Digital SLR

Sony's DSLR-A850 provides most of the features of the company's flagship full frame DSLR A900, but for $1000 less. The sensor is the same 24.6-megapixel CMOS chip and includes the A900's sensor-shift image-stabilisation mechanism plus Dual Bionz processors. It is also equipped with the same 3.0 inch 921,000-dot transflective Xtra Fine LCD monitor. However, the viewfinder on the A850 provides only 98% frame coverage against A900's 100%.

Although the A850 is targeted at serious photo enthusiasts there is one feature that should cause some buyers to think twice. We may never have discovered it unless Sony's PR company had included a very attractive-looking DT 50mm f/1.8 SAM lens with the review camera. Trying to frame our Imatest test shots with this lens - and ending up with cropped images - sent us to the user manual for further information.

We discovered the answer in the small print below the Recording Menu table on page 104 (and this appears to be the only place it's mentioned as there's nothing in the index to clarify matters). To quote: When attaching a DT lens, APS-C capture is automatically selected. So, although you can use these lenses on the camera body, fitting a DT lens will crop the image to APS-C size (3984 x 2656 pixels - or 11-megapixels), which negates one of the main reasons for buying this camera in the first place.

But that's not all; there are no cropping indicators in the viewfinder - so you're left with a point-and-guess approach to shot composition, even if you want to select the smaller format deliberately. As we found when shooting with the DT 50mm f/1.8 SAM lens, you have no real idea how much of the field of view you've captured until after the shot is taken.

This simply isn't good enough for a camera body costing $3,499. If the camera can accept lenses designed for the smaller sensors, at least users deserve viewfinder settings for framing shots. Other manufacturers have greyed out those parts of the scene that can't be recorded or displayed framing guide. Some advise that lenses designed for smaller-sensor cameras shouldn't be used on their ‘full frame' models.

So, if you already have a collection of DT lenses, the A850 is probably not the camera for you.

Build and Ergonomics
The body of the A850 has the same magnesium alloy chassis and environmental sealing as the A900, although the finish is marginally less refined. Build quality is solid but nothing about the camera body stands out as exceptional. For example, the covers to the memory card and battery compartments are no more solid than those on Sony's entry-level DSLRs.

Front view of the Sony DSLR-A850 with 28-70mm lens. (Source: Sony.)


Angled front view, showing the depth of the grip. (Source: Sony.)


Front view without a lens, showing the mirror box, lens mount and main front panel features. (Source: Sony.)

The grip is generous with a comfortable recess for the middle finger. The sensor for the supplied remote commander is located in this groove. Textured rubber cladding covers the grip and most of the front body panel. The depth of the camera body at the grip won't suit users with small hands but everyone else should find it comfortable and secure. A textured thumb rest is located on the rear of the camera body. 

The large AF-Assist light (which doubles as a self-timer indicator) sits between the grip and the lens and viewfinder housing. The lens mounting is a large, stainless steel plate with six electronic contact pins. Buttons are provided for the Preview (see below) and detaching the lens. On the top right corner of the front panel lies a flash synch terminal with a screw-off cover for external flash connections.

Rear view of the DSLR-A850 showing the Quick Navi screen display. (Source: Sony.)

Covering most of the rear panel is the same 3-inch, 921,000-dot Xtra Fine LCD monitor as used in the A700 and A900 models. This screen is used for most menu-based adjustments and doubles as a 'Quick Navi' screen in association with the Fn. Button. Live View shooting is not supported, although the A850 provides the same Intelligent Preview function as the A900.

Pressing the Preview button records a picture in the internal camera memory. This image can be used to simulate the effect of various camera settings with adjustments to parameters like exposure, white balance and D-Range Optimiser supported. The changes are displayed directly on the monitor. Once the required tweaking is satisfactory, pressing the shutter release button transfers the shot to the memory card. 


The top panel showing the small data LCD and button controls. (Source: Sony.)

