Sony Alpha A580 review
Sony A580 Review - Performance
Undoubtedly the most significant feature when comparing the A580 to another beginner DSLR is the 7fps burst rate. When testing the system in the highest JPEG quality the rate only started to falter around the 20 shot mark and yet still happily filled up a card hereafter. The Raw + JPEG mode was very similar, happily firing off the same 20 shots before a more severe drop off in pace. Although the buffer filled the camera was ready for use again fairly swiftly, and images could also be reviewed without a huge delay. The mirror slap was fairly audible throughout use of the burst mode, bringing about slight concerns over whether it would attribute to camera motion or hand shake, although there were few serious indications of this during testing.
The A580's movie mode is, in fact, an interlaced rather than progressive capture. This means that the end product has frames comprised of two combined sets of horizontal lines, alternating at a rate of 50 frames per second. This is often considered a step down in quality compared to progressive scan due to possible 'tearing' in fast motion.
Although the A580 operates on a fundamentally different system to the A55, its phase-detection AF system is of a similar ilk for single focus purposes. The camera is able to adjust focus depth reasonably quickly, and thus reduce the amount of time the camera spends hunting for a subject. Although the system is rapid enough in differing light levels those lacking in more obvious contrast proved an issue at times. It was fortunate that the 75-300mm lens used in a number of the tests featured a focus limiting switch, or a number of images would have been entirely out of focus due to the camera failing to locate a focal point.
The A580 differs from a number of DSLRs in a similar price range by having a physical switch to change between the optical viewfinder and Quick AF Live View mode. Although there is a Focus Check Live View, which can be activated via button press, it's not as fully-featured as the full live view mode. A shutter also obstructs the viewfinder, making it far more useful for long exposures than the Focus Check mode, which simply raises the mirror. The LCD screen itself offers an impressive level of detail, being useful in both direct sunlight and at low and high angles thanks to the vari-angle screen. Although there's only vertical alterations possible the feature is still quite useful. The live view mode itself is streets ahead of competitors thanks to the additional sensor that Sony's 'Quick AF Live View' mode offers. It means focusing speeds of a similar speed to when looking through the viewfinder, something that competitor models really can't match up to.
The A580's Full HD 1080i50 movie mode doesn't allow for continuous autofocus while shooting, instead switching by to the AF-S mode regardless of the prior settings. Only the Exposure Compensation can be altered from the available manual settings, alongside the likes of white balance and D-Range are also available. This does mean all of the major alterations are in the hands of the camera's processing engine and automatic exposure control, so switching between lighting conditions leads to a visible graduation in exposure during recording.
As with the Sony compacts a Sweep Panorama mode is available, working in an extremely similar manner by requiring a singular motion to create a stitched image. A 3D mode is also available, saved as an MPO file that can be output to 3DTVs and similar devices, rather than viewed back on the camera itself. When shooting a panorama it's worth bearing in mind any major changes in exposure, as the camera is essentially locked into a fixed setting until the panorama ends.
The A580's battery life readout was accurate thanks to a percentage display and we shot some 1050 shots before it was fully depleted.
All in all the A580 can be a bit of a mixed bag. When shooting at a set distance the burst rate fared well enough, but the autofocus system wasn't always quite up to pace - it can't match the fast-moving action that a pro-spec camera can, for example. On a number of occasions the focal distance traveled throughout the full available range, hunting for a subject before finally settling - again, not ideal for fast-moving action.