There are a lot of action cams available, but few offer a feature set targeted at professional use and results the way Replay XD has done with its Prime X camera. And it all starts with its lens.
The f2.7 lens (T2.8 for the filmmakers out there) Hyperion CinePrime X has a 140-degree angle of view. It was exclusively designed for this camera using aspherical, antireflection-coated, all-glass elements including special low-dispersion elements used to reduce chromatic aberration. A replaceable impact-resistant glass lens cover protects the whole thing.
Behind the lens is a 1/2.3-inch 16-megapixel CMOS sensor, which the company says uses 33 percent less power and has higher sensitivity and better dynamic range than previous models. With it, the camera can record video at up to 1080p at 60fps and 720p at 120fps but also has cinema settings for 24 and 48fps.
Now, that's a lot of specs and details that may not mean much to you, especially if all you're interested in is if it's better than a GoPro. The answer to that really comes down to your needs, so it's not a simple yes or no answer. But what I can say is the Prime X is a standout for its features and design at its $300 price. Pricing in Australia is AU$395, and in the UK through Amazon and other dealers it's about £200, so you'll have to weigh your options at those prices.
Design and features
The tubular aluminum body measures 1.2 by 3.9 inches or 30 by 98mm and weighs only 3.5 ounces or 99.2g. By comparison, it's roughly the size of a roll of US quarters, but less than half the weight. That allows you to put this camera -- or two or three of them -- where others won't fit.
Minor impacts from falls or debris shouldn't pose a problem, and its removable lens cover means you don't have to worry about accidental scratches. Also, as long as the rear cap covering its Micro-HDMI, Mini-USB ports and microSDXC slot is screwed down tight, the camera is waterproof without an additional housing down to 10 feet (3m). A dive housing is available should you want to explore down to 197 feet (60m).
Short of using zip ties or duct tape, there's no way to mount the camera on its own, which is the biggest issue I have with the design. That, and the aluminum body acts as a heat sink, so it can get hot with extended use (though it didn't seem to have an impact on camera performance).
Instead, what Replay XD uses are plastic collars that wrap around the middle of the camera with two tabs on the bottom, which mount securely into the company's SnapTrays. Arrows on the collar's top can be lined up with etched markings on the camera so that, if the camera is mounted upside down, for example, you can rotate the Prime X into the correct position. Once locked into a SnapTray, the camera will not rotate, so you don't have to worry about your shot suddenly being crooked or upside down.
The Prime X comes with a nice assortment of accessories (one of the nicest I've seen in a while) that includes two adhesive SnapTrays -- one curved, one flat -- and an extra 3M adhesive pad. There's also a SnapTray with a tripod mount. To slide into the SnapTrays, you get a LowBoy mount for when you want the lowest profile possible and a locking tilt mount so you can angle the camera up or down.
Also in the box is a 4GB microSDHC card (cards up to 128GB are supported); a microfiber camera pouch; a Mini-USB cable; a set of stickers to place over the internal mic to reduce wind noise; a printed user guide; and a nylon case to store everything in.
Lastly, the internal 1,700mAh battery is capable of continuous recording for up to 3.5 hours on a single charge. A representative for Replay XD said this was achieved recording at 720p at 60fps, and that they had hit 2.5 to 3 hours on 1080p at 60fps.
In my tests, I averaged 1 hour and 45 minutes at 1080p60, but that was at its highest bit rate of 25Mbps, which is the best quality video you'll get from the Prime X. All in all, that's not a bad battery life, especially given how small the camera is. However, since the battery is built-in, you'll either need to recharge once the battery is drained or connect an external battery or power cable to keep recording.