Go telescopic with an extra-long zoom lens. Matthew Richards compares the latest and greatest contenders
Get closer to the action with a super-tele zoom, for wildlife and sports
Whether you’re shooting wildlife, sports, boats or just about anything else you can’t get close to, it’s frustrating if your zoom lens can’t cover the distance. A zoom range of 70-300mm is fairly standard for telephoto zooms, and on a DX-format Nikon, the 1.5x crop factor bumps the ‘effective’ focal length up to a mighty 450mm, but that can still come up short.
Super-telephoto zoom lenses have been growing in stature and telescopic power over the past few years. A maximum reach of 400mm used to be par for the course, and indeed Nikon’s two most upmarket zooms in this category are still based on this figure. However, Sigma and Tamron stretched the envelope to 500mm, and then to 600mm, making even the latest, more budget-friendly Nikon 200-500mm lens look a little behind the times.
Naturally, if you’re used to shooting with a 70-300mm lens on a DX body, and then upgrade to
Even if you’re sticking to DX-format shooting, the effective reach of 900mm makes these lenses very tempting
an FX (full-frame) Nikon, you’re likely to be disappointed by the shrunken telephoto reach. Indeed, upgrading to a 400mm lens still wouldn’t give you as much reach as using a 70-300mm on a DX body, while Nikon’s 200-500mm would only give you slightly more. In this case, you might feel that one of the Sigma or Tamron 150600mm lenses is the best option. And even if you’re sticking to DX shooting, the effective reach of 900mm makes these lenses very tempting.
Apart from the older of the Tamron 150-600mm lenses (not the new G2 edition), all of the lenses on test are compatible with the latest versions of teleconverters from the same manufacturers. But there’s a catch when it comes to autofocus: a 1.4x teleconverter narrows the widest available aperture by a stop, so an f/5.6 lens effectively becomes an f/8 lens. With a 1.4x teleconverter attached, autofocus will only be available in recent, upmarket DSLRs that feature autofocus at f/8, which rules out D3XXX and D5XXX cameras. Attach a 2.0x teleconverter that narrows the aperture by two stops, and autofocus will be unavailable on any camera.
Handheld photography can be something of a struggle with a couple of the heavier lenses on test, and with these a monopod might become your new best friend. Either way, blurred images caused by camera-shake are an ever-present danger. The rule of thumb for handheld shooting is that you need to have a shutter speed that’s at least as fast as the reciprocal of the
effective focal length to get consistently sharp shots. So, if you’re shooting at 600mm on a DX-format camera, which gives you an effective focal length of 900mm, you’d need a super-fast shutter speed of at least 1/1000 sec – and steady hands – to avoid blur due to camera-shake.
Bearing in mind that supertele zooms typically have a ‘slow’ aperture rating of f/5.6 or f/6.3 at the long end, getting a fast enough shutter speed under anything other than bright sunlight can be a challenge, even if you bump up your ISO setting. It’s no surprise, then, that all current super-tele zooms for Nikon DSLRs feature optical image stabilization, or Vibration Reduction in Nikon parlance.
A fast autofocus system is another ‘must-have’ feature for super-tele zooms. This is because this type of lens is so often used for shooting sport and wildlife, where you need to be able to track moving subjects. All of the lenses on test therefore have fast (and quiet) ring-type ultrasonic autofocus systems – but, as we’ll see, some examples are more refined than others.