Sony Alpha A900

	Hardware Summary
• The full-frame 24.6-megapixel sensor offers the highest resolution in its class • Excellent optical viewfinder provides nearly 100% coverage • Handsome 3-inch LCD with 921,600-dot resolution • Monochrome LCD is small and not terribly useful • Lacks pop-up flash • Long battery life
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Sensor (3.00)

The full-frame CMOS image sensor measures 35.9 x 24.0 mm, with 25,720,000 gross pixels and 24,610,0000-pixel effective resolution. That puts it ahead of its primary full-frame competitors in The Great Megapixel Race, with the Canon 5D Mark II at 21.1 megapixels and a paltry 12.1 megapixels for the Nikon D700.

The A900 incorporates an automatic dust reduction system that shakes the sensor itself (already motorized to provide in-camera image stabilization) every time you turn off the camera.

The A900 sensor matches the 36 x 24mm dimensions of a frame of 35mm film, which avoids the apparent magnification that takes place when you mount a lens on a typical digital camera, with its smaller image sensor. With a smaller sensor, only the middle portion of the light coming through the lens is captured — basically the center becomes the entire photo. As seen below, the APS-C camera sensor used in most digital SLRs effectively multiplies the apparent lens size by a factor of 1.6. For the 24-105mm mm lens we used to test the A900, it would shoot like a 38-168mm lens. That means more telephoto zoom out of the same lens, but also crops out the wide-angle areas. With the A900 and other full-frame SLRs, you get the full side-to-side, top-to-bottom coverage the lens is capable of delivering.

Sensor Size Comparison

A full-frame sensor allows a wider panoramic image from a given lens.

Viewfinder (10.25)

The viewfinder offers nearly 100% coverage, a true standout feature, with excellent brightness and easy legibility for the data readout. The diopter control (-3.0 to +1.0 m^-1) is located on the right of the viewfinder. There's a built-in viewfinder shutter, to prevent light leaking in when shooting on a tripod, a huge convenience compared to mounting a cover manually over the eyepiece. The control for this is on the left of the viewfinder. The A900 supports interchangeable focusing screens, including Type M screens that support very fast lenses and Type L screens that are equipped with a grid pattern.

A sensor below the viewfinder turns the LCD on and off.

Beneath the viewfinder are sensors that automatically turn off the LCD monitor when you hold the camera up to your eye.

The viewfinder displays the following information:

Spot focus area

16:9 image area

Focus points

Spot metering area

APS-C image area

Flash comp.

Flash charging

Camera shake warning

Wireless flash

AE lock

Aperture

High-speed sync

Shutter speed

Shots remaining

Exposure comp.

Focus

Aspect ratio

Manual focus

LCD (8.86)

The standard for fine viewing in an upscale digital SLR today is a 3-inch LCD with 921,000-dot resolution, which is precisely what Sony delivers here. It's a handsome display when viewed straight on, though it does begin to gray out noticeably when held away at a moderate angle — not unusable, but not as wide-angle as the Canon 5D Mark II or Nikon D700.

LCD brightness can be adjusted in 11 steps. Sony was clever enough to display a grayscale chart on the brightness adjustment screen, which makes switching settings a lot more meaningful.

The rear screen menu display can be set to one of three modes by pressing the DISP button during shooting.  The Detailed Display provides an overview of most camera settings (see illustration below).

AE lock

Shooting mode

Shutter speed

Aperture

Exposure compensation

Exposure reading

ISO

Drive mode

Metering mode

D-Range optimizer

Focus mode

AF area

White balance

Creative style

Image quality

Memory card

Battery level

Image size

Images remaining

The enlarged display cuts down on the level of detail, but makes it more readable at a glance.

Finally, pressing the DISP button a third time turns the display off.

One handy feature not found in competitive models is the way the A900 automatically senses when the camera is turned vertically (with either side on top) and swaps the screen display orientation to match.

The rear display reorients itself automatically
when the camera is held vertically.

LCD Panel
While the main LCD panel is a thing of beauty and a joy forever, the monochrome LCD on the top right seems like a begruding afterthough. It's small (only about an inch measured diagonally), with a minimal amount of information displayed. At least the button to the screen's right illuminates it effectively.

The mono LCD display is small and disappointing.

