Sony A580 Preview

16.20 Megapixels	Sony Alpha (Minolta A) mount	3.0 inch LCD

Sony A580 Preview

by Mike Tomkins and Shawn Barnett
Posted: 08/24/10

Being announced alongside Sony's attention-grabbing Translucent Mirror cameras, the A33 and A55, the launch of the Sony A580 will perhaps be robbed of some attention -- and that's maybe a little unfair, because when compared to its predecessor, the A580 sports some genuinely useful changes.

The Sony A580 is based around a new 16.2 megapixel, APS-C sized image sensor, which now carries Exmor APS HD branding. (Compared to the A560, alongside which it is also announced, the A580's sensor is really the only difference.) Perhaps the most significant change between the older A550 and the A580, though, is a brand new autofocus system, based around a 15-point AF sensor, of which three are cross-type points. From the fifteen total points, eleven can be addressed directly, and four serve as assist points.

Also new to the Sony A580 is its high-definition movie recording capability, which is fast becoming a common function even among entry-level DSLRs, and an absolute must-have feature for enthusiast cameras. The Sony A580 can record movies at up to 1,920 x 1,080 pixel (Full HD) resolution, with stereo audio -- either from a built in microphone, or an external mic with 3.5mm jack. The A550's Smart Teleconverter button, which simply cropped the image when shooting at lower resolutions, has been abandoned in favor of a new dedicated Movie button.

Sony has also made some useful tweaks to the A580's body design. The Drive Mode and ISO buttons have both been moved nearer to the Shutter release button, making them easier to reach without having to change your grip on the camera. There's also a new Depth of Field Preview button just beneath the right side of the lens mount. The Mode dial is also a little larger, easier to grip, and clicks more firmly between positions so as to prevent accidental adjustment. The various scene modes on the Mode dial have been consolidated into a single Scene position, simultaneously reducing clutter and freeing up room for a new Sweep Panorama position.

Sweep Panorama has appeared in Sony's Cyber-shot and NEX-series cameras previously, and is now making its debut in an Alpha DSLR. The function, which offers 2D and 3D modes, automatically captures numerous images as the A580 is panned across the scene, and then stitches the result in-camera to create a single seamless image. The Sony A580 retains its predecessor's Auto HDR function, where the camera captures two images and merges them into one High Dynamic Range image, but now increases the possible strength of the effect, by doubling the step size to create a total range of up to 6 EV in 1 EV steps. High ISO Noise Reduction has also been adjusted, and now offers a choice of Auto or Weak modes, in place of the previous High or Normal positions. A new Multi-Frame NR function overlays six sequential images in-camera, to create one final exposure with about a two stop improvement in signal to noise ratio.

The A580 retains the articulating display screen from the A550 design, as well as the unusual Live View mode that uses a secondary, low-resolution sensor inside the pentamirror, so that phase detection autofocus can be offered during live view. The AF550's alternative MF Check LV mode -- which raises the mirror and exposes the imaging sensor like the live view modes on most other DSLRs -- has been renamed and greatly improved. It's now called Focus Check LV, and offers not only manual focusing or phase detection AF with a brief interruption to the live view stream, but now also offers contrast detection autofocusing.

A few other notable changes include the addition of an ISO 100 position, slight updates to the Help Guide function and menu system, a change to Sony's new playback mode, which segregates still and video content, support for the latest generation SDXC cards, and the removal of PictBridge support.

The Sony Alpha A580 will be available in the US market from November 2010. Pricing has been set at around $800 body-only, and $900 when bundled with an 18-55mm kit lens.

Look and feel. At first glance, the Sony A580's body is very close in design to that of its predecessor, the A550. Size and weight are unchanged, but on closer inspection, there are a number of relatively subtle changes made to accommodate new features, or improve accessibility of existing ones.

