Tamron’s 100-400mm is both compact and lightweight which makes it quite comfortable to use hand-held. A tripod mounting collar is available as an optional extra.

If you’re spending all your own money on camera gear then telephoto lenses can be a bit of a luxury, particularly primes which tend to be more specialised the longer in focal length that you go.

A telezoom could be a good solution, but what focal range? Regardless of your area of interest, you’ll probably want to go as long as is practicable (and your budget will allow), but still have plenty of shorter focal lengths on tap for more general shooting.

In the light of this, 100-400mm looks pretty good, doesn’t it? The 400mm focal length still gets you in close for sports and wildlife while the remaining 100mm to 300mm is useful for a whole lot of subjects. If this lens is also comparatively compact and affordable, then you’re even better off… which is why Tamron’s new 100-400mm f4.5-6.3 model looks like a very appealing way of gaining some more focal length ‘fire power’ without tying up your money in a lens that you’ll only use once in a while. Tamron is on fire at the moment and its 100-400mm telezoom is the lens to have if the G2 series 150-600mm is just a bit too big and too expensive. For the record, the 100-400mm is around $900 cheaper (that’s another lens purchase right there) and 900 grams lighter, so it’s easier to carry around and certainly easier to shoot with when hand-held.

In fact, Tamron is so confident that you’ll mostly use it handheld that the tripod mount collar is an optional extra which, depending what way you look at it, is either a saving or an additional cost. Frankly, we’d like to have the collar because it’s likely that, sooner or later, you will need it, in which case you can add $199 to the bill (which, it has to be said, seems to be a bit steep for a small lump of metal).

The really bad news is that this lens only available in the Canon and Nikon D-SLR mounts with, it would seem, no plans to cater for either Pentax or Sony users, but if you have an ‘APS-C’ format body you effectively get a 150-600mm telezoom anyway.

In The Hand
In terms of its size, the Tamron 100-400mm is similar in dimensions to an f2.8-speed 70-200mm zoom and the fact that it accepts 67 mm screwthread filters is an indication that it’s actually less bulky than many of these models. Of course, 67 mm filters are less expensive than 77 mm or 82 mm.

All the barrel tubes are magnesium alloy with weather sealing at the various joints and junctions which is important for a lens that’s very likely to be used in all sorts of weathers. There are eight seals in all, including a substantial rubber gasket around the lens mount. The protection against the elements includes a fluorine coating on the exposed surface of the front element which is designed to help repel both moisture and grease, but also makes for easier cleaning.

The styling is Tamron’s new ‘clean’ look with flush-fitting collars for both focusing and zooming, a locking switch and a small panel which houses two additional switches for the focusing and image stabiliser modes. The focusing switch can be set to either MF or AF with a third position marked ‘Limit’ which, as you’d expect, reduces the autofocusing range to save time if you know exactly where your subject is going to be. You can select from one of two distance ranges depending on the current focus setting – shorter than seven metres and the range will be 1.5 to seven metres, longer and it’ll be seven metres to infinity. However, if you also invest in Tamron’s TAP-In console which hooks your lens up to a computer running the free TAP-In utility, you can actually pick your own changeover distance, which is pretty handy. The 100-400mm’s minimum focusing distance of 1.5 metres gives a maximum reproduction ratio of 1:3.6 which is a bit over one-third lifesize (1:3.3 on a full-35mm sensor) and means even quite small subjects can be reproduced full-frame… such as small birds or animals. Many telephoto lenses have quite long minimum focusing distances as well which means a smaller magnification ratio and so some limitations when shooting, for example, wildlife (at least not without cropping the image later on).

The ‘Vibration Compensation’ optical image stabilisation has two modes for normal shooting and for panning. It provides up to four stops of correction for camera shake.

Steady On
Optical image stabilisation is via Tamron’s ‘Vibration Compensation’ (VC) system which, on this lens, has its own dedicated high-speed microprocessor to enhance response times, further assisted by revised control algorithms.

As a result, the 100-400mm’s stabiliser gives up to four stops of correction for camera shake. Using the 1/focal length rule this means that when shooting 400mm you could, theoretically at least, get away with using a shutter speed of 1/25 second. At lot will depend on how steady you can actually hold 1.1 kilograms’s worth of lens (plus the camera body’s weight, of course), but this amount of correction at least gives you more flexibility with handheld shooting and also means you could very well get away with using just a monopod where normally a tripod would be necessary. There are two VC modes, one for full correction and one which switches off the lateral compensation to allow for panning, recognising that sports photographers use this technique a lot. The autofocusing also gets its own processor which again is designed to enhance the response speed and more precisely control the focusing drive in terms of starting and stopping.

The optical construction employs 17 elements in 11 groups and three of these elements are made optical glass with low-dispersion characteristics primarily to minimise both axial and transverse chromatic aberrations, but as a consequence also enhance sharpness.Tamron’s ‘eBAND’ multi-coating is used to reduce reflections and so help control both ghosting and flare. The initials stand for “Extended Bandwidth And Angular-Dependency”… no, we don’t know what it all means either.

The diaphragm employs nine blades to give smoother out-of-focus effects and on both mount versions it’s electromagnetically controlled to give better frame-to-frame exposure accuracy with continuous shooting. However, as far as Nikon users are concerned, this means the lens isn’t compatible with any pre-2007 D-SLR bodies should they happen to be still in action.

The minimum focusing distance is 1.5 metres, giving a useful maxium magnification ratio of 1:3.6.