Flash (3.00)

Sony apparently decided that, in line with its professional-grade features and pricing, they wouldn't include a pop-up flash in the A900 design. We may be snobs in certain regards, but we have to admit that the convenience of having a built-in flash still appeals to us. On the plus side, at least there's a built-in autofocus assist lamp: the Canon EOS 5D Mark II leaves that task to the external flash unit.

No pop-up flash to be found,
just a hot shoe to be filled.

Using external flash, six flash modes are supported:

Flash Modes
	Auto Fires when the scene is dark or the subject is backlit. Available only when shooting in AUTO mode.
	Fill-Flash Fires with each shot, regardless of the lighting conditions.
	Rear sync Fires at the end of the shutter release, creating a trailing effect when shooting at slow shutter speed with flash.
	Slow Sync Unlke the other flash modes, Slow Sync is selected by holding the AE Lock button while shooting. Slow sync allows recording of both a foreground subject and background in dark settings.
	High Speed Sync When using flash models HVL-F58AM, HVL-F56AM, HVL-F42AM and HVL-F36AM, high-speed sync allows shooting with flash with the entire shutter speed range of the camera.
	Wireless Requires an optional HVL-F58AM flash unit, which can then control multiple additional flash units wirelessly, including models HVL-F58AM, HVL-F56AM, HVL-F42AM and HVL-F36AM

Lens Mount (8.50)

The A900 is fully compatible with all alpha-series lenses and older Minolta A-type bayonet mount lenses (including the MAXXUM and
DYNAX series). DT-series lenses, built specifically for APS-C-format cameras, can be mounted, and the camera will automatically switch to an appropriate frame capture size when it detects a DT lens, but in many shooting situations there will be visible vignetting in the corners.

Sony acquired the Minolta lens format when it bought the company's SLR operations.

The A900 is not sold in a kit configuration. For test purposes we shot primarily with the TK, which produced the following levels of magnification at the minimum, maximum and middle zoom settings.

Zoom Ratio Examples
24mm	65mm	105mm

Battery (9.00)

The A900 is powered by a NP-FM500H rechargeable lithium-ion battery. Sony estimates that the maximium number of shots per charge is 880, following CIPA testing standards, which is quite high but seems justified based on our shooting experience: Sony does know how to make high-quality batteries.

It will take 235 minutes for a fully depleted battery pack to be fully charged, according to Sony.

Sony consistently produces long-lasting batteries, and the A900 is no exception.

Memory (5.50)

Sony loves to sell its proprietary Memory Stick format, but that doesn't mean the realities of the market are lost on them. The A900 will accept both Memory Stick Duo (up to 16-gigabyte capacity) and CompactFlash formats simultaneously.

The A900 supports both CompactFlash and Memory Stick formats,
one at a time or simultaneously.

Jacks, Ports & Plugs (4.50)

The most noteworthy input/output feature of the A900 is the mini HDMI jack for connecting directly to a high-def TV. It's located on the left side of the camera back, in a compartment that also provides a proprietary jack for standard-definition video and USB data connection.

On the right side of the camera are two additional jacks, under separate covers. The top one is used to connect a wired remote control, the bottom for the optional AC-VQ900AM AC adapter ($150).

There is also a flash sync terminal on the front right of the camera, and an infrared remote sensor on the front camera grip for the included Remote Commander remote control.

Other Features (3.00)

Remote Commander. Most SLRs are compatible with wireless remote controls, but this is the only one we can remember that actually ships with a fully functional remote as a standard feature rather than an added-cost option. The Remote Commander is small — roughly 3.6 x 1.6 x 0.4 inches (91.4 x 40.6 x 10.2mm) — and easily pocketable. It's useful while shooting, of course, with both an immediate shutter release and 2-second timer button (when the camera is set to Bulb, either button starts the exposure with a press, and stops it with a second press). In playback mode, the remote offers nearly all the functions found on the camera itself, including browsing from image to image, enlarging and reducing image display, starting a slideshow and even bringing up a histogram overlay. This capability is great if you've connected your camera to a TV and want to show off your photos in style from across the room.

This little wireless remote
is very handy extra.

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Sony A900 Digital Camera Review Navigation
Intro	Product Tour	Color	Noise
Resolution	White Balance	Sample Photos	Playback
Hardware	Controls	Design & Handling	Speed & Timing
Canon 5D Mark II Comp	Canon 50D Comparison	Nikon D90 Comparison	Nikon D700 Comparison
Conclusion	Specs & Ratings