The duo-tone body of the previous design has been replaced with a more professional-looking all-black body, and a slightly more noticeable texture applied all over. It's a change that you'll only notice if you look really closely, and yet somehow it makes less obvious the fact that the A580's body panels are plastic. The shiny black accent strip on the front of the grip, which conceals the infrared sensor and self-timer lamp, has also been given a matte finish along the lower half of its length. Just beneath and to the left of the lens mount in the picture below, you can see the new Depth of Field Preview button.

Like that of the A550, the Sony A580's grip is a little odd. It's rather slim left-to-right, and not really deep enough. This impression is increased by the unusual thickness of the body front-to-back. We really didn't find it very comfortable for long hand-holding. Here you see the switch for Live View, in the same location as past models. The Alpha a550's MF Check LV button, which puts the camera in Live View mode from the main imaging sensor, has been renamed Focus Check LV for the Sony A580. The name change hints at the fact that autofocus is now possible in this mode.

(Note: The picture above shows the AlphaA560, which is externally identical to the A580.) Dynamic Range, Drive mode, and ISO settings can also be adjusted on the top deck, and the latter two buttons have been moved closer to the shutter release, making them easier to reach when a quick adjustment is called for. Note the sloped area between the top and back, making operation a little easier from more angles. Also visible is the reworked Mode dial, which adds a Sweep Panorama position, and consolidates all of the Scene modes into a single shared position. The dial itself is a little taller and easier to grip, has a much stiffer detent, preventing accidental mode changes. The top of the dial has been changed from a smooth, screen-printed metal badge to a plastic one with raised, painted lettering. Also visible from this angle are the two four-hole grilles for the left and right channels of the new stereo microphone, located directly in front of the flash hot shoe.

The back view is nearly identical to the A350, except that the Smart Teleconverter function has been removed, and its button -- now silver with a central red dot -- acts as a Movie shutter button. This allows the movie function to be accessed in any operating mode, although ISO sensitivity, shutter speed and aperture for movie shooting remain under automatic control regardless of the mode currently selected.

As in the A550, the Function (Fn) button calls up the A580's Function menu, allowing quick settings changes for common exposure variables. When comparing the Sony A580 to the A550 from this angle, you can just notice the slight increase to the height of the mode dial. The only other visible change that would tip you off as to which camera you're looking at is the new Movie shutter button. Adopting the traditional design, in silver with a red dot, this button replaces the previous Smart Teleconverter button, and has the same shape and positioning.

The tilting LCD mechanism has the same generous angular mobility as that in the A550, able to tilt a full 90 degrees downward, and a little beyond 90 degrees upward. While it doesn't allow for framing of self portraits, it's very helpful when shooting overhead, or low to the ground. A small sensor on the lower right of the Sony A580's LCD can be set to dim or brighten the LCD's backlight automatically when needed. (The image at right is of the simultaneously announced Sony A560, which is essentially identical in terms of body design).

Looking at the left of the A580's body, you can see the newly added three-hole speaker grille, directly above the forwardmost rubber compartment door. Behind the compartment door is the other notable change from this side of the camera -- a new 3.5mm stereo mic jack, allowing use of external microphones with the A580. Connectivity options behind the other compartment door include high definition video output, and USB 2.0 High Speed data. The Sony A580, like its predecessor, conspicuously lacks any provision for standard definition video output.

Image Sensor. At the heart of the Sony A580 is a new Sony Exmor APS HD CMOS image sensor with dimensions of 23.5 x 15.6mm, roughly equivalent to a frame of APS-C film. The Sony A580's sensor has an effective resolution of 16.2 megapixels, and yields 3:2 aspect ratio images with dimensions of up to 4,912 x 3,264 pixels. In addition to two lower-resolution 3:2 modes of 3,568 x 2,368 and 2,448 x 1,624 pixels, the Sony A580 offers three modes that crop the sensor's output to a 16:9 aspect ratio, suitable for viewing on wide-screen HDTVs. The Sony A580's 16:9 image modes are 4,912 x 2,760, 3,568 x 2,000, and 2,448 x 1,376 pixels respectively.