The A850 has the same small data display on the top panel as the A900. It's monochrome only and provides status checks for the aperture, shutter speed, exposure compensation, white balance, ISO and drive mode settings as well as a count-down of the number of recordable images and a battery status check. Backlight illumination is available via an adjacent button.

Surrounding this button are four buttons that access the exposure compensation, drive, white balance and ISO sub-menus. Settings contained in these menus are essentially identical to the A900. The mode dial on the opposite side of the top panel is identical to the A900, with Auto, P, A, S and M shooting modes plus three memory banks for registering groups of frequently-used settings.

Rear panel controls are identical to the A900 and include off/on power and stabiliser sliders, a joystick-style arrow pad and buttons for accessing the Menu, Display, Delete, Play, AF modes, AE lock and Custom and Function sub-menus. Front and rear control dials are provided for adjusting aperture and shutter speed settings and you can decide which dial handles which with a setting on page 2 of the Custom menu.

The A850's ground-glass optical pentaprism viewfinder is similar to the finder on the A900 but only offers 98% field-of-view coverage (instead of 100%). It supports 0.74x magnification with a non DT 50mm lens at infinity and approximately 20mm eye relief (which is handy if you wear glasses). The standard Type G focusing screen can be exchanged for optional Type M screens (super spherical acute matte for fast lenses) or Type L screens (which include a grid display). A built-in eyepiece shutter is provided to exclude stray light during long exposures.

As in the A900, the A850 has a hot-shoe but no pop-up flash so we were unable to test flash performance. A slide-on cover protects the contacts while no flash is fitted. Selectable flash modes include Autoflash, Fill-flash, Rear-curtain sync, Slow sync and High-speed Sync. In-camera support is provided for the Minolta-designed ADI flash system, which uses pre-flash TTL metering to calculate the correct exposure. Wireless flash support is also provided for Sony's HVL-F58AM, HVL-F56AM, HVL-F42AM and HVL-F36A flash units but full multi-flash functionality requires at least one HVL-F58AM unit in the set-up. 

Finally, unlike the A900, the A850 comes without a remote control, although it can be used with the RMT-DSLR1 remote control that is bundled with the A900 but is an optional extra for the A850. Another option is the VG-C90AM vertical battery grip, which sells for $599 (RRP).

Controls
It was surprising to find no Live View on the A850 since the implementation of this function on the A380 was so effective and Sony's Quick AF Live View technology provides faster autofocusing than most competitors. It also puts the A850 at a disadvantage against its main competitors, although it's the cheapest ‘full frame' body on the market. The table below compares key features of the A850 with its sister, the DSLR-A900, and Canon's EOS 5D Mark II and Nikon's D700 models.

When you power-up the A850, the standard data display is provided and the control options are the same as on the A900. Pressing the Fn button lets you navigate around this display and select the functions you wish to adjust. Unlike Sony's entry-level DSLR models, the A850 provides neither a graphic display demonstrating the relationships of the exposure adjustments nor a Help Guide to assist novice users. No Scene mode pre-sets are provided either, although there is a green Auto mode that only appears to block access to the ISO Auto Range settings (unlike most full-auto modes that prevent users from adjusting many settings).

There are 13 Creative Style settings:  Standard, Vivid, Neutral, Clear, Deep, Light, Portrait, Landscape, Sunset, Night View, Autumn Leaves, B&W and Sepia. This is more than double the number provided on the A900. However, each setting is similarly tuneable with contrast, sharpness and (where relevant) saturation adjustments of +/- three steps. D-Range Optimiser settings are the same as the A900, with Off, Standard, Advanced Auto and an Advanced Level setting that provides five optimisation levels.

Sensor and Image Processing
We've already covered the sensor technology used in the A850 in our review of the DSLR-A900. It's the same 24.6-megapixel CMOS chip and includes the A900's sensor-shift image-stabilisation mechanism.  Dual Bionz processors work in parallel to process high pixel count image data.

Interestingly, continuous shooting speeds are slightly slower, at three frames/second, compared with five frames/second in the A900. However, this enables the buffer memory to accommodate more shots in each burst, giving the A850 a limit of 34 high-resolution JPEGs or 16 raw files, compared with 11 JPEGs and 12 raw files for the A900.

