Not so long ago I looked at the the Panasonic Leica DG Vario-Elmar 100-400 f4-6.3 ASPH Power OIS lens for micro four thirds, well today I’m looking at an alternative lens for APS and full frame cameras – the Sigma 150-600mm f5-6.3 DG OS Contemporary lens. Now confusingly Sigma make two versions of the 150-600 and they are labelled the Sport and Contemporary. The-Digital-Picture.com has put up a good article explaining the difference between the two. The main ones are price and weight with the Contemporary being a 1Kg lighter and $1200 AUD cheaper. This is quite a significant difference and I for one prefer a lighter lens and a heavier wallet. The Contemporary is part of Sigma’s Global Vision line of lenses and is thus compatible with the Sigma TC-1401 1.4x Teleconverter which allows auto focus to work to a maximum of f8 while wide open if your camera supports this feature. This is an interesting option as it allows a reach of 860mm on full frame and a humongous 1376mm on an APSC sensor which is impressive reach for a lens and converter costing less than $2000 AUD. I didn’t happen to look at this option because none of my Canon DSLRs allow f8 auto focusing. shuttermuse.com has an article on f8 focusing with extenders or teleconverters and a list of compatible Canon DSLRs. This does not apply to the mirrorless R and RP which have f11 auto focusing.

Physically this is a large lens, it stands head and shoulders above my Canon 70-200mm f2.8 IS L lens which in itself quite a large lens. The 150-600 is also 500g heavier. At 2.1 Kg with lens hood and tripod collar attached it definitely has heft to it. Interestingly Sigma refer to it as a lightweight lens, I suppose it’s all a matter of perspective as the Panasonic Leica 100-400 is 0.985 Kg so the Sigma feels gargantuan compared to it while the Canon EF 600 mm f4L IS is over 3Kg so the Sigma then seems svelte and compact. The lens body is made out of what Sigma calls a Thermally Stable Composite (TSC) which is substantially stronger than conventional polycarbonates while having similar thermal expansion properties to aluminium. The lens mount is made of chromium plated brass which should ensure a long life. All in all it feels a well made and rugged lens, it may feel like plastic but the TSC body feels substantial and gives the impression of being very durable with no creaking or flexing. The Sigma 150-600 is advertised as being dust and splash proof but on closer reading of Sigma’s spec sheet there is only one seal and that is at the lens mount. If you want better then you’ll have to spring for the Sports version.

When looking at the lens from the front there is a large ribbed rubber zoom ring that has a long throw of about 160º. The action is smooth and feels not too tight nor too loose. As you rotate the zoom ring the lens barrel extends by 8cm. The extension feels secure with no slop or wobble. Just behind the zoom ring on the lefthand side is a zoom lock switch which can lock the zoom ring at the 150mm focal length to prevent zoom creep while carrying the lens. The focusing ring is narrow ribbed rubber and allows you to manually adjust focus while the lens is in the autofocus mode. There are no hard stops which might concern you if you were to use the lens for video. Behind the focusing ring is a panel of four switches and they are:

• An AF switch allowing to choose between AF, MF and MO (Manual Override)
• A focus limiter switch allowing a choice of full range, 10m to ∞, and 2.8 to 10m.
• An optical stabilisation switch that gives a choice of off, on and a panning mode.
• A custom switch that allows you to select two custom modes that can be programmed using the Sigma FD-11 USB Dock

Above the switches is a window showing the focusing scale and then behind that is the lens collar. The lens collar allows you to turn the camera from horizontal to vertical while mounted on a tripod, but, unfortunately there are no detents to allow you to do this while looking through the viewfinder of the camera, you have to align the marks on the collar with those on the lens body. The tripod collar can be detached and thoughtfully Sigma provide a cosmetic rubber ring to slide over the lugs that hold the collar in place. The lens comes with a large plastic lens hood the size of a flower pot, it seems sturdy enough and bayonets into place and a nice touch  is that is ribbed internally to prevent reflections. The 150-600 has a 95mm filter thread which means filters will be expensive and potentially hard to get. In terms of accessories Sigma provide a nice well padded lens case, a shoulder strap for it and a Sigma branded camera strap. Like all Sigma lenses you get a lot for the money you spend. Nice one Sigma!