The imager is mounted on a movable platter, allowing for Sony's SteadyShot INSIDE image stabilization with all compatible lenses. The system is unchanged since the A550, and is said to offer 2.5 to 4 stops of correction. The sensor-shift mechanism is also used to shake dust from the sensor, as part of Sony's Anti-Dust system which also includes a charge protection coating on the low-pass filter. Output from the image sensor is handled by Sony's proprietary BIONZ image processor.

Noise Reduction. The Sony A580 uses a combination of on-sensor noise reduction at each photocell location, plus a two-step noise reduction procedure which operates both before and after analog-to-digital conversion, processing chrominance and luminance noise separately. The result is an unusually wide sensitivity range, from a minimum of ISO 100 to a maximum of ISO 12,800 equivalents, in 1 EV steps. Settings from ISO 100 to 1,600 are available under automatic control.

High ISO noise reduction is applied at sensitivities of ISO 1,600 or above, with auto or weak strength options available, rather than the A550's high or normal strength options. Long exposure noise reduction is also available at shutter speeds longer than one second, and can be disabled at the photographer's option.

Multi-Frame NR. The Sony A580 also includes a new Multi-frame NR function, which captures six images in sequence, and then combines them in-camera into a single image with reduced noise levels. When enabled, sensitivities from ISO 100 to 25,600 equivalents, plus an Auto ISO function, can be selected. The function is similar to Sony's Handheld Twilight mode -- which the A580 also offers -- but differs in allowing the desired ISO sensitivity to be selected manually, so it can function even at lower sensitivities. Of course, since it involves multiple exposures, it's only of use with relatively static scenes.

Autofocus. The Sony Alpha A580 offers an overhauled TTL phase detection autofocusing system, which now provides 15 AF points, six more than in the A550. Of these 15 points, three are cross-type points, sensitive to both horizontal and vertical detail. Only 11 of the 15 points are available for manual selection, with the remaining four points not directly addressable, and used only when the camera is set to automatically select the AF point. The new AF sensor has a slightly wider sensitivity range of -1 EV to +18 EV at ISO 100 equivalent, versus the 0 to +18 EV range of the A550.

Like its predecessor, the Sony A580 includes an AF-assist lamp to help with focusing in low-light conditions. Thanks to a secondary image sensor in the A580's prism assembly, Sony is able to continue using the standard phase-detection AF system while displaying a Live View image on the camera's LCD display. Dubbed Quick AF Live View mode by Sony, this is reminiscent of a system that was used in Olympus' EVOLT E-330 digital SLR, but with the addition of some current technologies.

For example, in Quick AF Live View mode, the Sony A580 is able to offer face detection when focusing with the phase-detection sensor. When a face is detected, the camera can automatically select the correct AF point, and adjust exposure, white balance, flash output, and other variables to ensure that your subject's face is correctly rendered. The extra information from the face detection system also allows an improved AF tracking function. The Sony A580's face detection system also allows a Smile Shutter function, which can automatically trigger the camera's shutter immediately when your subject smiles. The animation at right, courtesy of Sony Electronics, is from our A550 review. The function works similarly on the A580.

Focus Check LV. Alternatively, the Sony A580's Live View can function in Focus Check live view mode, accessed via a dedicated button on the camera's top panel. Previously called MF Check LV in the A550, the new name hints at a feature change. Unlike the equivalent mode in the A550, either contrast detection or phase detection autofocusing is now possible in this mode, as well as manual focusing. (The AF type is selected through screen 2 of the Record menu.) When activated, the camera displays a full-frame view of the scene on the LCD display, using information streamed from the main image sensor, and with the signal boosted if necessary to see the subject in poor lighting. Holding in the AF button, or keeping the Shutter button half-pressed, will trigger either a phase detection AF cycle (with a brief interruption to the live view stream), or a contrast detection cycle. The latter is rather slower, and hence only suited to static subjects but can be more accurate, depending on the subject type. The autofocus mode is locked to single whenever Focus Check live view is active. Pressing the Enlarge button then cycles through 7x or 14x magnified views, useful for confirming accuracy of or adjusting manual focus. Grid lines can also be overlaid on the display to help in precise alignment of the scene. The sensitivity range for contrast detection autofocusing is -2 EV to 17 EV at ISO 100 equivalent, using an F1.4 lens.

