New Canon, Nikon and Sony DSLRs gain autofocus for video

ByJefferson Graham, USA TODAY
June 13, 2012, 6:48 PM

— -- Until recently, digital SLRs have been notoriously tough to focus during shooting — despite their reputation for great video.

Yet the cameras are beloved by photographers-turned-video-enthusiasts, because the imaging chip in them is some 20 times larger than that found in a traditional video camera. DSLR video looks sharper, more colorful and cinematic than footage shot on a camcorder. And the cameras themselves are more compact, easier to tote and way less expensive than camcorders with comparable features.

However, once you started shooting a scene, there was no way to adjust the focus — until now. A new crop of DSLRs from Sony and Nikon offer greatly improved auto-focusing. That's good news this Father's Day for shoppers thinking of getting Dad a camera. Or you could give Dad a rain check for the eagerly anticipated Canon Rebel T4i, which will be in stores come Tuesday.

A closer look:

Canon Rebel T4i. The newest and most innovative, Canon's just announced update to its Rebel lineup is both pricey ($849 for body only) and hard to get. Amazon and other e-tailers report limited supply.

The original Canon Rebel helped popularize DSLRs when the first model was released in 2003. It's been the best-selling DSLR since, according to technology research firm IDC. Later models since the T1i2 have featured video, first with 720 high-definition, and then full 1080p HD with 2010's T2i.

To focus those, you put your finger halfway down on the shutter to set it, then start recording by pressing the red record button on the back of the camera. But the recording could go out of focus if you moved your camera, your subject changed position, or another person entered the frame.

With the new Rebel, you no longer have to keep your finger on the focus button. Just move the camera while looking at the subject on the LCD preview window. The camera uses a combination of "face detection" and "scene detection" to determine focus.

In our brief tests at Canon's facility in Los Angeles, the T4i kept its focus even as we moved the camera around the room, from person to person. Canon says it made this breakthrough by creating a new image sensor for the Rebel that emphasizes video.

Another innovation: silent focus. On both the Sony and Nikon models referred to below, the camera microphone picks up the sounds of the lens motors focusing. With two new accessory lenses for the T4i, that doesn't happen. The Canon Stepping Motor (STM) lenses available are an 18-135mm wide to telephoto zoom, and a fixed-focus 40mm portrait lens.

Both the new and ultra-pricey $3,499 Canon 5D Mark III and the T4i can shoot video clips up to 29 minutes long. This means you could use the T4i to document a school play, recital, concert and the like. Just get a nice big memory card and hit record again after the first clip limit is reached.

Sony. Its newest DSLRs — the A57 ($799 with lens) and A37 ($699 with lens) — provide consistent auto-focusing once recording starts.

Sony came up with a new way to deliver light to the cameras' image sensors, bypassing the traditional focus mirror, which presents real-time images through the viewfinder. Instead, Sony has a translucent mirror that sends light to the image and auto focus sensor at the same time, using an electronic video viewfinder to simulate real-time viewing. By doing so, the photographer is able to keep a constant focus for video and take photos more rapidly. Sony's cameras let you record up to 29 minutes.

Nikon. The recently released D3200 ($699 with lens) beats the Rebel T4i and Sony A37 on imaging specifications. It has a 24.2 megapixel sensor vs. 18 and 16 for the Rebel and Sony. In reality, either are fine for most folks, but if you do a lot of cropping, you'll appreciate the extra megapixels of the D3200.

The Nikon promises "full-time" autofocus in its ads, via Face and Contrast Detection. "This has really been a hot topic, especially for DSLR users," says Lindsay Silverman, a senior product manager with Nikon. "It's a problem we needed to address. People said, 'We love your cameras, but when I go to video mode, the camera seems slow to focus.' " With the new camera, "they're much happier."

Other Nikon DSLRs offer video, but Nikon tells us the D3200 is the best example of its "full-time" auto focus features. It can record video clips up to 20 minutes in length. It also is more affordable than the T4i, with a lower price tag, and is readily available in shops and online. If you need to hand Dad that gift this weekend, it may be your easiest find.

Don't forget the accessories

If you want to get Dad started with DSLR video, here are a few accessories that can make for successful shooting.

•Buy a tripod. It's rare that you watch a movie or TV show and see handheld shots. Pros mount their cameras to steady the image because hands shake. It's impossible to hold them steady, especially when capturing a moving image. Tripods are on sale at Best Buy for as low as $25. This is the best investment you can make.

•Invest in a good, big memory card. Expect to spend $30 to $50 on the card. Video eats up a lot of memory, and you'll need a fast-writing card to handle it. Get at least a Class 10 memory card to handle the data and a decent-size card, from 16 gigabytes of storage on up. A 16 GB card will get you about 30 minutes' worth of footage; a 32 GB card will hold about an hour.

•Spring for an external microphone. The on-board mikes on cameras are cheap and often bad. The newer DSLRs all have mike inputs. Look to spend about $150.

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