As in the A900, photographers can choose between compressed and uncompressed raw. However, when RAW+JPEG is selected, the JPEG size is set at Fine by default, instead of allowing users to select between Super-Fine, Fine and Standard JPEG compression. The 16:9 aspect ratio option provided in the A900 has been dropped in the A850.

The raw file format appears to have changed a little since the A900 was released but files from the review camera were able to be opened in Photoshop and Photoshop Elements with the latest iteration (V. 5.5) of the Adobe Camera Raw (ACR) plug-in. Typical file sizes are shown in the table below.

Playback and Software
Pressing the Playback button displays the last shot taken and you can toggle from one shot to the next in either direction with the joystick. The Display button allows you to choose from four display formats: image only, image plus basic shooting data and either of these with a five-frame ‘film strip' above the displayed shot showing previously-capture pictures.

If you wish to display the image with data and RGB plus brightness histogram, this option is selectable by pressing the C (Custom) button. A flashing highlight alert can be selected for the histogram-plus-data playback. Pressing the Fn button toggles between the film strip and a reduced-size playback that can be used for shots that need to be rotated. Pressing the joystick, rotates the shot through 90 degrees counter-clockwise.

Shots can be marked individually or in groups for protection or deletion and you can delete all images in a specified folder or all images on a card. DPOF tagging for automated printing is also available. Owners of HDTV sets can playback shots at ‘optimised Full HD' quality by connecting the camera to the set via an HDMI cable (not supplied). BRAVIA Sync compatibility increases convenience for users with Sony's HDTV sets.

The supplied software disk contains Sony's standard software applications: Image Data Converter SR V. 3.1, and Image Data Lightbox SR V. 2.1, Remote Camera Controller V. 2.0 and Picture Motion Browser V. 4.2.13. We've already covered these applications in our review of the Sony DSLR A900.

Performance
Although we carried out Imatest testing on both lenses supplied with the camera body (which are reviewed separately), because the DT 50mm f/1.8 SAM lens could only produce APS-C-sized shots, all results reported here come from using the review camera with the second lens provided, the SAL 70-200mm f2.8 G lens. With a price tag of $3499, the assumption is of very high-quality optical performance.

Subjective assessment of image quality led us to conclude that the A850 is capable of recording plenty of image detail plus natural-looking colours. JPEG shots were marginally soft straight out of the camera and benefited from a little unsharp masking. Imatest results depended on which lens we used but were comparable with those from the A900, particularly for raw files shot with the 70-200mm f/2.8 G-series lens (which is comparable in price and quality to the lens we used for our tests on the A900).

Imatest showed the camera to be capable of the high resolution expected from a 24-megapixel sensor when the 70-200mm f/2.8 G-series lens was used - but only for ARW.RAW files. When the 70-200mm f/2.8 G-series lens was used for shooting JPEGs, resolution fell slightly below expectations.  
With the DT 50mm f/1.8 lens, our Imatest resolution figures for JPEG files slightly exceeded expectations for a 10.6-megapixel sensor. Raw files were even better. Full details can be found in the reviews of both lenses. (INSERT LINKS)

Imatest also showed saturation to be very slightly higher in the A850 than we found with the A900, although the overall pattern of colour accuracy was quite similar in both cameras, regardless of whether we analysed JPEG or converted ARW.RAW files. As expected, resolution declined gradually as ISO sensitivity was increased. Raw files retained their resolution between at high ISO settings than JPEGs, although we found a significant step down between ISO 3200 and ISO 6400, as shown in the graph below.

Image noise was negligible in long exposures with ISO settings up to 800, where slight softening was detected. It remained low (but visible with 33% enlargement) at ISO 1600, with a slight increase in overall softening. Shots taken at ISO 3200 were usable - but noisy - and shots taken at ISO 6400 were noticeably noise-affected, with both pattern and colour noise clearly visible at 16.7% magnification.

