Digital SLR

Sony's long-awaited second DSLR, the Alpha (α) A700 features a larger, tougher body and a new Exmor-branded CMOS sensor with 12.24-megapixel resolution. Noticeably larger and roughly 150 grams heavier than Sony's first DSLR model (the A100), it is targeted at serious enthusiast photographers and boasts a faster image processor, improved dust and moisture resistance, a larger LCD monitor and a brighter viewfinder.

Body & Controls
Built for durability and reliability, the A700's internal chassis is made from high-strength aluminium alloy, while its top and face plates are magnesium alloy. Weather-resistant silicon seals protect media card slots and control buttons against the entry of dust and moisture. Anti-dust technology combines an anti-static coating on the low band-pass filter covering the image sensor with sensor-shift anti-dust vibration.

Dual slots are provided for Memory Stick Duo and CompactFlash cards and users can select which card to record to. The Memory Stick Duo slot supports Memory Stick PRO Duo and Memory Stick PRO-HG Duo, the new high-speed-transfer product. The CF slot supports the UDMA(Ultra Direct Memory Access) standard and accepts 300x (high speed data transfer type) cards.

The right-hand grip is one of the most comfortable we've used, with mouldings to accommodate the second and third fingers. This positions the index finger perfectly for operating the shutter button. A moulded extension on the rear panel positions the photographer's thumb securely and allows the camera to be used one-handed, should the need arise.

Covering most of the rear panel is a huge (3.0-inch) Xtra Fine LCD monitor with 921,000 dots of resolution. It boasts a hybrid structure and anti-reflective coating to provide better viewing in sunlight and also claims a 2.8x improvement in contrast over the A100's screen. Although far from perfect, this monitor can be used in bright sunlight - but we wouldn't advise basing exposure or colour accuracy decisions on it in such conditions.

Sony has also included an HDMI terminal in the new camera so photographers can display their shots on large screen Full HD TV screens. (An optional HDMI cable and a TV supporting HD input are required for viewing HD still images.) With Sony's 'Bravia' TV sets, the camera's special "PhotoTV HD" playback delivers spectacular picture quality. We believe this facility will be a valuable aid for selling images for photographers who shoot weddings and special events.

The schematic diagram above shows soem of the key features of the A700.

With the A700, Sony has introduced a new 'Quick Navi' interface that enables key camera settings to be accessed via a joystick plus icons on the LCD. The Function button is used to switch on the Quick Navi screen. A dedicated Custom button, which is located just above the Function button, can have a frequently used function (such as file size, focus area selection or ISO settings) assigned to it for one-touch access. Creative Style settings are assigned to this button by default.

The Quick Navi function makes it easy to select and adjust all key photographic controls.

The shutter mechanism on the A700 has also been improved and now offers a top shutter speed of 1/8000 second with flash synch at 1/250 second with Super Steady Shot off or 1/200 second with it on. The new camera's shutter is also rated for 100,000 cycles, which suggests it's more solidly constructed. Continuous shooting speeds have been increased from three (which is still available in 'Lo' speed mode) to five frames/second and up to 18 raw files can be stored in the enlarged buffer memory.

The NP-FM500H Info Lithium battery pack claims to deliver high energy density/high output current but is only CIPA rated for approximately 650 shots per charge, 100 less than the A100. We're not sure why this should be so but perhaps the new processor and higher resolution of the imager place greater demands on the power system.

Sony is also offering an optional vertical grip for the A700. Designed primarily to assist with portrait shooting, this grip screws onto the base plate and carries shutter and AE-L buttons, a power switch and front and rear control dials. It can accommodate up to two battery packs to provide greater scope for shooting. Charge levels of both batteries (when fitted) are displayed separately on screen for unambiguous indication of remaining power.  

 
The DSLR-A700 with the vertical grip fitted.

Under the Skin
Beneath the surface, the A700 includes some important enhancements, the most notable being the use of the new CMOS sensor. This chip combines 'cultivated CCD imaging' (whatever that is) and Sony's original On-Chip Column A/D conversion technologies with a Dual Noise Reduction Circuit, enabling the camera to read out the image signals at high speed with reduced image noise.

