The Tamron 18-250mm offers a huge 13.9x zoom range. That’s even longer than a fancy ‘super-zoom’ compact. It’s designed specifically for DSLRs with APS-C sized sensors, so once you’ve applied the usual focal factor, it equates to a 28-390mm. Not many photographers will regularly need to shoot wider or longer than that, so it makes a great everyday lens and an interesting alternative to a kit zoom and telephoto combination.

This lens is available in Nikon, Canon, Pentax and Sony fits (we tested it on a Nikon body). There is one thing to point out, though. The Tamron doesn’t have lens motors and relies on the AF motor in the camera body. This means that autofocus will be impossible with the Nikon D40 or D40x because these bodies don’t have AF motors (a cost-cutting measure made possible by the fact that Nikon zooms do have motors).

When you get this lens out of the box it’s hard to believe it has the focal range advertised. It’s just a little fatter and longer than the average DSLR ‘kit ‘ lens, and not much heavier, either. Of course, when you zoom in, the length changes considerably, though the lightweight construction means the camera never becomes ‘front-heavy’ and unbalanced. What you do get, though, is pronounced ‘zoom creep’. The weight of the lens’s internal elements means that as soon as you point the camera downwards, the zoom extends. And since most of us have the camera pointing downwards when we’re not actively shooting, it does become a constant annoyance.

Tamron has included a Lock switch on the barrel for locking the lens at 18mm, but while this is useful for storing and transporting the lens, you won’t want to keep switching it on and off between shots.

The Zoom ring is large and smooth in its operation, and while the front Manual Focus ring is quite small and slightly ‘coarse’ feeling, it’s much more effective than the wobbly afterthoughts on the front of some cheaper lenses. The lens uses internal focusing and the front element doesn’t rotate, making it perfect for filter fans.

Overall, the build quality is very good and a cut above the lenses usually bundled with DSLRs, but what about the picture quality? Well, lenses never give you something for nothing. The Tamron’s focal range is huge, its cost is comparatively low and it’s not much larger or heavier than a standard ‘kit’ zoom. Something’s got to give optically.

The good news is that while the optical compromises aren’t hard to spot, they’re far from unacceptable. We’re used to zooms showing noticeable barrel distortion at the wide-angle end of the zoom range, and this applies to the Tamron. At its 18mm setting, any straight lines near the edge of the frame clearly bow outwards. However, it’s not a lot worse than the average kit zoom in this respect. By 70mm it’s swapped over to fairly marked pincushion distortion, where straight lines near the edge of the frame appear to bow inwards instead. This again is typical of zooms at longer focal lengths, though it’s surprising to see the Tamron doing it so early in its zoom range. At longer focal lengths, however, this pincushion distortion seems to diminish, so by 250mm it’s still visible but not quite as strong.

We’re also used to some degree of chromatic aberration in all but the most expensive zoom lenses, and the Tamron exhibits this throughout its focal range. It’s not particularly noticeable at shorter focal lengths, but it does become more obvious by 250mm. Fortunately, it does seem to be fairly clearly defined and a simple adjustment of the Red/Cyan slider in Photoshop’s Lens Correction filter removes most of it.

The big surprise, though, comes from the resolution figures. Most zooms tail off badly at their longest focal lengths, even much more modest ‘kit’ zooms (our Nikon 18-70mm, for example). The Tamron, though, holds up exceptionally well, and even at 250mm it’s almost as sharp as it is at 70mm and 18mm. Many long-range zooms are actually pretty weak at long range, but this one (chromatic aberration aside) is excellent. Even better, it’s sharp when it’s absolutely wide open, which is exactly what you need in a telephoto with a restricted max aperture.

Yes, there are optical compromises in this lens, but these are inevitable. What’s striking is not just its focal range and how useful this is in everyday photography, but its ability to maintain good sharpness at all apertures and focal lengths.

Final Verdict Inevitable compromises aside, you'll enjoy this lens’s stunning versatility and surprisingly consistent sharpness 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.