Shooting with long-exposure noise-reduction processing introduced traces of vertical banding and softened details without significantly suppressing image noise. High ISO noise-reduction processing produced even more generalised softening.

Auto white balance performance was similar to the A900. The review camera failed to completely eliminate the colour casts of either incandescent or fluorescent lighting. However both the pre-sets and manual measurement system produced neutral colours and there is plenty of scope for in-camera tweaking of colour balance so this issue is relatively minor.

The built-in image stabiliser enabled us to take hand-held shots that were acceptably sharp with 100% magnification at shutter speeds as slow as 1/10 second with the 70mm focal length setting and 1/15 second with 200mm focal length. We found skin tones (and tonal subtleties) were nicely rendered in the Standard Creative Style and, like the A900, the A850 produced good results in the Monochrome mode, with plenty of detail and excellent gradation - provided exposures were spot-on.

Camera response times were similar to the A900 in our tests. The AF system was quick to lock on to subjects, even in dim lighting after dark. Focusing was accurate for more than 90% of the shots we took, regardless of the drive mode selected. The review camera took approximately half a second to power-up ready for shooting and we measured an average capture lag of 0.18 seconds, which reduced to less than 0.1 seconds with pre-focusing.

We used an ATP Pro Max II UDMA Ready 300x CompactFlash card for our timing tests. Shot-to-shot times averaged 0.4 seconds, regardless of whether we recorded JPEGs or ARW.RAW files. It took two seconds on average to process each JPEG image, 2.1 seconds for each raw file and 2.6 seconds for each RAW+JPEG pair.

In the continuous shooting mode, we recorded nine Large/Extra Fine JPEGs in 2.5 seconds, It took 3.2 seconds to process this burst. A burst of 12 ARW.RAW files was captured in 2.5 seconds and processed in 4.6 seconds, while a burst of 10 RAW+JPEG pairs took 2.8 seconds to record and 6.2 seconds to process.

Buy this camera if:
- You want a solidly-built, competitively-priced DSLR camera with a weather-resistant body and professional-standard controls and functions.
- You want the advantages of a 35mm-sized image sensor.
- You want effective body-integrated image stabilisation.
- You are prepared to pay premium prices for Sony's G-series and Carl Zeiss lenses.

Don't buy this camera if:
- You already have several DT lenses you wish to use on a new camera body.
- You require a Live View shooting mode.
- You would like to shoot HD video clips with your DSLR camera.

IMATEST GRAPHS
JPEG images

Raw images converted in Adobe Camera Raw 5.5

SAMPLE IMAGES

Auto white balance with incandescent lighting.

Auto white balance with fluorescent lighting.

50mm lens at f/4.5; 30-second exposure at ISO 100.


50mm lens at f/16; 30-second exposure at ISO 6400. (No noise-reduction processing.)

50mm lens at f/16; 30-second exposure at ISO 6400. (High-ISO noise-reduction processing.)

Crop from Imatest test shot; 70mm focal length, ISO 6400, 1/160 second at f/5.6.


Showing the effectiveness of the body-integrated image stabiliser: hand-held at 70mm focal length; ISO 400, 1/5 second at f/3.2.


Showing the effectiveness of the body-integrated image stabiliser: hand-held at 200mm focal length; ISO 800, 1/8 second at f/2.8.

Angle-of-view comparison: DT 50mm f/1.8 lens at f/7.1; ISO 100, 1/320 second.

 
Angle-of-view comparison: 70-200mm f/2.8 G-series lens at 70mm and f/11; ISO 100, 1/160 second.

70-200mm f/2.8 G-series lens at 200mm and f/10; ISO 100, 1/400 second.

Additional images can be found with the reviews of the DT 50mm f/1.8 SAM and 70-200mm f/2.8 G-series lenses.

