Digital Cameras Guide
The NEX-7 has a startup time of about 0.7 of a second, and the first shot can be taken in as fast as 1.5 seconds after flicking the power switch. One headline spec of the NEX-7 is its 0.02s (or 20ms) shutter release time lag - down from a typical 0.1s. This is achieved by using an electronic front curtain shutter. Incidentally, the new crop of SLT and NEX cameras are the first cameras from Sony to receive this treatment. The speed advantage comes about since it’s faster to switch pixels on and off electronically. By default, this setting is turned on, and in our test, it worked like a champ. Like the A77, the shutter fired instantly every time we pressed the shutter release button. And because shutter lag (broadly defined as the time between you depress the shutter and the time the photo is actually taken) is also affected by AF and metering speeds, Sony has implemented an accelerated image sensor readout and upped the processing power to speed up AF and improve overall camera responsiveness. There are a couple of instances when you’d want to revert to the mechanical front curtain shutter though: when you see a blurred image when shooting at high shutter speeds with an wide aperture lens, and when using an old Minolta/Konica Minolta lens.
The above being said, the NEX-7’s AF speed is a hair slower than the Olympus Pen E-P3 and the new Nikon 1 cameras. This was most noticeable under low light, when the NEX-7 hunted for just a tad longer. Still, it was very fast for an APS-C camera using contrast-detection AF. Shot-to-shot timing (even with auto review on) was an impressive 0.6 of a second on average.
The NEX-7 has a Speed Priority continuous shooting mode that bursts at a rate of 10fps, but has the AF and AE locked at the first frame. For predictable moving subjects, this is a great option to have; for subjects with erratic maneuvers, not so much. There’s a 3fps mode that refocuses/re-meters between shots.
LA-EA2 Lens Adapter
But there’s a way to get the faster AF onto the NEX-7, and that’s through the use of the LA-EA2 lens adapter. With it, you can use any A-mount lens on any E-mount body. Unlike the previous adapter (LA-EA1), the LA-EA2 has Sony’s translucent mirror technology baked into it to give you continuous phase-detection AF, and it’s applicable in both photo and video shooting. The built-in AF module sports 15 AF points, three of which are cross-type sensors. If you already have an arsenal of A-mount lenses and shoot a lot of action sequences, the LA-EA2 is a great accessory to have. At $459, it’s a hard sell for users new to the Alpha system.