As far as we have been able to determine, some analogue noise reduction processing takes place before analogue-to-digital (A/D) conversion. The image data then passes to dedicated A/D converters that are located close to each element array on the sensor itself. Further on-chip noise reduction processing is carried out once the signals have been digitised. The image data is then passed from the sensor to the new BIONZ image processor, where the raw image data is subjected to further noise reduction processing before the image data is compressed to produce JPEG files.

The A700's autofocusing system combines a pair of central cross-type AF sensors with 10 surrounding AF points to cover a wider area. A high precision F2.8 AF sensor placed above the central point delivers a precision improvement of approximately 1.3 times over the current model. A dedicated AF illuminator is provided so photographers no longer need to rely on the flash for focusing in dim lighting and with low-contrast subjects. Movement prediction AF ability has been also enhanced to capture fast-moving subjects and lens driving control time is faster for subject distance calculation and focus position, offering approximately 1.7 times faster focus speeds than the A100 model.

AF area selection is provided.

The D-range Optimiser (DRO), which featured in the A100, has been improved and is now adjustable in five increments. Used to adjust contrast and hue with backlit and high-contrast subjects, its now includes an advanced bracketing mode captures the same scene at five different DRO settings to provide the best possible results.

Sony has also expanded the image file options in the A700 with the addition of a new compressed raw mode (cRAW), which records slightly smaller raw files and compresses them to reduce the file size by roughly 30%. We're not sure whether this compression is lossless but our test files looked pretty good. JPEG files can be recorded at three sizes: 12M, 6.4M and 3.0M. Three JPEG compression levels are supported: Extra Fine, Fine and Standard, producing files that in our tests averaged 11.3MB, 6.5MB and 4.8MB respectively. Raw files were around 18.8MB, while cRAW files averaged just under 13MB.


Image resolution options.

In addition, two aspect ratios are supported: the standard 3:2 and 16:9. The latter setting, which produces 'widescreen' pictures, crops JPEGs top and bottom but leaves raw files in 3:2 format, allowing photographers to shoot widescreen JPEGs and standard raw files simultaneously when RAW+JPEG is selected.

An interesting new feature in the A700 is the Creative Style function, which provides 14 'picture style' settings, including Standard, Vivid, Neutral, Adobe RGB, Portrait, Landscape and B&W. The first four provide adjustments for contrast, saturation, sharpness, while the Portrait, Landscape and B&W styles add brightness and zone matching (although saturation is not provided in B&W mode).

The Creative Style menu.

This menu is the only way photographers can elect to shoot in the Adobe RGB colour space. Users can also customise existing styles and three memory banks are provided for registering different combinations of settings. We suspect this function has been added to compete with other manufacturers, although we suspect most users of this camera will stick with the P, A, S and M settings.

Playback options are extensive. Users can choose between displaying shots at full screen size - with or without shooting data. Image thumbnails can be tiled as four- nine- or 25-up displays or the last five images shot can be 'stripped in' above the currently selected shot. This last mode is great for checking bracketed exposures. In addition, a thumbnail image can be displayed with an RGB histogram and basic shooting data.

 
 
Some of the playback settings provided.

Unchanged Features
Working on the theory that 'if it ain't broken, why fix it', Sony has carried many of the features that made the A100 so attractive on to the new model, sometimes with a bit of tweaking. Like the A100, the A700 comes with "Super SteadyShot inside", a built-in anti-shake function that works with all Alpha lenses. A gyroscope in the camera body detects camera motion and shifts the sensor to counteract it, giving a 2.5-4 stop shutter speed advantage over unstabilised cameras.

The anti-dust system used in the A100 is also replicated in the new camera. Consisting of anti-static coatings in the mirror box plus vibration of the low band-pass filter in front of the image sensor, this system automatically 'buzzes' each time the camera is switched off, so it doesn't affect start-up times (which are almost instantaneous).
The A700 provides the same three metering modes as the A100 and bases them on a 40-zone honeycomb-pattern sensor. However, the sensor in the A700 is a new Silicon Photo Cell (SPC), which has improved sensitivity and a 2.2% centre cell for spot metering.