Movies. Also new to the Sony A580 is its movie recording capability, fast becoming a common function even among entry-level DSLRs, and an absolute must-have feature for an enthusiast camera. Sony has provided three choices for movie resolution, recorded in one of two formats. For high definition fans, there's a 1,920 x 1,080 pixel, interlaced AVCHD mode, saved at 59.97 fields per second with a bitrate of 17Mbps -- commonly known as Full HD or 1080i. Note, though, that the interlaced stream is actually constructed from sensor data clocked at 29.97 frames per second. There's also a 1,440 x 1,080 pixel, progressive scan, 12 Mbps MP4 mode recorded at 29.97 frames per second, which qualifies as high definition, although it uses a non-standard pixel size. Finally, there's a standard-def 640 x 480 pixel, 3Mbps MP4 mode which is also recorded at 29.97 frames per second. All these field/frame rates are applicable to cameras with NTSC video output. For PAL cameras, the 1080i mode uses 50 fields per second from sensor data clocked at 25 frames per second, and lower resolutions are also recorded at 25fps.

The A550's Smart Teleconverter button, which simply cropped the image when shooting at lower resolutions, has been abandoned in favor of a new dedicated Movie button, which starts and stops recording with consecutive presses. Like many video-capable DSLRs, the Sony A580 provides no direct manual control over video exposure, with the ISO sensitivity, shutter speed, and aperture all selected automatically, regardless of the operating mode currently selected on the Mode dial. A degree of control is available during video capture through the auto exposure lock and exposure compensation functions, however, and variables such as white balance and creative styles can be set before video capture commences. It's also not possible to use autofocus during movie recording, so use of a smaller aperture to increase depth of field is recommended, unless shooting static subjects, or you're particularly adept at pulling focus manually.

Movie audio is recorded using a built-in stereo microphone, whose two tiny four-hole grilles can be found directly in front of the flash hot shoe, at the base of the popup flash. The A580 also accepts an external stereo microphone, thanks to a 3.5mm microphone input behind a rubber panel on the left side of the body. Directly above this is a three-hole grille for the A580's internal, monaural speaker. It's also possible to disable audio recording altogether, if desired.

Modes. The Sony A580 includes Auto, Program, Aperture- and Shutter-priority, and Manual shooting modes plus Sweep Panorama, Scene, and Flash Off modes. Unusually for a camera at this price point, the A580's Program mode lacks a Program Shift function, which would allows selection of different shutter speed / aperture combinations while maintaining the metered exposure -- an oversight shared with the previous A550 model.

The Sweep Panorama mode is has appeared in Sony's Cyber-shot and NEX-series cameras previously, and is now making its debut in an Alpha DSLR. The function, automatically captures numerous images as the A580 is panned across the scene, and then stitches the result in-camera to create a single seamless image. Both 2D and 3D modes are offered, with the latter mode separately considering the relative positions of subjects as they pass the left and right side of the frame, and then using this information to render separate images with left and right views. The result is saved as a multi picture object (MPO) file, containing both images with JPEG compression. This multi-picture file can be viewed in 3D displays such as Sony's latest Bravia 3D HDTVs. 2D Sweep Panoramas can be created at resolutions up to 12,416 x 1,856 pixels horizontally, or 2,160 x 5,536 pixels vertically. 3D Sweep Panoramas can only be captured horizontally, and with a maximum resolution of 7,152 x 1,080 pixels.

