When it made up the term "S.L.R.," the technology terminology industry was not operating at its peak creative powers.
An S.L.R. is one of those big, black, professional-style cameras. They do things that make pocket cameras look like pretenders: they can blur the background, take lower-light shots without a flash and shoot with no shutter lag (the delay after you press the shutter button). And thanks to enormous light sensors and lenses, the photos just look fantastic.
But ouch -- that name. Even if you know what S.L.R. stands for ("single-lens reflex"), you have no idea what it means. "Single lens" is misleading, because the whole point of these cameras is that you can attach dozens of different lenses. And to most people, "reflex" refers only to wincing when they see the price.
Kidding aside, historically, there was a point to the term "single-lens reflex" (yes, I use Wikipedia, too). It describes the mirrors and prisms inside that bend the light from the lens to your eye.
Recently, a new generation of mirrorless cameras have hit the market. They look and work like S.L.R.'s -- interchangeable lenses, no shutter lag and so on -- but they're smaller and they capture high-definition video. (Since they're not technically S.L.R.'s anymore, Popular Photography magazine proposes the term I.L.C. for them, for "interchangeable-lens compacts." Let's run with it.)
Sony's new Alpha A55 camera, available in October ($850 with 3X zoom lens), is an S.L.R. -- sorry, an I.L.C. -- that changes a bunch of games at once. It accepts any of Sony's existing 33 Alpha lenses, but its radically different guts give it talents no other camera has had before.
This will require a paragraph or two of technical slogging, but you'll feel rosy and smart when it's over.
In a typical S.L.R., light from the lens hits a mirror, which bounces light up to your eye and onto a focusing sensor. The blessing: you see what the lens sees. The curse: when you take the actual photo, the mirror has to flip out of the way so that the light falls on the main image sensor (the "film"). For that fraction of a second, the camera can't focus. If someone or something is hurtling toward you, a typical S.L.R. may have trouble keeping rapid-fire shots in focus.
That's also why most S.L.R.'s can't change focus when you're shooting video. If you start filming on something close up, and then pan to something across the room, the video goes out of focus.
Still with me?
All right. Sony's A55 camera adopts a new spin on a decades-old photographic idea: the mirror is translucent. It splits light between the focusing sensor and the image sensor -- all the time. The mirror never has to flip up to take a picture, so the autofocus never goes blind when you take a shot.
As a result, the camera can shoot an incredible 10 shots a second, refocusing all the way. Sony says no other camera in the world can do that.
The camera also shoots beautiful, high-definition video -- and it can change focus as you pan the camera, gorgeously and cinematically.
Very few S.L.R.'s, or even I.L.C.'s, can do that trick, refocusing while filming.
But the Sony doesn't just change focus in video. It changes focus fast. According to Sony, the A55 is the first camera -- or camcorder, for that matter -- to use what's called phase-detection focusing for video. (Other cameras, and all camcorders, use a slower system called contrast detection.) That's only possible because, in this camera, the autofocus sensor can see the scene all the time.
Now, to pull off this unusual design, something had to go, and it was the optical viewfinder. When you hold this camera to your eye, you're basically looking at a tiny TV screen in the eyepiece, rather then peering out through the glass of the lens. In other words, it's an electronic viewfinder.
Photographers usually pooh-pooh electronic viewfinders, because no screen is as sharp as real life. But Sony's viewfinder is extremely big, bright and sharp (how does 1.4 million pixels strike you?). And having a screen in the eyepiece gives you all kinds of advantages you don't get when you're just looking through glass.
For example, you can see exactly what effect your settings will have before you take the shot (white balance, exposure, focus, and so on). You can summon digital overlays in the viewfinder, including a horizon level. You can magnify the scene up to 15 times for precise manual focusing. You can play back your photos right in the viewfinder -- a rare, surprisingly handy feature, especially when you're experimenting with settings or reviewing your photos in bright sunlight (which washes out the screen somewhat).
You can shoot video with the camera to your face, too, a more stable way of holding the camera. (Most S.L.R.'s require you to look at the screen on the back to shoot video.)
The best part is that these gee-whiz features are part of a generally terrific camera. It has Sony's Sweep Panorama mode, where you swing your arm in an arc as the camera snaps away -- and then, two seconds later, the camera displays an automatically assembled, stunning 260-degree panoramic photo. The quality is fantastic, although it's auto-mode only.
The A55 also creates high-dynamic range photos automatically -- a neat trick by which it restores detail from areas that are too bright or too dark by superimposing three photos with different exposures.
There's a built-in stereo microphone for use with your video, plus a mike jack. The button placement is excellent -- especially the dedicated Video Record button (no switching modes when filmic inspiration strikes). The tilting, rotating, flip-out screen lets you shoot over your head, at knee level or even self-portraits. You can also fold the screen flush against the camera (with either screen in, for protection, or screen out).
I was so confident in the A55's ability not to muff photo ops that I did a risky thing: I used it as the sole recording device for my son's one and only sixth birthday party. Happy ending -- the ratio of winner shots to losers was amazingly high. Even the low-light candle-blowing moment looks fantastic in video, like a Scorsese shot it. (Have a look at the sample photos that accompany this column.
Now, there are a few flies in the ointment. That 10-frames-a-second mode requires a lot of light; indoors, these superburst-mode photos are sometimes too dim, and you can't adjust the aperture in this mode.
The camera is small and light compared with true S.L.R.'s, but it's still much bulkier than, for example, Sony's own minuscule NEX-5 (the smallest of this type in the world, although you give up a lot of features -- like a flash, a mode dial and a wide choice of lenses).
There are two separate playback modes, one each for stills and videos, and it's annoying to have to switch between them. Battery life is about 350 shots a charge, which could be better. And some of the fancy modes (like high dynamic range) require a lot of processing after each shot, during which time you can't use the camera.
Still, this camera takes pictures and videos as well as anything in its price range -- and, in some cases, better than far more expensive equipment. (A sibling camera, the A33, is available now for $100 less. It gives you 7 frames a second instead of 10, and 14 megapixels instead of 16; it also does away with the GPS chip that tags each photo with your location.)
Even more exciting, it's thrilling to see Sony finding its mojo again, introducing radical new design ideas that, in this case, really advance the state of the art.
In other words, maybe the right term for this camera is neither S.L.R. nor I.L.C. Maybe it's really an E.S.F. (exciting step forward).