Image sensor: 35.9 x 24.0mm Exmor CMOS sensor with 25.7 million photosites (24.6 megapixels effective)
A/D processing: 14-bit
Lens mount: Sony α lenses, Minolta and Konica Minolta AF lenses
Focal length crop factor: 1x
Image formats: JPEG (DCF 2.0 and Exif 2.21 compliant, DPOF supported), RAW (Sony ARW 2.1 format), RAW+JPEG
Image Sizes: 3:2 aspect ratio - L (24M): 6048 x 4032; M (13M): 4400 x 2936; S (6.1M): 3024 x 2016; 16:9 aspect ratio - L (21M): 6048 x 3408; M (11M): 4400 x 2472; S (5.2M): 3024 x 1704
Image Stabilisation: SteadyShot image-sensor shift mechanism (Approx. 2.5EV - 4EV shutter speed compensation, depending on conditions and lens used)
Dust removal: Charge protection coating on Low-Pass Filter plus image sensor-shift
mechanism
Shutter speed range: 30 to 1/8000 seconds plus Bulb; flash synch at 1/250 sec. (1/200 sec. with SteadyShot on)
Exposure Compensation: +/- 3 EV in 1/3 or 1/2 EV increments
Exposure bracketing: Continuous/Single, with 0.3, 0.5, 0.7, 2.0* EV increments, 3 or 5 frames selectable. (*2.0 EV bracketing limited to 3 frames)
Self-timer: 2  or 10 seconds delay
Focus system: TTL phase-detection with CCD line sensors; 9 points (centre dual-cross type) with 10 assisted points; AF illuminator range 1-7 metres
Focus modes: Single-shot AF, Auto AF, Continuous AF, Direct Manual Focus, Manual Focus
Exposure metering: TTL metering with 40-segment honeycomb-pattern SPC; Multi Segment, Centre-weighted, Spot metering patterns
Shooting modes: Program AE (AUTO/P, with program shift), Aperture priority, Shutter priority, Manual
Colour modes: Standard, Vivid, Neutral, Clear, Deep, Light, Portrait, Landscape, Sunset, Night View, Autumn Leaves, B&W, Sepia
Colour space options: sRGB, Adobe RGB
Custom functions: 5 Dynamic Range Optimiser settings (including off and bracketing); Brightness, Contrast, Sharpness, Saturation and Zone Matching adjustments available in all colour modes
ISO range: Auto, ISO 100-6400 in 0.3EV increments
White balance: Auto, Preset (Daylight, Shade, Cloudy, Tungsten, Fluorescent, Flash), Colour Temperature (2500 - 9900k with 19-step Magenta/Green compensation), custom (3 memories)
Flash: External flash unit; supports ADI/ Pre- flash TTL flash; modes include Auto, Fill flash, Rear Sync, High-speed sync, Slow sync and Wireless with compatible flash 
Flash exposure adjustment: +/- 3EV (0.3/0.5 EV increments)
Sequence shooting: Up to 3 frames per second; JPEG Fine/Standard: 384/593 frames, JPEG Extra fine: 34 frames, RAW: 16 frames, cRAW (compressed): 18 frames, RAW+JPEG: 12 frames, cRAW+JPEG: 12 frames
Storage Media: Dual slots for CompactFlash (Type I/II) and Memory Stick Duo
Viewfinder:  Fixed eye-level system with optical glass type pentaprism and Spherical Acute Matte focusing screen (interchangeable); 98% FOV coverage; 0.74x magnification (with 50mm lens at infinity); approx. 20mm eye relief; -3.0 to +1.0 dioptre adjustment
LCD monitor: 3.0-inch, 921,600-dot, Xtra Fine LCD with 100% field of view
Live View modes: No live view
Video Capture:  No
Data LCD: 19 x 21mm monochrome display
Interface terminals: USB2.0 Hi-Speed (mass storage mode / PTP mode / multi LUN); HDMI mini type C connector; Video out (PAL/NTSC selectable); DC-in; remote terminal adaptor
Power supply: NP-FM500H rechargeable InfoLithium battery (CIPA rated for approx. 880 shots/charge)
Dimensions (wxhxd): Approx. 156.3 x 116.9 x 81.9 mm (body only)
Weight: Approx. 850 grams (body only)