In The Field
Our test period with Tamron’s 100-400mm conveniently coincided with the Bathurst 12 Hour race for GT class cars held at the legendary Mount Panorama circuit. This race is unique in the world in that it actually starts in the dark (at 5.45 a.m.) and so there are a number of photographic challenges involved with trying to shoot fast-moving subjects in very low light. Additionally, the racing cars’ lights – and they all use a lot more than just headlights – can play havoc with the metering.

We decided to test out the idea of ‘no tripod’ shooting with the 100-400mm even in this most extreme of conditions. Initially it meant winding the sensitivity up to ISO 6400 and even then the shutter speeds were still quite slow which meant hoping that the image stabilisation was doing its job. However, even with a Nikon D4 on the other end, the Tamron 100-400mm was still very easy and comfortable to carry around and it’s rare to be able to travel light with motorsport photography. All that was left in the photo backpack were spare batteries for the D4, a couple of filters, cleaning cloths and a water bottle. Luxury!

As the sun started to come up, it was possible to start winding down the ISO, but it was still too dark for the autofocusing to work reliably (which is when you wish for a Nikon D5!). What was becoming apparent though, was that the 100-400mm focal range was near-perfect for this job. At 100mm, the angle-of-view was wide enough for more atmospheric shots of the track, especially at sunrise. Around 150mm to 200mm was great for panning at many locations while 400mm allowed you to get in much tighter for cornering shots. When there was eventually enough light for the D4’s autofocusing to harness its full resources, the 100-400mm USD drive had no problems keeping up.

It was important to remember to switch stabiliser modes when panning (and you’ll do this quite a lot during a long race), but otherwise everything else is quite effortless. And, certainly as the day started to warm up significantly (as it can in Central NSW), the lighter load was very welcome.

Test images captured as JPEG/large/fines with a Nikon D4, using shutter-priority auto exposure control, auto white balance and the Vivid ‘Picture Control’ preset. Sharpness is exceptional across the focal range and at all apertures, but the best centre-to-edge uniformity is achieved between f5.6 and f11. The image quality at 400mm is superb, enabling the full potential of the focal range to exploited. Chromatic aberrations are non-existent and vignetting is minimal. Flare and ghosting are well controlled.

Performance
We’ve already commented on the autofocusing and image stabilisation – certainly two staples for motorsport photography – so suffice to repeat here that both work very effectively and very reliably indeed. Being able to shoot at around 1/50 or 1/60 second when there is very little light around is a real bonus. The shots we took are a bit grainy because of the very high ISO setting, but that’s obviously not the lens’s fault.

Optically, the 100-400mm is a star performer with excellent overall sharpness and seemingly very effective correction for chromatic aberrations.

The uniformity of centre-to-corner sharpness is consistently good across both the zooming and aperture ranges with the crispness of the definition in the corners peaking between f8.0 and f16. It’s really exceptional at 400mm which is why a pure telezoom is ultimately a better proposition than a superzoom because although it may be a little less versatile overall, it’s the telephoto end that suffers when an optical design also has to deliver wide-angle focal lengths.

Flare only happened when the lens was pointed directly into the rising sun and then the effect was actually quite controlled rather than a blotchy mess. Again, the contrast remains nicely punchy across the zooming range and we didn’t experience any issues with vignetting, regardless of the aperture setting.

Commendably, we didn’t see any issues with focus breathing (a slight change to the focal length when focusing) either.

The Verdict
Working with a lens is a sure way to make or break the relationship, but the Tamron 100-400mm simply kept on proving its worth in every shooting situation.

Its size and weight meant it remained comfortable to handle even after shooting for hours on end and while we didn’t really put the durability to the test (well, we did have to give it back in one piece), it certainly feels well-made and able to withstand a bit of wear and tear… which comes with the territory in both sports and wildlife photography.

The optical performance is the biggest surprise, however, as this lens delivers far beyond what you might expect for the price. In comparison, Canon’s L series 100-400mm f4.5-5.6 IS II USM is currently priced at $2799 while Nikon’s AF-S 80-400mm f4.5-5.6G VR model is around $3400 which is a lot more again despite the slightly wider focal range.

On every level the Tamron lens underscores those price differences with its build quality, operation, performance and sheer usability - which all serve to highlight the one aspect that is undoubtedly the biggest in its class… value for money.

Tamron 100-400mm f4.5-6.3 Di VC USD (Model A035) 
Format: Full-35mm digital sensors. The focal range is effectively 150-600mm on an ‘APS-C’ format sensor (with a 1.5x focal length magnification factor).
Angle-of-View: 24.24 to 6.12 degrees (diagonal).
Construction: 17 elements/11 groups.
Minimum Focus: 150 cm (across the focal range).
Maximum Reproduction Ratio: 1:3.6 (at 400mm).
Aperture Range: f4.5-6.3 to f32-45.
Overall Length: 196.5 mm.
Maximum Diameter: 86.2 mm.
Filter Diameter: 67 mm.
Weight: 1115 grams.
Lens Mount(s): Canon EF and Nikon F (G-type AF).
Features: Magnesium alloy barrel tubes, weather-proofed barrel and mount, fluorine coating on front element’s exposed surface, built-in ‘Vibration Compensation’ optical stabilisation (dual modes), zoom lock, USD autofocusing drive, internal focusing group, focus limiter, electromagnetic diaphragm control, nine-blade diaphragm, three LD (low dispersion) glass elements, ‘eBAND’ anti-reflection multi-coating. Bayonet mount lens hood supplied.
Price: $1299. Optional tripod mounting collar available at $199.