Sony SLT-A99: Full-Frame Translucent Mirror Camera and Dual AF (preview)

Sony SLT-A99 photo camera
Written by Erik Vlietinck

Sony announces a new full-frame DSLR — popping a full-frame sensor in an 800 grams light magnesium alloy TMT Technology body.

Sony, after two years of planning, finally has unveiled its full frame DSLR. It’s a re-invention of sorts. With its SLT-A99, Sony has popped a full-frame sensor in an 800 gram light magnesium alloy translucent mirror technology camera body. And the SLT-A99 is the first full-frame camera with a Dual Auto-Focus (AF) System. Here’s a preview.

This system has 19 sensors and a 102 AF point system, as well as a new AF range control function to set the distance range recognized by the AF system.  It works similarly to a golfer’s range finder.

Sensitivity ranges from ISO 50 to 25600. The Alpha 900, its predecessor, had nice low noise levels. The SLT-A99 betters that with a new area-specific noise reduction (NR) algorithm that I can’t wait to test.

Sony SLT-A99 photo camera

Sony makes consumer, broadcast and cinematographic video camcorders. The $97,000 Sony F65 was named best cinema camera at Zacuto’s camera shootout recently, lining up just before runner-up ARRI Alexa.

The SLT-A99 offers video recording with nice specs. That includes: HD/60p — switchable to 50p/24p —  with non-stop Continuous AF. What’s more, the only other photo camera maker which is in the camcorder business too, cripples the HDMI-out of its EOS 5D and 7D models. Theirs will include the LCD info.

I asked Sony’s rep if the HDMI-out on the SLT-A99 is clean and the answer is that it’s as clean as a whistle. Which means that you can hook up a Ninja2 or any other field recorder to the SLT-A99 and record straight to ProRes or whatever other codec you happen to like.

Sony SLT-A99 with Zeiss lens

With Canon (not Nikon, but they don’t make camcorders) you’re stuck with AVCHD 2.0, which is the internal recording format of the Sony too.

Other brands’ audio capabilities are puny at best. A minijack is all you get. Sony will be selling a professional XLR adapter kit for the SLT-A99, so you can plug in a Rode NTG-3 or use the kit’s included shotgun micro. With it, you’ll be unique. No other dSLR vendor offers such an option.

The full-time Continuous AF Movie feature, which was introduced on the SLT-A77, should allow smooth, non-stop tracking of moving subjects. Other movie-oriented enhancements include uninterrupted “dual-card” recording using both of the camera’s media slots.

Video shooting with a full-frame sensor is detrimental to battery life. The camera could fall short in this area, but Sony says stamina can be tripled by installing the new VG-C99AM Vertical Grip that gives the camera up to three batteries in all. It’s even possible to exchange batteries on the fly without interrupting movie recording.

At the heart of the SLT-A99 is a newly developed full-frame Exmor CMOS sensor with 24.3 effective megapixels. That teams it up with Sony’s BIONZ image processing engine. The sensor’s resolving power is enhanced by a newly developed separate multi-segment optical low-pass filter.

Another Sony-only feature is the auto-focus system. A 19-point AF system with 11 cross sensors is complemented by a multi-point focal plane phase-detection AF sensor. With 102 AF points, this additional AF sensor overlays the main image sensor. Combined with Sony’s Translucent Mirror Technology (TMT), the Dual AF System should give you ultra-fast, accurate autofocusing that maintains tracking focus even if the subject leaves the 19-point AF frame.

A new AF range control function allows you to set the distance range recognised by the AF system. This helps you focus on distant action when shooting through a nearby wire fence, for example.

Because there’s no real mirror, the viewfinder is an XGA OLED screen. The one on the SLT-A99 offers 100% frame coverage, even if you’re shooting with a lens that’s optimized for cameras with an APS-C sensor. The angle of view is converted automatically for image recording and display.

Tilt-able LCD screen on the SLT-A99

There’s also a three-way tiltable 1229k-dot (VGA equivalent) XtraFine LCD with Sony’s new WhiteMagic technology that is said to boost screen brightness in outdoor conditions.

For, I’m Erik Vlietinck.