Sony Alpha DSLR-A580 Review
The A580 was launched at the same time and as the SLT-A55 and, from a specification point of view, they feature pretty much identical video modes. However, while the SLT-A55's translucent mirror design and full-time live view simplify the implementation of a video mode the A580 is a 'traditional' DSLR, which needs to flip its mirror out of the way before it can start recording. So while the A55 can use its phase-detect AF sensor for focusing during video recording, the A580 doesn't allow you to focus during recording at all, neither in phase-detect nor contrast-detect live view AF modes.
Like the A55 the A580 offers 1080i video in AVCHD format (which offers excellent quality with efficient compression and is most suitable for viewing on a HD television set) or 1440 x 1080 pixels in the less efficient but more readily sharable MPEG-4 format. Despite the pixel count the MP4 video is still captured in the 16:9 aspect ratio and is usually interpolated up to 1920x1080 when played back, so doesn't appear stretched or squashed.
The camera can record clips up to 29 minutes long (but only around 14 minutes if SteadyShot is turned on, depending on the ambient temperature). Due to the constraints of memory card file systems, MP4 video can only record files up to 2GB in size, while the AVCHD system can split videos across multiple files to circumvent this limit.
In AVCHD mode the A580 offers high quality HD video capture at 1920 x 1080 pixels (1080p) at 25/30 frames per second (depending on whether your camera is a PAL or NTSC model), though the files are doubled up to 1080i at 50/60 fps for HDTV compatibility. If you record your videos in MPEG-4 format you can also choose a smaller VGA video size.
The built-in microphone captures stereo audio but you can also connect an optional external stereo microphone to provide greater directionality and isolation from lens noise. There is a small built-in speaker for video playback in-camera.
1920 x 1080, 1080i (60/50fps), Av. 17Mbps
1440 x 1080, 1080p (30/25fps), Av. 12Mbps
640 x 480 (30/25fps)
|Audio||• Dolby Digital Audio
• Stereo audio capture via optional external mic.
|Format||AVCHD / MPEG4|
|Bit rate||2.43 MB/sec (1080i AVCHD), 1.65 MB/sec (1440 x 1080 MPEG4)|
|Max file size per clip||2.0 GB for Motion JPEG, card capacity for AVCHD (new file is created automatically after file size has reached 2.0 GB)|
|Recordable time||Approx 29 minutes (around 14 min with SteadyShot enabled)|
Using Movie Mode
Capturing a movie on the Sony DSLR-A580 is a straightforward affair and a very similar process to the A55. Just press the red movie button, no matter what shooting mode you are in, to start and stop recording. The A580's movie mode lacks manual control over shutter speed and aperture (however, you can fix the aperture before you start recording) but nevertheless still offers some scope for creative control. You can apply exposure compensation while creative styles, white balance, AF area and metering mode are all taken over from the current stills image settings. In the menu there are only three movie options to be found - you can select the recording format and size, and deactivate audio recording.
In contrast to the A55 the A580 does not offer AF during video recording. Your only options are pre-focusing before you start recording or manual focus. This is not necessarily a disadvantage. Using AF in video mode can lead to visually unpleasant 'focus jumps' and the noise of the focus motor can often be heard on the audio track. Although the latter can be avoided by using an external microphone, due to the narrow depth-of-field of an APS-C sensor camera, even small shifts in focus will be much more visible than on small-sensor camcorders or compact cameras.
The A580's hinged screen is definitely a big plus for video shooters. Flipping it up allows you to hold the camera lower and use the screen almost like a waist-level finder on a medium-format camera. This posture is considered more stable by many videographers and, together with the camera's efficient SteadyShot systems, allows for very smooth handheld panning.
There is one point of criticism though. Like on most DSLRs the aspect ratio in video recording (16:9) is different to the A580's still images (3:2). However, the Sony only switches to the 16:9 framing (by introducing black bars at the top and bottom of the screen) once you press the movie button and start recording. There's no way of previewing the video frame before recording and you have to pretty much guess if your subjects will fit into the frame. It's less of a problem once you get used to it but nevertheless far from ideal.
Movie mode displays
|There are only three movie options in the menu: you can set movie format and size and switch audio recording off.||The standard movie screen displays basic recording information including remaining time and exposure compensation.|
|There's an option with additional shooting information...||...and the digital level gauge.|
Video quality comments
The A580 captures excellent quality screen-filling 1080p video footage. The motion is smooth and there are no visible artifacts. In low light some noise appears but it's not worse than on any of the competitors. There is also no discernible quality difference between the MPEG-4 and AVCHD formats.
The Sony DSLR-A580's sensor is APS-C size and therefore you can't quite create the same depth of field effects as on a full-frame-camera such as the Canon EOS 5D Mark II but you still get a much shallower, more cinematic depth of field (and much better image quality) than most camcorders or any digital compact camera can offer.
The A580 has built in stereo microphones and the option to add an external stereo microphone. We did not have a chance to test the latter but experience tells us that an external microphone a very useful accessory if you plan on recording 'serious' video with sound. The built-in mic is pretty sensitive and though the sound quality is perfectly acceptable it's not directional enough and also a little prone to capturing wind noise (as you can hear on some of the sample videos below).
Like pretty much all other video-capable large-sensor cameras the SLT-A580 suffers from distortion caused by its rolling shutter. The readout of the sensor means horizontal lines of the image are scanned, one after another, rather than the whole scene being grabbed in one go. The upshot is that verticals can be skewed if the camera (or the subject) moves too fast - the top of the image has been recorded earlier than the bottom, so vertical lines can be rendered as diagonals. The effect is little more noticeable on the A580 than on some other recent DSLRs but it only really becomes problematic when you are panning quite quickly.
Overall the A580's video mode delivers good quality output that is far better than anything you'd get from a digital compact camera. Despite the lack of control over shutter speed, with an external microphone, the necessary technique and some post-processing/cutting expertise you're ready to shoot your own little blockbuster. Below you'll find some examples of videos taken with the camera for you to download and draw your own conclusions.
Caution: very large files
Sample video 1
|1920 x 1080, 50 fps, interlaced, AVCHD, .MTS file, 29 sec. 57.4 MB Click here to download original .MTS file|
Sample video 2
|1920 x 1080, 50 fps, interlaced, AVCHD, .MTS file, 11 sec. 20.9 MB Click here to download original .MTS file|
Sample video 3
|1920 x 1080, 50 fps, interlaced, AVCHD, .MTS file, 10 sec. 19.5 MB Click here to download original .MTS file|
Sample video 4
|1920 x 1080, 50 fps, interlaced, AVCHD, .MTS file, 10 sec. 20.9 MB Click here to download original .MTS file|
Sample video 5
|1920 x 1080, 50 fps, interlaced, AVCHD, .MTS file, 13 sec. 25.9 MB Click here to download original .MTS file|
Sample video 6
|1920 x 1080, 50 fps, interlaced, AVCHD, .MTS file, 12 sec. 24.1 MB Click here to download original .MTS file|