86mm filter thread

Aperture Variation
150-190mm – f/5
200-240mm – f/5.6
250-290mm – f/6
300-500mm – f/6.3

This is by no means a fast lens.

Buttons and Switches

Zoom lock at 150mm (probably to stop it extending whilst being carried);
Focus switch – M/A Auto with Override; Manual mode.
VR – Off, Mode 1, Mode 2. Mode 1 is panning, Mode 2 damps out all shaking.

Build and Action

Plastic outer casing, and my version has the older Sigma-style speckled black matte finish which scrapes off over time. Wide ribbed rubber zoom ring (further away) and slightly narrower ribbed focus ring (nearer). Metal lens mount. No rubber lens-mount flange.

Focus ring is quite light and smooth, but the zoom ring is very, very stiff, and will tire you out unless you lift weights. To add insult to injury, my copy of the lens has a slow zoom creep that occurs when the lens is elevated to around +/-70 degrees or more due to the sheer amount of glass in the zooming barrel; a small amount of force is required on the zoom ring to keep it still.

However, the gearing is such that you *can* use this as a push-pull lens for zooming. I don’t know whether this will cause long term damage to the lens zoom mechanism, but I’d rather that then have it screw with my wrist. Luckily, most of the time I use it at 500mm so I don’t have to zoom in and out as much.

Although it feels like there is a lot of plastic in here, it feels solid, not just heavy. I’m pretty sure I could bludgeon someone to death with this lens, and after wiping it clean, use it again without problems.

Autofocus Performance

Infinity to Wide to Infinity: 2.1 seconds. No speed stepping up or down with respect to light – this is as fast as it goes.

Autofocus speed is noticeably more leisurely than the 70-300 VR, although there is a heck of a lot more glass to move. Apart from the slow autofocus, accuracy is also an issue. For single shots, given sufficient time to focus, the lens is generally accurate. For tracking/panning subjects, the lens focus is occasionally shifts in and out mid-pan. For the most part, shot focus is generally satisfactory, but every now and then it will blow in or out quite far from intended focus, leading to a badly out of focus shot from a single panning group. This doesn’t happen very often though, but it does happen. Also, due to the slow focus, panning should be done with targets ideally passing in front of you from side to side. If it’s coming towards you at any speed, the focus is too slow to keep up.

At the long end, having a wide aperture of f/6.3 doesn’t seem to badly affect the ability to focus at the extremes of the sensor – I think the lens is a bit too slow-focussing for that to really show up.

As a suggestion, I wouldn’t advise using this lens with a 3D or auto AF modes, unless you’re shooting into a totally clear sky – due to the slow focus, if it goes off-track then it will take some time to wander back into focus.

Optical Qualities

Generally, it’s fair to say that this lens is optimised towards the shorter focal lengths. Colour seems a little more muted than both the Nikon 70-300 VR and 35mm f/1.8 DX, for example. Chromatic aberrations appears the longer you are, especially in the corners.

A particular effect I’ve noticed is that with stabilisation (OS/VR/IS, call it what you will) on, the photo will occasionally have a “halo” effect around subjects of contrast, and not just due to blooming. Stopping down to around f/8 or f/9 mostly eliminates this, as does turning off stabilisation if at all possible.

In terms of acuity, from 150mm to about 300mm, the lens is alright. Ultimate quality doesn’t seem to be as pin-sharp as the Nikon 70-300 VR is capable of between 70 to 200mm, but it might surprise you every now and then. For the majority of shots, it should be almost similar to the Nikon, especially stepped down, but with a lower level of contrast. Colour may be a little less saturated as well. Sharpness across the frame varies as expected, following the traditional centre-sharp, corner-soft arrangement.

From 300mm onwards, the lens starts to go downhill, as one might expect, getting progressively softer. Upon reaching 500mm, which is probably why most people buy this lens, it will probably have to be stopped down to reduce haloing and also to get sharpness/contrast up – without stopping down, the haloing and innate softness will make pictures taken wide open lacking of clarity, unless the subject is close by.

Finally, distant subjects tend to be softer than close subjects at the same focal length. It’s very hard to say how much of this will be due to atmospheric aberrations and thermal shimmer, but in my humble opinion, there is a penalty for shooting farther targets than there is closer ones due to the optics.



The cheapest way to 500mm;
For the focal length, relatively light;
Perfectly servicable optics between 150-300mm
Stabilisation works really well.


The cheapest way to 500mm;
If you thought f/6.3 was bad, it’s actually worse than that;
It’s a Sigma – some are good, some are bad – take your chances;
Autofocus is slow. If it hunts, you’ve lost the shot.


I purchased this lens for the same reason most other people do – to get to 500mm to shoot wildlife. The good news is that it *is* capable of getting pictures at 500mm, but only stopped down as I mentioned previously – that means that, even at ISO 200 or 400, this is a sunny day lens only. You can shoot in overcast weather, but it’s difficult unless you have a steady support. That said, stabilisation is implemented very well here – you can get shots at the long end down to 1/60s, although the success rate is realistically low. But it *is* possible.

At one and a half kilos, it does weigh a bit and will tire you out if you’re not used to lifting such heavy lenses. Then again, this is still a lightweight in comparison to high end super-teles. Now is a good time to practice with that monopod.