Live View displays and operation

The A550 becomes the first DSLR since Olympus's innovative, if esoteric, Evolt E-330 to offer two distinct live view modes. The first use a tiny secondary sensor to give a low-resolution preview, allowing the use of the conventional DSLR phase-detection AF sensor to give rapid autofocusing (phase detection requires the main mirror to be down, so can't be used by other live view DSLRs unless the mirror is flipped down and up again before each shot). Alternatively, the mirror can be flipped up and the main sensor used to give a high resolution preview (this is the solution that all other manufacturers have settled on).

No overlay	Some settings, with exposure scale
With full shooting settings	Live histogram

MF Check Live View

This is the live view method used in all other current DSLRs - using the main sensor to give a high-resolution preview. Unlike other makers, Sony does not attempt to offer AF in this mode (no bad thing, since the only interchangeable lens cameras to do this at all well so far have been the Micro Four Thirds designs for which the whole system has been designed around contrast-detection AF). Instead, as Sony's name for it implies, this mode is used for the fine scale confirmation of manual focus.

No overlay	Some settings (no exposure scale)
With full shooting settings	Magnified MF Check live view

Smart teleconverter frustrations

We weren't convinced by the usefulness of the smart teleconverter button on the A350 but were deeply entertained by the frequency with which it would prompt the response 'Invalid Operation.' This has been partially rectified with the A550 - not by automatically switching you into a mode in which you can use the feature, but by giving longer descriptions of why it's not currently accessible. Again, it can only be used while shooting JPEGs in secondary-sensor live view mode which, delightfully, means that if you have the misfortune to start off in main sensor (MF Check) live view mode, you can potentially hit three different error messages before you get to the function you're trying to use.

The only reason I'm devoting so much space to what might seem trivial quirk is because of the jarring effect of being given warning messages. Nothing separates you from the shooting experience quite like the camera locking-up and telling you that it can't do what you're asking of it.

	If you are shooting raw files using the optical viewfinder (which doesn't seem an unreasonable thing to do as a keen DSLR user), and you try using the MF Check live view then you find yourself at the eye of the perfect storm - three error messages away from being able to use the Smart Teleconverter. The first press of the teleconverter button will tell you that you have to exit MF Check live view
	But, having done this, pressing the Teleconverter button again won't yet yield that zoom-by-cropping effect you're after. No, this time it'll tell you that you have to be in live view mode.
	Finally, you'll be reminded that you can't use the digital teleconverter while shooting RAW images. And, while it's unlikely that you'll ever go through this whole sequence, it does show that just how easy it is to accidentally lock the camera up, while it tries to educate you about the futility of trying to use the Smart Teleconverter.

Overall handling comments

The A550 is a big improvement over the A380 - with a greater degree of direct control, a much more hand-shaped hand grip and better button layout meaning it can be used comfortably in a manner that is similar to other DSLRs. Essentially it's a lot like the A350 (which it appears to be an evolution of) and allows easy manual selection of the AF point.

The viewfinder has also been improved over the other Sony live view DSLRs, though the A550 is still generally more pleasant to use in its main (secondary-sensor) live view mode than as a conventional DSLR. The new exposure display is a really nice idea but one that's been poorly implemented - it doesn't help to give a clearer understanding of aperture/shutter speed pairs or of the role of exposure compensation - and is more likely to confuse than educate the first-time DLSR user.

Another improvement over the A350 is the decision to devote the two most easily-reached buttons to exposure compensation and AEL, rather than the less useful Smart Teleconverter option. It still feels like a user interface with a fair number of quirks (which was always likely to be the case on a camera with three distinct mode or operation: Live view/OVF/MF Check Live View). Although every effort has been made to make behavior consistent across all three modes, the inevitable inconsistencies - the Smart Teleconverter button is used to magnify the main live view mode but it's the AEL button if you're in MF Check live view.