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Sony improves focusing with most recent RX10 IV bridge camera

Create: 01/14/2018 - 18:02
Sony RX 10 IV


  • Sony claims autofocus speed of 0.03 seconds
  • Touch-enabled 3.0-inch LCD monitor
  • Intended buyer: Advanced amateur

Even as Sony continues its work on its E-mount mirrorless cameras, it continues to develop its RX10 bridge camera.

The latest version, the RX10 IV, continues to use a 1.0-inch 20.1-MP Exmor RS CMOS sensor with a sensitivity of ISO 100-12,800, which can be extended to 25,600.

The lens again is a full-frame equivalent 24-600mm Zeiss Vario-Sonnar superzoom. It’s a fast lens: f/2.8 at the wide end and f/4 at 600mm. It contains 18 elements in 13 groups and has six aspherical lenses. With a long end of 600mm, it’s a good thing that the lens is image stabilized via Sony’s Optical SteadyShot. The lens aaccepts 72mm filters.

The lens’ close-focus distance is 2.4 feet at the 600mm setting. There are separate lens rings for zoom, aperture and manual focus.


Where the RX10 IV shines, Sony claims, is with its autofocus speed of 0.03 seconds and up to 24 frames per second shooting.

Sony says improved focus speed was something that its users have requested. The autofocus system is described as “Fast Hybrid AF,” which combines 315 phase-detection AF points covering about 65% of the sensor and contrast-detection AF.

The use of phase- and contrast-detection autofocus has been showing up increasingly in mirrorless cameras, as well as some of the higher-end fixed-lens devices.

To further assist the camera, Sony has added “High-density Tracking AF,” which it uses in some of its higher-end interchangeable-lens cameras. This system employs autofocus points around a subject that helps the camera keep it in focus should it move across the scene. This can be useful in sports and wildlife photography.

The RX10 IV uses a single SD or Memory Stick Duo memory card for storing RAW and JPG still images and video. These days, you should plan to purchase a high-speed Class 10 card if you expect to record video and a UHS-3 card if you want to record 100 Mpbs video. The camera can record 4K video, as well as up to 100 frames per second in Full HD. There are microphone and headphone jacks.

Other ports include Micro-USB and a USB 2.0. The Micro-USB can also be used to connect several Sony accessories, such as a remote control unit. The The camera also has built-in WiFi, NFC and Bluetooth connectivity for transfer of images to a computer or smart device.


The RX10 IV has both manual and electronic shutters. The electronic shutter offers speeds up to 1/32,000 and uses what technology to reduce the “rolling shutter” effect that occurs when photographing fast-moving subjects. The electronic shutter also has the advantage of not emitting any sound when during image capture.

The camera can record up to 24 frames per second with autofocus and autoexposure for each shot. It can maintain this rate for up to 249 “Fine” JPGs.

The RX10 IV has a built-in pop-up flash, as well as the ability to use a compatible flash gun via the “multi-interface shoe” on the top of the viewfinder housing.

Like the previous models, it provides both an electronic viewfinder and a tilting 3.0-inch LCD monitor. This is a touch-enabled monitor, which is a first for Sony’s RX series of cameras. There is also a small monochrome LCD panel on the top of the camera, displaying basic information about the state of the camera.

A single lithium-ion battery is good for about 400 still photos when using the LCD and about 200 when shooting with the EVF.

The RX10 IV is dust- and moisture-resistant although not waterproof.

The camera is 5 1/4 x 3 3/4 x 5 1/8 inches (132.5 x 94.0 x 127.4mm) and weighs just under 2 1/2 pounds (1,050 grams).

The Sony RX 10 IV is available now for about US$1,700.

About the Author

Mike Elek is a longtime journalist and was one of the original editors for The Wall Street Journal Online. He also has worked as a reporter and editor in Pittsburgh; Philadelphia; Vineland, N.J.; Poughkeepsie, N.Y.; New York City; and Hong Kong. He is a U.S. Air Force veteran. He shoots with film and digital cameras.