Digital Photographer - UK (2019-08)

Left

400mm, f8

The extra telephoto

reach at 400mm

is clear to see, but

sharpness drops

off and colour

fringing becomes

noticeable

Above

18mm, f8

At the shortest zoom

setting, sharpness is

less impressive than

with any other lens

on test, but barrel

distortion and fringing

are well-controlled

Above

This Tamron goes

large in every way

Physically wider, longer and

heavier than all of the other

lenses in this test group,

the Tamron rules the roost

for telephoto reach

group testgroup test

what it lacks in width it

makes up for in length,

as tamron unleashes yet

another ‘world-first’ in

the superzoom category

Serving up a longer minimum focal length

than Tamron’s 16-300mm lens, the

company’s latest superzoom kicks off at a

more mainstream 18mm. At the long end,

however, it stretches to a class-leading

400mm, putting every other superzoom in

the shade for telephoto reach.

Along with the extra focal length, the

18-400mm is scaled up in physical size. At

79x124mm and weighing 705g or 710g for

the Canon or Nikon mount options, it’s the

biggest and heaviest lens on test. It’s still

lighter than Nikon’s older 18-300mm f/3.5-

5.6 superzoom, and the 72mm filter thread

is no larger than in the Sigma lens.

The high-spec optical path includes two

moulded glass aspherical elements and one

hybrid aspherical element. Three LD (low

dispersion) elements are also incorporated,

with the aim of increasing sharpness and

contrast, and reducing colour fringing.

Compared with the autofocus system in

Tamron’s 16-300mm lens, this one has an

upgraded HLD (high/low torque-modulated

drive) motor. It’s quick and quiet, uses less

power, and the motor’s speed is adjusted

to ensure smooth and accurate focussing.

However, the focus ring rotates during

autofocus and precludes full-time manual

override. In this respect, it’s similar to the

autofocus system in the Sigma lens on test.

There’s a downturn in performance when

it comes to optical stabilisation. Tamron’s

VC systems are usually rated at 4 or 5 stops,

but the stabiliser here only has a 2.5-stop

effectiveness. On the plus side, the lens is

well-built with various weather-seals, with a

rubber ring on the mounting plate.

At the shortest zoom setting, sharpness

is poorer than with any of the other lenses

in the group. It’s not inspiring at longer focal

lengths either, where sharpness is slightly

better than from the Nikon lens but lags

behind the other two on test. Distortions

are quite well-controlled at all zoom settings,

where amounts of barrel and pincushion are

similar to those of the Sigma 18-300mm.

Colour fringing is fairly minimal at most

focal lengths but becomes as noticeable

as in the Tamron 16-300mm lens at the

longest zoom setting.

Tamron

18-400mm f/3.5-6.3

Di II VC HLD

Price: £670/$649

x2 © Matthew Richards