Camera Accessories

The name alone should be an assurance to knowledgeable photographers that the Sony CZ Planar T* 85mm F1.4 ZA is no ordinary lens and the 'Planar' tag reflects its noble ancestry. The original Planar was a six-element symmetrical lens designed by physicist, Paul Rudolph, at Carl Zeiss in 1896. It was very popular with serious photographers for its speed and pictorial qualities and offered consistent performance over a wide range of imaging ratios.

The design was particularly renowned for its sharpness and became the basis for nearly all professional general-purpose lenses. Its only weakness was susceptibility to flare, due to its large number of air-to-glass surfaces in the design. For a decade or so, the Planar design lost favour to the four-element Tessar design that was less flare-prone. Fortunately, was revived in the 1950s when high-quality anti-reflection coatings became available.

Coating technology has evolved over the years to reach a very high standard in the T* coatings developed by Carl Zeiss. These coatings have solved the flare problems and allowed Planar lenses to dominate the normal (50mm) to short tele lens category. Sony's new SAL85F14Z lens is designed and manufactured by Carl Zeiss specifically for Sony's DSLR cameras and provides a focal length equivalent to 127.5mm on the DSLR-A100 model.

Smaller, but just as solidly built as the Sonnar T* 1.8/135 ZA lens, it has many similar features. Nine aperture blades contract to provide a circular aperture with very attractive bokeh (out-of-focus blur). However, close focusing is limited to 85 cm, making this lens less suitable for capturing details and small objects than the 135mm lens. The 85mm F1.4 Planar T* is supplied with a similar lens hood and carry-pouch and also features a focus-hold button, distance and depth-of-field scales and wide, ridged focusing ring with an auto clutch that prevents unintentional re-focusing in AF mode.

As a midrange telephoto lens, the 85mm F1.4 Planar T* is brilliant for portraiture and its wide maximum aperture allows you to take pictures in low light without having to increase sensor sensitivity unduly. Focusing at full aperture is fast and precise, although the resulting depth-of-field is very shallow. Stopped down to between f/4.0 and f/11, overall sharpness is outstanding and images are distortion-free.

Performance
Our tests involved both Imatest evaluation and field tests where we used the lens to record a number of different subjects. For the former, we compared the resolution of the Carl Zeiss 85mm F1.4 Planar T* lens with Sony's 75-300mm f4.5-5.6 kit lens. In the field we concentrated on the types of subject best suited to this lens.

Overall performance was quite similar to that of the Sonnar T* 1.8/135 ZA lens, as you can see from the graph below. Highest resolution was measured between f/4.5 and f/11 and our MTF50 figures remained above average all the way to the minimum aperture of f/22, although diffraction produced a measurable decline in resolution. Correspondence between horizontal and vertical MTF50 measurements was close, although not quite as close as with the Sonnar T* 1.8/135 ZA lens. Lateral chromatic aberration was also low enough to be negligible, although not quite as low as the Sonnar T* 1.8/135 ZA lens.



Results of our field tests were similar to the tests on the Sonnar T* 1.8/135 ZA lens. In low light conditions, the 85mm F1.4 Planar T* produced 'punchier' pictures than the Sony 75-300mm lens at the same focal length with richer colours and sharper subject definition. This is not to say that the Sony zoom lens is bad (in fact, on the contrary); it's just that the Carl Zeiss prime lens delivers noticeably better pictures - as you would expect from its design and price.
Flare was unnoticeably in backlit shots and out-of-focus areas were very attractively rendered. Autofocusing was very fast and very accurate, thanks largely to the wide maximum aperture. No distortion was observed and image sharpness and brightness remained constant across the field of view at all lens apertures. Overall, this lens was a delight to use.

SAMPLE IMAGES

Close focusing capabilities are modest but the wide maximum aperture supports differential focusing and bokeh is very attractive.

Flare is very well controlled when shooting backlit subjects.

This lens is superb for portraiture, especially in subdued lighting.

Maximum aperture: f/1.4

Minimum aperture: f/22
Lens construction: 8 elements in 7 groups

35mm focal length equivalent on A100 camera: 127.5mm

Angle of view (on A100): 19 degrees

Minimum focus: 0.85 m
Filter size: 72mm
Dimensions (Diameter x L): 81 x 75 mm
Weight: 645 grams