White balance settings are essentially unchanged, although a little more flexibility is provided for fine-tuning colours in the new camera. Flash modes are also identical to the A100 and, in both cameras the flash guide number is 12. However, the new model has a 1EV wider flash output adjustment range.
A table comparing the differences between the A100 and A700 models is provided below. (A separate table comparing the A700 with its rivals the Canon EOS 40D and Nikon D300 can be found on the Photo Review website.)

Bundled Software
The supplied software bundle includes Sony Image Data Suite, which consists of Image Data Lightbox SR V. 1.0, Image Data Converter SR V. 2.0 and a Remote Camera Control facility that allows the camera to be used with a PC.  Sony Picture Utility, which centres on Picture Motion Browser V. 2.1.02 is also provided.  Image Data Lightbox is primarily an image browser and works with both raw and JPEG files. It allows image files to be browsed, selected, enlarged and rated. You can view up to four images and compare them on-screen or call up screens showing image properties and a small histogram. It also provides easy facilities for creating image collections for special projects and supports batch printing and JPEG/TIFF file conversion.

Image Data Lightbox provides easy side-by-side comparison facilities and users can view a shooting data screen and small histogram.

The main raw file converter/editor is Image Data Converter SR. It provides adjustments for white balance, tone curve, exposure and sharpness and also allows users to set the Creative Style for the image. You can register your favourite image editor as a destination for files to be transferred to after they have been converted to either JPEG format or 8- or 16-bit TIFF files. The user interface is reasonably friendly, once you have sorted out the desktop and minimised the windows you're not using and the application runs quickly enough to meet most photographers' requirements.

The user interface for Image Data Converter SR.

Photographers can re-set the Creative Style for the picture as part of the raw file conversion process.

Standard settings for saving converted images include 8- and 16-bit options for TIFF files. Users can also elect to crop saved images in 16:9 aspect ratio.

Picture Motion Browser is an automatic cataloguing application that organises image files as they are uploaded to your computer, sorting them according to the date of the download. You can opt not to use this facility if you'd rather catalogue your images with a different system, but you can't elect not to load it onto your computer when loading the other applications.

 
Picture Motion Browser provides calendar-based cataloguing and automated uploading facilities.

Performance
Because of its comfortable grip and excellent control layout, the test camera was a pleasure to use and provided fast and accurate autofocusing plus accurate exposures for all the shots we took. The new Quick Navi interface made it easy to adjust camera settings and camera response times were generally fast.

Pictures taken with the test camera were sharp with adequate dynamic range in the default mode and wider than average dynamic range when the Advanced Auto setting was used. The ability to determine the amount of dynamic range adjustment came in hand with contrasty lighting, although occasionally the recovered shadow detail looked slightly posterised when the level 5 setting was used.

Imatest showed the camera to be capable of high resolution but revealed a slight degree of edge softening with the 16-105mm kit lens. Lateral chromatic aberration was negligible and we found no evidence of coloured fringing in shots taken in bright outdoor lighting. Strong backlighting was handled very well by the test camera an flare was well controlled.

Colour accuracy was generally good but, with the default Picture Style setting, Imatest revealed some minor hue shifts in reds and cyan and slightly boosted saturation in purples and orange reds but reduced saturation in yellows and yellow-greens. Skin hues were marginally off the mark. All these problems could be easily corrected during raw file conversion or in editing software.

The white balance system had the usual problems with incandescent lighting but produced excellent colours with fluorescent lights. The tungsten pre-set corrected the orange cast of the incandescent lights almost totally and the manual measurement system produced fully neutral hues under both types of lighting.

