So I bit the bullet and bought a Sigma 150-600 Contemporary
Back in April, I was considering buying a telephoto lens and was undecided between the 150-600 models and 70-300s. I finally went with the Tamron 70-300 due to size and weight considerations (read my review here).
However, I took a trip to Point Pelee and Pelee Island in May for the Spring bird migration and, knowing well the shortcomings of the 70-300, rented a Canon 300 f/2.8 + 1.4TC combo. While the 300 2.8L is a brilliant lens, the AF performance suffered a lot due to the TC on my Canon 6D. It is also quite a hefty combination and was very very tiring to carry around all day (I shot handheld as I'm not used to a monopod). Hence the decision to buy a super tele zoom.
There were just 3 such options which would not require me to break the bank - Canon 100-400, Tamron 150-600 and Sigma 150-600 Contemporary. The Canon 100-400 was soon out of the picture due to the shorter reach, although I am well aware of its brilliant image quality. Fortunately, a friend had bought the Tamron a few months ago and we went shooting a few times together, thus giving me an opportunity to use both lenses together in similar situations.
First, the basic specs (additional details can be found at the Sigma official site):
Focal Length : 150mm - 600mm
Max Aperture : 5 - 6.3
Image Stabilization : Yes
Filter size : 95mm
Weight : 1.95 KG
Price Paid : 1200 Canadian Dollars + tax
First of all - the Sigma yields apparently sharper results than the Tamron, especially in low light. This may partially be due to a more effective stabilisation. In good light, they are nearly as sharp but the Sigma seems to have a slight edge.
One advantage with the Tamron is that it has a 1/3rd stop advantage in aperture over most of the zoom range. For example - the Sigma changes from f5 to f5.6 at around 180mm while the Tamron changes only after around 220mm. It also focuses closer than the Sigma.
The physical differences between the lenses are minor :
Zoom direction in the Sigma is the same as Canon's while the Tamron's is similar to Nikon's
The focus ring of the Tamron is wider and easier to grip
Sigma locks across multiple points across the zoom range - and this is a really useful feature
The Tamron has a longer lens hood
The Sigma just looks better and more polished :)
The Sigma includes a strap which can be attached to the lens collar and is useful while carrying
I have been out testing this lens almost everyday for the last month and a half. So, the problems and nags first :) :
One problem I have noticed is the lens hunts sometimes when trying to focus from a near object to a far one. A twist of the focus ring helps and it picks up the subject immediately.
That said, the Chromatic Aberration control is just too good. Check out the picture below. I didn't apply any CA correction because there was hardly any, even in such contrasty light. This is definitely much better performance than the Tamron.
There is almost no Chromatic Aberration
The contrast, colours and bokeh are quite good, though not (as expected) on the same level as the Canon primes. The focal length lets you get some very nice compression and background separation. The depth of field at 600mm f/6.3 is quite narrow, although stopping down to f/8 results in a sharper image.
The lens is sharp, has good bokeh and has a narrow dof
You can use the lens in landscapes too, especially for rich and detailed panoramas.
A boat, quite far out on the lake, shot with the Sigma 150-600 Contemporary
A panorama shot using the Sigma 150-600 Contemporary at 150mm
Fine details like animal fur and bird feather are very well represented, much better than my Tamron 70-300 VC. I would gladly carry the hefty 150-600 over the much lighter Tamron 70-300 for day hikes but its not going backpacking anytime soon, if ever.
Fine details like animal fur are rendered quite well
If you are in the market for a 150-600mm zoom lens, you can't go wrong with either. However, i would pick the Sigma over the Tamron everytime in spite of the minor difference in price.
Some pics taken with this lens:
