March 6, 2008: Most new DSLRs now have some kind of Live View feature that lets you compose your picture on the LCD screen. 

Sony’s newest DSLRs, the a300 and its big sibling, the a350, have some advanced technology that makes that process easier, faster and less cumbersome. According to Sony:

When you switch to live view operation, an innovative new pentamirror tilt mechanism directs the subject image to a dedicated live view sensor positioned over the viewfinder eyepiece. 

Since I don’t think the people at Sony do a particularly good job of explaining why that’s significant, let’s see what the always informative and entertaining David Pogue of the NY Times has to say about this. He begins by explaining the limitations of current Live View systems, then outdoes Sony in explaining why their system works so much better:

Actually, a few recent S.L.R. models do, in fact, have this Live View feature, but it’s mostly a disaster. It works by flipping that mirror up out of the way, so that light from the lens hits the image sensor, which feeds the image to the screen. Trouble is, once the mirror goes up, no light hits the autofocus sensor, so the camera can’t focus.

So here’s what happens when you press the shutter button. There’s a noisy clank as the mirror drops down again; the screen goes black; the camera computes focus and exposure; the mirror lifts again; the screen comes back to life; and finally — a second or so later — the shot is recorded.

In other words, Live View on existing cameras is slow, noisy and deeply confusing. All of this silliness arises because the camera’s image sensor must do double duty: it’s responsible for supplying the screen with a live preview and for recording the shot.

Sony’s technical breakthrough on the A300, therefore, was this: “Duh! Put in another sensor!”

On this camera, turning on Live View sends light from that main mirror onto a second sensor, one that’s devoted solely to feeding the preview screen.  (Snip)

As a result, Live View is a completely different experience. The camera focuses quickly as you aim the lens, without ever blacking out the screen. When you press the shutter, the screen doesn’t go on-off-on, there’s no loud clacking, and there’s no baffling exhibition of mirror calisthenics inside the camera.

I was just talking to Laurel, our Queen of All Contests at The Digital Photography Show about how, based on what I’ve heard about Live View, I’ve never even tried using it on my Canon 40D. But I have to say, I’d at least play with it if I had one of these new Alphas. I’ve always said that if any company was going to threaten Nikon and Canon in the DSLR market, it was going to be Sony.  Nothing against any of the other manufacturers, but Sony has the deep pockets, marketing presence, and relationships with the major retailers to be a big player if they want to be.

Uh, anyone remember HD DVD?

And before I hear from outraged Pentax, Olympus, Samsung, Panasonic, etc users, I’m not saying that Sony’s cameras are necessarily the best for all shooters.  Pogue’s review lists several shortcomings of the Alphas that would be showstoppers for many photographers, especially enthusiasts. But by making Live View more usable on a DSLR, Sony has overcome one of the major obstacles experienced by people stepping up from a point and shoot: Why can’t I use it like I used my old camera?

Now they can.

Scott

This entry was posted on Friday, March 7th, 2008 at 6:35 am and is filed under General. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.