We measured an average capture lag of 0.15 seconds, which reduced to instantaneous capture with pre-focusing. In high-speed burst mode, the test camera recorded shots at intervals of just under 0.3 seconds with no sign of slowing after 20 Extra Fine JPEGs at top resolution. Low speed burst mode captured shots at just over 0.3 second intervals. It took 6.43 seconds to clear the buffer memory after a burst of 20 JPEGs and 14.18 seconds to clear the buffer after a burst of 11 RAW+JPEG files. (A Sony 133x 4GB CF card was used for these tests.)

Image noise was remarkably low at high ISO settings, even without the in-camera noise-reduction processing activated. We found slight colour noise at ISO settings between 2500 and 6400 but, at ISO 1600 it was no more obvious than the ISO levels we have found at ISO 400 with some DSLRs we've reviewed. Even at ISO 6400, both pattern and colour noise, though noticeable, were very well controlled and shots taken with this setting would be usable as long as they were not enlarged too much. Long-exposure noise reduction processing subdued both types of noise to some degree but marginally reduced image sharpness. As expected, applying noise reduction processing roughly doubled image processing times.

Flash performance was also very good with the test camera. Vignetting was only just evident when shooting with the built-in flash at the 16mm setting but this had vanished by 24mm. Flash exposures were even across the focal length range of the kit lens and with all ISO settings and the flash had sufficient power to produce correct exposures down to ISO 100. 

Image sensor: 23.5 x 15.6 mm  (APS-C type) Exmor CMOS
Lens mount: Sony Alpha mount (compatible with Minolta A-type bayonet mount)
Focal length crop factor: 1.5 x
Image formats: JPEG, RAW (ARW 2.0), RAW+JPEG
Image Sizes: RAW: 4288 x 2856, 4272 x 2848 JPEG: 4272 x 2400, 3104 x 2064, 3104 x 1744, 2128 x 1424, 2128 x 1200
Image Stabilisation: Image sensor shift
Dust removal: Charge-protection coating + image sensor shift
Shutter speed range: 1/8000 to 30 sec plus Bulb; X-synch at 1/250 sec. (Super Steady Shot off) or 1/200 sec. (Super Steady Shot on)
Exposure Compensation: +/- 3 EV in increments of 0.3, 0.5 or 0.7 EV
Self-timer: 2 or 10 sec delay
Focus system: TTL phase detection via CCD line sensors; 11 AF points
Focus modes: Single-shot, Automatic AF, Continuous AF, Manual focusing; eye-start AF selectable
Exposure metering: TTL full-aperture metering with 40-segment honeycomb pattern SPC sensor; Multi-segment, Centre-weighted and Spot metering
Shooting modes: Auto, Program AE (with program shift), Shutter-priority, Aperture-priority, Manual, Scene selection (Portrait, Landscape, Macro, Sports, Sunset, Night view/portrait)
Picture Style/Control settings: Standard, Vivid, Neutral, Adobe RGB, Clear, Deep, Light, Portrait, Landscape, Sunset, Night view, Autumn leaves, Monochrome, Sepia
Colour space options: sRGB, Adobe RGB
Custom functions: 21
ISO range: ISO 200-3200 (expandable to 100 and 6400)
White balance: Auto, Daylight, Shade, Cloudy, Tungsten, Fluorescent, Flash; Colour Temperature / Colour filter, Custom; bracketing of 3 frames H/L  selectable
Flash: Manual pop-up; GN 12 (metres at ISO 100)
Flash exposure adjustment: +/- 3 EV in increments of 0.3 or 0.5 EV
Storage Media: Dual slot: Memory Stick Duo + CF Type I, II
Viewfinder:  Eye-level pentaprism; 95% frame coverage; approx 0.9x magnification; 21-25mm eye relief
LCD monitor: 3.0-inch TFT  colour LCD, 921,600 dots
Data LCD: displayed on main monitor
Interface terminals: HDMI (type C minijack)), USB 2.0 Hi-speed, Video Out (PAL/NTSC), remote control
Power supply: NP-FM500H (7.2 v) Info-Lithium battery (CIPA rated for650 frames)
Dimensions (wxhxd): 141.7 X 104.8 X 79.7 mm
Weight: Approx. 690 grams (body only)