The Sony DSLR-A580 is overall a fast and responsive camera that feels swift and positive in general use. The AF system is very precise and speedy for this class of camera and the power-on time is almost instant. Even in live view mode, thanks to Sony's unique dual live view system, things do not slow down considerably. Only when you need the more precise and better quality preview image of the Focus Check live view mode will you have to make do with the considerably slower contrast detect AF system.
The 7 fps 'Speed Priority' continuous shooting mode locks exposure and focus before the first shot and is therefore of limited use in many situations. Nevertheless, the 'Hi' mode's 5 fps are still a very good value in this sector of the market. Only after the buffer has run full you find yourself in a rare situation, waiting for the camera while it's flushing large amounts of data through its pipelines. It can take up to 30 seconds to clear the buffer, so a fast SD card is recommendable if you plan on doing a lot of continuous shooting.
The camera uses the same SteadyShot image stabilization system that we have seen, and tested on previous Sony Alpha DSLRs. It performs quite efficiently and gives you you a 2-3 EV advantage across all shutter speeds. Especially at slow shutter speeds your chances of getting a sharp shot increase dramatically with the system turned on. It's also very useful at keeping things steady when shooting handheld video.
Continuous Shooting and Buffering
The A580 features a 7 frames per second continuous shooting mode. This sounds, on paper quite impressive for a camera in this class but in the so-called speed priority drive mode the camera locks focus and exposure before the first shot which makes this mode less useful for many applications.
Apart from that, there are also more standard 5 (Hi) and 3 (Lo) frames per second continuous modes. The Hi mode is not available in live view and the Lo mode is not available in focus check live view though. In Hi mode you can capture a decent number of frames before the buffer runs full, no matter what image quality you are shooting in, but, like in Speed Priority mode, the recovery time can be quite long and prevents you from doing other things with the camera while you wait for the red read/write light to go off. It makes sense to invest in a fast memory card if you are planning on using the A580's continuous modes a lot.
With a fast SD memory card the Lo mode gives you unlimited frames (until the card runs full) at 3 frames per second in JPEG Fine mode. Here's how the A580 performs with a 8 GB Panasonic Class 10 card installed.
7fps (Speed Priority):
- JPEG (Fine): around 7 fps for 33 frames then about 1.7 fps
- RAW: around 7 fps for 20 frames, then around 0.9 fps
- RAW + JPEG: around 7 fps for 19 frames, then about 0.7 fps
- Recovery time: around 15-30 seconds
- JPEG (Fine): around 5 fps for 51 frames, then around 2.6fps
- RAW: around 5 fps for 21 frames, then around 0.9 fps
- RAW + JPEG: around 5 fps for 20 frames, then about 0.6 fps
- Recovery time: around 15-30 seconds
Autofocus speed / accuracy
The A580 uses the same new 15-point AF module that is employed in the Sony A-55. It is Sony's most advanced yet, and in day-to-day use with static subjects AF is very fast and very accurate. In the hundreds of sample shots we took of static subjects we could never find a main subject out of focus, no matter what light situation we were shooting in.
When shooting fast moving subjects the AF system cannot always keep up with the action but for a camera in this class that is not unusual. In demanding shooting situations such as sports or action photography, where efficient predictive AF is called for, are one of your main photographic applications you are arguably better off investing a little more money in a semi-professional DSLR such as the Nikon D300S or Canon EOS 7D.
While the Sony A580 is one of the very few DSLRs that can focus equally fast in live view mode as in 'normal' mode (when framing with the optical viewfinder) things slow down considerably when using the contrast detect AF system in Focus Check live view. The system only works with SAM (Smooth AF motor) lenses but even then is only really suitable for static subjects. That said, the competitors' contrast detect is not faster and on the A580 you have at least the option to shoot in live view, using the faster phase detection AF.