The price tag reflects the build quality and performance of Sony's fast 70-200mm f/2.8 G lens. Compatible with APS-C format and 35mm sized sensor cameras, it covers a focal length range of 105-300mm with the former. The fast f/2.8 maximum aperture is available at all focal length settings, as is the minimum aperture of f/32. Eight contacts inside the lens mount allow the lens to interact with compatible camera bodies.
The Sony 70-200mm f/2.8 G lens shown in side view, without the supplied tripod collare and lens hood. (Source: Sony.)
Designed as one of Sony's G (for ‘Gold') series lenses, which represent professional quality, the 70-200mm f/2.8 G contains 19 elements in 16 groups. Four ED (Extra-low Dispersion) glass elements have been included to correct chromatic aberrations and provide high resolution across the full zoom range. Internal focusing supports fast autofocusing and allows the use of angle-critical attachments like polarisers and graduated filters.
This lens is one of the last to be based on the original Minolta designs and, as such, represents a minor update to the original lens. Accordingly, it's more suited to ‘full-frame' cameras like the A850 (which we used for our tests) and the A900, where its 1.34 kg weight is better balanced. (We were unable to test the lens on an APS-C format DSLR body.)
On first acquaintance, the build quality of this lens appeared to be outstanding. The solid metal body felt rugged enough to withstand the rigors of professional usage. Unfortunately, as far as we have been able to ascertain, no environmental sealing has been included, which is surprising for the price of this lens.
The metal parts of the lens barrel are painted cream to reduce heat absorption - a useful feature for Australian photographers that Canon has capitalised on for many years. A tripod collar and petal-shaped lens hood are provided with the lens. The former slips onto the back of the lens barrel and is clamped into place with a collar-locking knob, which must be loosened when you change the orientation of the camera body from horizontal to vertical.
The lens hood fits on with a bayonet mounting and adds approximately 95 mm to overall length. It has a ‘window hatch' with a sliding cover that can be opened to allow adjustments to polarising filters. You can attach the hood to position this window hatch at the top or bottom of the lens. However, the hood should be removed for flash photography so light from the flash is not blocked.
The focusing ring is a 31 mm wide band near the front of the lens barrel. It has a finely-ridged rubber coating that provides a secure grip. Just behind it is one of three focus hold buttons that are arranged at 90 degrees around the left side of the lens barrel. These buttons are used to toggle the camera between AF and fixed focus and you can press one of the buttons to fix focus on a specific distance (obtained with the AF control).
Behind the top focus hold button lies a distance scale, with distance markings in metres and feet, ranging from 1.2 metres (the closest focus) to infinity. To the rear of the distance scale is a 45 mm wide zoom ring, which has a broad (36 mm wide) ridged rubber grip. The trailing edge of this ring carries engraved markings for the 70mm, 100mm, 135mm and 200mm focal length settings.
The left side of the lens barrel behind the zoom ring carries three slider controls, all of which control focusing settings. The top one is a simple AF/MF switch. The second is a direct manual focus (DMF) switch with two positions: STD. and F TIME. Both allow manual focusing when the focusing ring is rotated. The STD. setting only works when the camera is set to AF-A or AF-S focusing modes, while the F TIME setting is designed for shooting fast-moving subjects and works with the AF-C mode.
The third slider is a focus range limiter, which is used to minimise the time needed for the AF system to lock onto subjects by reducing the range of distances over which it will operate. Two positions are provided. Full engages autofocusing throughout the entire range of the lens but prioritises focus on close subjects. The infinity to 3m setting ignores close subjects and restricts the minimum focusing distance to three metres.
The built-in SSM (Super Sonic wave Motor) is similar to the USM motors on Canon lenses or Nikon's SWM motors. Like its competitors, it provides fast, almost silent and accurate autofocusing.
In addition to the tripod collar and lens hood, the 70-200mm f/2.8 G lens comes with front and end caps plus a semi-soft carrying pouch with a double-zip closure and shoulder strap. Multi-lingual instruction leaflets are also provided, along with a brochure detailing accessories.
Handling
Despite being a large and heavy lens, the review lens felt comfortable on the A850 body we used for our tests. Both focusing and zoom rings showed no slack yet moved smoothly and positively and the overall length of the lens remained constant throughout the focal length range.
The zoom ring moves through approximately 45 degrees of rotation and we found the markings on the lens barrel to be accurate for the indicated focal length settings. The focusing ring can be moved through the full 360-degree circle in MF mode but requires roughly 270 degrees of rotation to encompass the full focusing range. Precise manual focusing is relatively easy as a result. Although no ‘macro' settings are provided, it is possible to shoot attractive close-ups of flowers and other small subjects - provided the camera-to-subject distance required is greater than 1.2 metres.
Performance
Test shots taken with the review lens on the A850 body were generally sharp and detailed and Imatest showed the lens to be a good performer that delivered consistently high resolution between f/4 and f/11 for almost all focal length settings. However, edge softening was greater than we had expected for a lens of this calibre at all focal length settings and all apertures up to f/11.
We obtained the best results with the 200mm focal length setting and (surprisingly) the lowest resolution figures at 135mm. The graph below shows the results of our Imatest tests.
Lateral chromatic aberration was consistently in the ‘low' band, just venturing into the ‘moderate' category at f/22 with the 200mm focal length setting. Interestingly it was consistently negligible throughout the aperture range with the 100mm focal length setting. The graph below shows the results of our Imatest tests. (The red line marks the border between 'negligible' and 'low' CA, while the green line shows the edge of the 'moderate' band.)
We found no evidence of significant rectilinear distortion throughout the zoom range, although very slight barreling could be seen at 70mm and marginal pincushion distortion at 200mm. However, neither would affect normal photography.
Vignetting could be seen at f/2.8 for all focal length settings. It was more noticeable at longer focal lengths than at 70mm. Stopping down to f/4 eliminated this problem. Flare was also a non-issue when the lens hood was in place. However, it was possible to produce flare spots when shooting towards the sun when the lens hood was not fitted, as shown in the illustration below. Note that overall contrast remains high despite the flare spots.
Flare; 70mm focal length, ISO 100, 1/125 second at f/14.
Bokeh at wide apertures was reasonably attractive - although not outstanding, particularly when there was plenty of background detail to subdue. We noticed a tendency to outline partially-resolved areas at f/2.8. However, this was largely resolved by stopping down to f/4.
Buy this lens if:
- You want a fast, professional quality telephoto zoom lens for Sony's A850 and A900 DSLR bodies.
- You require performance levels to match the capabilities of Sony's ‘full-frame' Exmor sensor (and are prepared to pay a premium price to obtain them).
Don't buy this lens if:
- You require a relatively lightweight lens.
- You need close focusing and macro capabilities.
IMATEST GRAPHS
SAMPLE IMAGES
70mm focal length, ISO 100, 1/40 second at f/14.
200mm focal length, ISO 100, 1/60 second at f/14.
Bokeh with distant background; 200mm focal length, ISO 100, 1/320 second at f/2.8.
Bokeh with close background; 200mm focal length, ISO 100, 1/4000 second at f/2.8.
70mm focal length, ISO 100, 1/160 second at f/10.
A crop from the above image at 100% magnification showing the absence of coloured fringign and edge effects.
Vignetting at 70mm, f/2.8 (ISO 100, 1/2500 second).
Vignetting at 100mm, f/2.8 (ISO 100, 1/2500 second).
Vignetting at 135mm, f/2.8 (ISO 100, 1/2500 second).
Vignetting at 200mm, f/2.8 (ISO 100, 1/2500 second).
Additional images can be found with the review of the Sony DSLR A850 camera.