I tested the lens on a Canon EOS 6d and an EOS 550d to see how it would perform on both crop and full frame cameras. In terms of AF performance as neither of those cameras have what can be considered state of the art AF systems, in fact it is over twelve years old, the lens did very well. The single point AF using the centre point was fast and precise and well capable of fixing on small birds amongst foliage. In terms of continuous AF on the EOS 550d the camera was the limitation being only able to shoot 6 frame bursts in RAW, but out of my six shots when tracking my dog trotting five of the six would be in focus. The 6d is able to shoot 4.5 frames per second for 15 frames and on the trotting bull terrier test it managed 12 frames in focus.

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When it came to BIF (birds in flight not fisticuffs) the AF was more than capable of focusing on and tracking medium to large birds. It really struggled with small birds especially swallows. Put it on a better camera and I’m sure you’d get better results.

 

My primary use for a lens like this is handheld bird photography, and as such I didn’t really give the image stabilisation a workout as I seldom use a shutter speed below 1/500 sec. But messing around at home in the house and garden I figured it was good for three stops. Mind you I do have steady hands so your experience may differ from mine.

 

 

The optical construction of the lens is twenty elements in fourteen groups with 1 FLD and 3 SLD elements. The FLD (“F” Low Dispersion) glass element, which offers performance equivalent to fluorite.  Canon and other manufacturers have used synthetically grown crystals of calcium fluoride components in lenses to aid apochromatic design, and to reduce light dispersion so lenses made from it exhibit less chromatic aberration. What Sigma has done is use newer glasses and computer-aided design to render the use of fluorite crystals unnecessary. Sigma claim that the FLD element is “highly transparent, its refractive index and dispersion are extremely low as compared to conventional types of glass. It offers characteristics very similar to those of fluorite, which is valued for its anomalous dispersion. These characteristics minimize residual chromatic aberration (secondary spectrum), which cannot be corrected by ordinary optical glass, while helping to produce sharp, high-contrast images.” (https://sigmaphoto.com.au). The three SLD (Special Low Dispersion) glass elements also help to minimize chromatic aberration. To help achieve attractive out of focus transitions there are nine rounded aperture blades which should help achieve nice round bokeh balls when shooting specular highlights.

 

 

In terms of optical performance well I’ll deal with full frame and crop separately. First up using the lens on the crop framed 550d. At 150mm the centre of the lens wide open was sharp and contrasty and stayed A as such until f22 when it softened due to the effects of diffraction. At the edges the peak performance was attained at f11 and remained until f22 when it softened again. At 600mm the centre wide open was a little soft and lacking in contrast. This improved by f8 and then deteriorated at f22. The edges weren’t so good – wide open they were soft and lacking contrast and remained so until f22 when they got worse. As for vignetting well at the short end wide open it was apparent, about 1/2 to 1 stop and this disappeared by f8. It was the same story at the long end. Throughout the focal range there is slight pin cushion distortion and some chromatic aberration can also be seen. Open the files up in Lightroom and apply the lens profile and things improve nicely. On the full frame 6d the story is the same except for the vignetting which is naturally worse at around 1-1 1/2 stops which is totally understandable as you are using the whole frame rather than just the central part of the lens coverage.

 

 

What’s all this mean in real life. Well if we look at the image for the New Holland Honeyeater which I took at a distance of around 3.5 to 4 metres and then enlarge the section around the head you can see that there is nice feather detail and that the eye is sharper than a very sharp thing. To get much better you’d have to spend an awful lot of money and if we look at the Canon 600mm f4 lens I mentioned earlier that has an eye watering price of $18,500 AUD which is over 11 times the cost of the Sigma. Personally I know that if I plonked $18 K down on a lens I’d be heading for the divorce court which would make the Canon a doubly expensive lens. So for what it costs the Sigma is amazing value.

Below are some examples of bird photography shot with the lens on both a Canon EOS 6d and 550d.

So would I recommend the lens? Yes without hesitation. It performs very well and is sold at a very good price and you can’t argue with that.