photo and under extreme high contrast situations.
In regards to sharpness, it was, and still is, very good at all focal lengths. I have tried the lens from f2.8 through to f11 and was impressed no matter what aperture I used.
The Sigma 120-300mm F2.8 has been a great lens for me. Typically long range zooms aren’t as good as equivalent primes, but this lens does the trick for me and I appreciate the variable distances, making this the perfect lens for the type of shooting I have been doing. It’s well built, solid, fast and optically good. Their new quality control standards are paying off for them. Before, only a sampling of lenses was tested as they came off the assembly line. Now, every lens is tested as it is produced.
But the largest benefit of this lens is the price. At around $3500USD at B&H \photo, nobody is going to say the Sigma 120-300/2.8 is cheap, and I know some would not say it was even “affordable”. But if one is looking for a quality lens in this focal length range, you expect to pay for quality, and the Sigma 120-300mm f2.8 quality is much better value for your money than the Nikkor or Canon comparable.