The selection of Scene modes, which help beginners get the results they desire with a minimum of effort, are now all accessed from a single position on the Mode dial. A total of eight Scene modes are available -- one more than in the previous A550 model -- and these include Portrait, Sports Action, Macro, Landscape, Sunset, Night View, Hand-held Twilight, and Night Portrait. Previously seen in Sony's NEX and Cyber-shot series cameras, the Hand-held Twilight mode captures multiple shots at high sensitivity, and then combines them in-camera to create a single image with reduced blur from camera shake. Available shutter speeds from the Sony A580's electronically controlled, vertical travel focal plane shutter range from 1/4,000 to 30 seconds, plus a bulb mode, and flash sync is available at 1/160 second.

Metering. The Sony A580 uses a 40-segment honeycomb-patterned SPC sensor to determine exposures in all modes except for Quick AF Live View and Focus Check Live View modes, where the secondary image sensor can be used to provide for more accurate 1,200-zone evaluative metering.

Metering modes available in the Sony A580 include Multi-segment, Center-weighted, and Spot. 2.0 EV of exposure compensation is available in 1/3 EV steps, and the Sony A580 also allows for three-shot bracketed exposures in 0.3 or 0.7 EV steps. White balance modes include Auto, six presets (Daylight, Shade, Cloudy, Incandescent, Fluorescent, or Flash), and manual white balance -- including the ability to specify a color temperature. Three-frame white balance bracketing is also available, with two strength levels possible.

User interface. The Sony A580 retains Sony's excellent menu system largely unchanged, except for the addition of two new tabs, covering storage and clock settings, respectively. The Sony A580 also retains the A550's Function menu, with simple icons that line the screen left and right. The A580's Playback mode adopts the newer design from Sony's NEX-series single-lens direct view cameras, which is peculiar in that you can't review both images and videos at the same time. Playback confines the list of available items to whatever you shot last. That is, if you've been shooting stills and movies, and the last thing you shot was a still, when you press the Playback button you'll only see still images. To see movies, you have to switch to Movie mode, or else a quick movie. You can also hit the Menu button, select the Playback menu item, and scroll down to Still/Movie Select, press that menu item, then select between Still and Movie on a separate screen.

Sony's user-friendly Help Guide Display is active by default, and shows a brief explanation as the Mode dial is turned, or when the active menu selection is changed. To reinforce the message for operating modes, Sony has added vivid example pictures that appear in the background of the A580's operating mode Help Guide displays, indicating for example that Manual mode might be appropriate for fireworks photos, and shutter priority to blur motion in a waterfall. In menus, a short time after the current selection is changed, a brief explanation of the newly highlighted item fades into view. You press the center button to make your selection, and you're taken to a submenu where the same basic help menu helps you understand the meaning of each item in plain text. When you're sufficiently versed on the controls (or sufficiently annoyed with the Help Guide Display) you can turn it off in Settings menu 1.

Flash. The Sony A580's built-in popup flash has a guide number of 12 meters at ISO 100, and 18mm coverage. Flash modes include Auto, Fill, Slow-sync, and Rear-sync, and 2.0 EV of flash exposure compensation is available in 0.3 EV steps. An intelligent hot shoe is compatible with Sony's HVL-F36AM, HVL-F42AM, HVL-F56AM, and HVL-F58-AM strobes, and high-speed sync / wireless flash are available with these units. Flash metering modes include ADI (Advanced Distance Integration) and Pre-flash TTL, and the internal flash has a recycle time of four seconds.

Auto HDR. Like the A550 before it, the Sony A580 includes an unusual HDR mode. High Dynamic Range photos are created by combining two shots of varying exposure, allowing a greater dynamic range than can be captured in a single exposure.

The interactive animation above, from our Sony A550 preview, shows how Auto HDR works. Just click on the link to open the animation, then work the controls. Animation courtesy of Sony Electronics USA.

