Features & Controls

Sony has constructed the α850 using tough, yet lightweight magnesium-alloy materials for the chassis ensuring increased durability. This model is also moisture and dust-resistant, a feature professionals demand, further enhancing the α850's versatility. The camera's outer shell has a smooth black finish, while the hand-grip and thumb rest are wrapped in a comfortable rubber-like material that offers a nice secure grip on the camera with your right hand.

Above we have the front of the camera with no lens attached. In the center you can see the lens mount, which is compatible with all Sony Alpha series lenses, Sony wide- aperture zoom lenses, Sony "G" Series lenses, Carl Zeiss coated lenses, and a plethora of Minolta a-mount lenses. Sony lists 37 lenses on their site, along with 2 teleconverters that are available as optional accessories for Alpha dSLRs. At the top left you can see the AF-assist lamp.

Sony has conveniently positioned the focus mode switch just within reach of you thumb (lower right in the photos above). Which switch allows you to toggle the focus mode from Single, Automatic, Continuous, and Manual. More info on the AF system can be found further down the page.

The A850 utilizes Sony's "Exmor R", full-frame (35mm), CMOS image sensor with 24.6-megapixels of resolution. This unit is 2.35x larger than the typical APS-C sized sensors used on most digital SLRs, which allows the camera to offer increased performance in low-light conditions, better wide angle performance, more fine detail and broader dynamic range. Not to mention this sensor will help provide more control over depth of field (aka range of focus).Specifically designed to match the performance requirements the A850's Exmor R CMOS sensor, Sony has included their proven SteadyShot technology into the camera's body. This means no matter what lens you use, you have an effective IS system in place (on most competitors dSLR models in this class, you have to purchase expensive lenses to obtain this same stability). This system uses sensor-shift technology to compensate for camera movement. It's so effective that Sony claims photographers can shoot at shutter speeds up to 4 stops slower than what they would normally use without any IS system in place.

Another important feature on A850 is Sony's Anti-Dust Technology. When you swap out lenses, tiny particles of dust and debris can enter the body and land on your image sensor. If not taken care of, you will start to see these specs in your photos. The A850's anti-dust system utilizes both an anti-stake indium tin oxide coating on the sensor filter along with vibration that automatically shakes the sensor to dislodge this dust and/or debris. Whenever the camera is turned off, the anti-dust feature is activated.


The A850 utilizes a nice pentaprism, eye-level optical viewfinder which offers a 98% field of view and 0.74x magnification (with 50mm lens at infinity). It also boasts a large 20 mm eye-relief, along with a very comfortable eyepiece cup that is removable/replaceable. If the Eye Start option is enabled, the AF system will activate and the LCD will black out whenever you bring the camera up to your eye (you can see the small sensors under the viewfinder). Sony has included a Type G Spherical Acute Matte focusing screen, which you can swap out for a Type L or Type M unit. Below you can see the differences between each screen.

Type G Standard or Default focusing screen installed at the factory
Type M Makes it easier to check the peak of the focus and approximate sharpness. This is suitable for a brighter lens (F1.4 to 2.8).
Type L Includes a grid. The brightness of the viewfinder is the same as that of the Type G.

Above you can also see the OFF/ON power switch, the Flash hotshoe, and the mode dial.

Above you can see the standard Type G focusing screen, along with it's indicators for the AF points (9-areas), spot metering area, etc. Below you can see a graph that indicates what each icon represents.

The A850 uses the same 9-point AF system that was introduced on the A900. This system offers exceptional accuracy, with 9 "main" AF sensors along with 10 "assist" sensors for wide-area coverage that gives you great flexibility in how you frame your subject. To exercise even more control, you can choose the "Local" AF area mode (available via the Function menu). When enabled, you then use the up/down/left/right buttons on the directional pad to choose any of the nine sensors as a spot-focusing target.

  • Focus sensitivity: 0 to +18 EV (at ISO 100)

Along the of the viewfinder you will see the digital status line that displays flash compensation, flash charging, wireless flash, high-speed sync, manual focus, focus, shutter speed, aperture, EV scale, "shooting unavailable" warning, camera shake warning, steadyshot scale (five indicator bars that show graphically the amount of action being taken by the steadyshot system to counteract camera movement), and aspect ratio 16:9 (when enabled).

Exposure Metering

Exposure metering is handled by the same 40-segment honeycomb pattern metering system we've seen on past Alpha series dSLR models. This system helps the A850 provide optimal exposures in a variety of different shooting and lighting conditions.

Available User selectable metering options include:
  • Multi-segment, Center-weighted, Spot, Auto Exposure Lock (AEL button)
  • Metering range: 0 - 20 EV (2 - 20 with spot metering) at ISO 100 with f/1.4 lens.

sony_f20am_500.jpgThe DSLR-A850 does not offer a built-in flash unit like a consumer level dSLR would. This is a professional level model that requires the use of more powerful external speedlites. The A850 supports Sony's newer HVL-F20AM (as well as the HVL-F42AM, HVL-F56AM, HVL-F36AM, and Minolta MAXXUM 5600HS and 3600HS), allowing you to take advantage of wireless high-speed and TTL flash, rear-curtain flash synchronization, bounce flash and advanced off-camera setups for pro-level flash shooting.

Off-camera flash is possible with the FA-CS1AM Off-camera Shoe and FA-EC1AM extension, FA-MC1AM multi flash and FA-CC1AM Off-camera cables.

Sony DSLR-A330

The Sony HVL-RLAM ringlight (above) and HVL-MT24AM macro twin flash units are for perfectly illuminated close-up photography.

Visitors of Steves can visit the stores below for real-time pricing and availability. You can also find hot, soon to expire online offers on a variety of cameras and accessories at our very own Camera Deals page.