Sony DSLR-A700

Reviewed November 2007

Image Quality

The DSLR-A700 seems to be aimed at the advanced — and well-heeled — but non-professional photographer, if only by the inclusion of Scene modes, modes not generally associated with pro equipment. Still, the A700 is loaded with features that cover from built-in stabilization to a superb 3-inch, high resolution LCD monitor, and which include a 12.2 megapixel resolution, and a full panoply of controls and capabilities.

The DSLR-A700 reviewed here was tested with two lenses. The first was a Carl Zeiss designed lens made for Sony, a Vario-Sonnar T DT 16-80 mm f3.5-4.5 ZA that is equivalent to a 24 to 120 mm. The other was a Sony SAL100M28 100 mm f2.8 Macro lens, equivalent to 150 mm.

The 16-80 mm lens is a very good lens. Images show no chromatic aberration whatever the focal length in use, and only the wide angle end, at the equivalent of 24 mm, is a touch softer focus than the tack-sharp rest of the zoom's range.

The Sony 100 mm, on the other hand is at its best when used for macro shots. While with distance shots the image it yields is, in our opinion, a bit too soft focus for general use and is best reserved for portraits, it is able to produce crisp and distortion free 1:1 macros. (See the macro photo in the Test Photos section of the review.)

The A700 is able to record images in JPEG and RAW formats. The JPEG format has 3 levels of image quality: ExtraFine, Fine and Standard. ExtraFine images offer the highest image quality and use a compression ratio that ranges from less than 3:1 to more than 10:1, depending on the subject. The Fine image quality applies a slightly more aggressive compression in the range of 6:1 to 12:1, but can be sometimes as low as 4:1.

The Standard compression doubles the compression of the Fine mode, often using a compression ratio close to 20:1. As can be expected, although the ExtraFine JPEG format produces excellent images, the RAW format yields an even higher image quality. The A700 offers both a compressed but non-lossy RAW format, and a standard uncompressed RAW format, both of which can be used in combination with a Fine JPEG copy of the image, but not, regrettably, with an ExtraFine copy.

RAW images have to be developed using the software provided with the camera, Image Data Converter, and can be adjusted as desired for a wide variety of parameters if needed.

Generally, however, a simple save of the image in TIFF format — a step the program accomplishes a couple of seconds even though the image has a file size of 34 MB — is all that is required to obtain a very high quality image.

Sony has equipped with the A700 with an 11- point AF system. The selection of the AF point can be left up to the camera, or forced to the area near the centre of the frame, or set to Local, which allows the photographer to select the AF point using the joystick-like Multi-controller. The Local mode is very versatile, easily selected with the thumb, and is very precise. Whatever the mode, by default the AF point in use lights up in red briefly — an option allows this function to be turned off — showing where the focus is set.

One drawback, however, is that if the focus point is on or near a bright area of the frame, it can be difficult to see it when it is lit-up, and can only be confirmed by looking at the monitor's information screen.

With the A700, Sony continues to offer its Dynamic Range Optimizer and increases its performance. The dynamic range optimizer works by analyzing the entire image and optimizing brightness in the areas that are underexposed. Three modes are available on the A700, the first is the Standard mode which is the most conservative, only slightly increasing the brightness of the shadow areas. The second, called Advanced Auto, is a bit more aggressive. The third is Advanced: Level, and offers a choice of 5 levels of optimization.

At 100 ISO, the pop-up flash of the A700 has no trouble providing fill light in an average size room that already a reasonable level of artificial light. But, when this is combined with the Dynamic Range Optimizer — set to Standard mode — that brightens up shadow areas, the results can be significantly brighter images. But, while using the Advanced Auto mode or even the Advanced mode set to Level 5 will yield even brighter images, this will be at the cost of a noticeable increase in noise.

The A700's CMOS sensor has a sensitivity range that starts at 100 ISO. At this level, and up to 400 ISO (100, 125, 160, 300, 250, 320, 400) images are effectively free of noise. The next levels, 500 and 640 start to show some noise, but it is light and is not normally noticeable when images are printed, or seen at less than 100% on a monitor. Noise is more noticeable, even after High ISO noise processing by the camera, from 1000 through 1600 ISO. From 2000 ISO upwards through to the maximum of 6400 ISO, noise is detectable.