Sony's HDR mode captures two shots with anywhere from 1 to 6 EV between the exposures, set in 1 EV increments -- double the overall range of the A550, but with half the granularity. An Auto HDR mode selects the appropriate range and step size automatically, depending on the range of brightness detected within the scene. The Sony A580 can also micro-align the source images in-camera, which means handheld HDR shooting is possible, and the stitching process requires only two seconds of processing per HDR image.

DRO. The Sony A580 also includes Sony's optional D-Range Optimizer function, which works from a single shot and hence isn't limited to static subjects. A function of Sony's BIONZ processor, D-Range Optimizer can function automatically or in one of five manual strength levels, and adjusts the tone curve to avoid blown highlights and blocked shadows.

Creative Styles. The Sony A580's Creative Style function offers six pre-defined creative image styles, which adjust image tonality, saturation, and contrast. Creative Style modes include Standard, Vivid, Portrait, Landscape, Sunset, and B&W, and these can be fine-tuned to the user's preferences.

Continuous shooting. Burst shooting is possible at five frames per second when using the optical viewfinder. When in Live View mode, this is reduced to three frames per second -- a full frame per second slower than in the A550. A Speed Priority burst mode locks exposure and focus from the first frame, which allows an impressive seven frames per second when using either the viewfinder or Live View mode.

Burst depth is also significantly changed since the A550. The Sony A580 is limited to approximately 22 Raw frames in a burst, eight more than the A550. The increase is even greater when shooting in Large / Fine JPEG mode, where the buffer depth climbs from 32 to 44 frames. Strangely, the Large / Standard JPEG mode, is the exception, though, with burst depth is slashed from 116 images to just 45. Finally, when shooting in Raw+JPEG mode, burst depth is nearly tripled to twenty frames.

Storage. The Sony A580 can store images as Sony ARW 2.2-format Raw or EXIF 2.3-compliant JPEG files, with both formats using newer versions of their respective specification than in the A550. The A580 is also able to save each image in both formats simultaneously. Both sRGB and Adobe RGB color spaces are available. Images are stored on Secure Digital cards including the higher-capacity SDHC and SDXC types, or on Sony's own Memory Stick PRO Duo or PRO-HG Duo cards. A small switch is used to select the active card.

Ports. The Sony A580 includes an HDMI Type-C mini connector which allows display of images on high-definition displays (though no cable is included), as well as USB 2.0 High-Speed computer connectivity. One slight change here is that Sony seems to have dropped PictBridge support, which enabled earlier Alpha cameras to be connected directly to a PictBridge-compliant printer, allowing creation of prints without removing the memory card or using a computer. Composite video output is also not provided. There's also a remote port for the optional RM-S1AM or RM-L1AM Remote Commanders, a 3.5mm jack for an external stereo microphone, and a DC input jack for use with an optional AC adapter.

Power. Power is supplied by the same proprietary Sony InfoLithium NP-FM500H lithium-ion rechargeable battery that was used in the A550, but battery life has been improved noticeably. According to CIPA testing standards, the A580 is rated for 1,050 shots when using the optical viewfinder, or 560 shots in Live View mode -- an additional 100 shots with the viewfinder, or 80 shots in live view. The A580 also accepts the same portrait / battery grip as the A500 and A550, which is pictured at right.

Analysis. Overall, it seems the upgrades to the Sony A580 are sufficient to help it better compete with other digital SLRs on the market, most of which now feature some kind of video mode and more advanced low-light capability. The Depth-of-field-preview button is also an important inclusion, heretofore conspicuously absent from the A200, A300, and A500 Alpha models, and its return is welcome for both video and still shooters. Slick tricks like Sweep Panorama and Handheld Twilight are quite useful modes that have worked their way up from Sony's pocket cameras, then into the NEX series, and are now found in the new SLT line and A580. The Sony A580 looks like a good choice for the intermediate photographer who wants to try some of Sony's helpful features with the improved image quality we first saw in the Sony NEX cameras.