This Tamron 18-270mm is a digital-only lens, which means its designed specifically for DSLRs with APS-C sized sensors and can’t be used on full-frame SLRs or older film cameras. Its equivalent focal range is 18-419mm, so it can replace the camera’s standard kit lens and a super-telephoto too, which makes it an extremely attractive proposition because it can effectively replace two to three separate lenses.

At longer focal lengths, camera movement becomes a problem, and to counter this Tamron has built in its own proprietary Vibration Compensation (VC) system. This works like the Image Stabilisation and Vibration Reduction systems in Canon and Nikon lenses respectively, detecting any camera movement during the exposure and instantly adjusting the position of a special element within the lens to keep the image steady on the sensor.

This is designed to reduce or eliminate camera shake, but it has another important effect too – it keeps the image steady in the viewfinder while you’re composing the picture. Camera-based stabilisation systems, as used by Olympus, Sony and Pentax, can be just as effective at reducing camera shake, but they don’t provide this same visual steadying effect as you shoot.

Tamron’s Vibration Compensation system is extremely effective. It cuts in when you half-press the shutter release, and the effect is striking. Normally, with long-range shots, the subject can jiggle around uncontrollably in the viewfinder, but with this system it stops dead in its tracks, and this makes it much easier to get the framing right.

Camera shake isn’t the only potential issue with superzoom lenses like this. The optical challenges involved mean that maintaining image quality over the whole focal range is difficult. The Tamron 18-270mm delivers high levels of sharpness at short and medium focal lengths, but the definition does drop at its maximum zoom setting. This is obvious both from the test results and from real-life shooting, where pictures shot at maximum range are visibly softer. They do sharpen up reasonably well in image editors, suggesting that the problem may be as much to do with contrast as actual definition, but it’s clear nonetheless that at full zoom this lens is right at its limits. There’s also much more colour fringing at 270mm, too – another common characteristic of superzooms at full stretch.

But this goes with the territory. You can’t expect a superzoom to match a conventional telephoto zoom at full stretch, and if you do intend to take lots of pictures at long range you’re probably going to be better off with a lens like Tamron’s 70-200mm f2.8, reviewed last issue. The wide maximum aperture gives you more scope in low light with fast-moving subjects, and it delivers sharper pictures.

As long as you only need a super-telephoto occasionally, though, the 18-270mm makes a lot of sense. It’s versatile, relatively compact and it saves you changing lenses all the time when you’re shooting a wide variety of subjects.

It’s quite heavy, though. On a larger DSLR like an EOS 50D or a Nikon D90, it’s fine, but on a smaller-bodied camera like an EOS 450D or in particular a Nikon D60, it will upset the balance a bit. Not only that, it has a tight spot halfway through the zoom range, which can prove a bit tiresome. You can’t blame the designers because it’s down to the complex movements of the different lens groups as you zoom. It’s unrealistic to expect a perfectly smooth zoom action – it’s amazing that a lens like this can be designed at all.

The other slightly annoying characteristic is lens creep. This is where the lens extends under its own weight if the camera is carried pointing downwards. It’s a characteristic of this lens family and something of an issue with Tamron’s 18-250mm superzoom too. There’s a locking switch on the lens barrel for when the camera’s being carried – this locks the lens at its minimum focal length – but are you really going to want to have to disengage this every time you want to take a picture? The internal focusing (‘IF’) means that the front element doesn’t rotate during focusing, however, so this is an ideal lens for filter fans. The filter thread is just 72mm, too, so Cokin’s P-series filters should work fine with the appropriate adaptor.

This lens has a lot going for it, but it’s not cheap, so you have to weigh up the pros and cons quite carefully. Some drop in sharpness at maximum focal length is to be expected, but here it is pretty obvious. On the other hand, the steadying effect of Tamron’s Vibration Compensation system is remarkable.

The other thing is that this isn’t the only Tamron superzoom to consider. The existing 18-250mm might lack this lens’s vibration compensation, but it’s smaller, lighter and cheaper. In our test featured back in issue 66, it held up a little better at long range, too.

Final Verdict The Tamron 18-270mm is highly versatile, but the drop in definition at full zoom and the fairly high asking price are disappointments OVERALL

Our lens reviewer, and technical expert, Rod is a veritable photographic encyclopaedia. His illustrious CV has seen him write for many mags, websites and journals.