The Datacolor Spyder4 Express monitor calibration tool marries straightforward operation with extensive display compatibility.

It can be used with standard LCD, LED and wide-gamut displays, and OLED panels and iPhones and iPads.

The Spyder4 incorporates a seven-colour sensor, which promises more accuracy over the Spyder3, while double-shielding over the colour filters is said to stop colours changing over time.

Calibrated images must be viewed through the SpyderGallery app. This works with your iOS device's own photo library, in addition to sites such as Facebook and Flickr.

On an iPad the colorimeter sits happily to the side of the screen, although it's more awkward with an iPhone given the size of the device. Still, once the app is downloaded from the App Store calibration only takes 90 seconds, with the colorimeter plugged into a MacBook or iMac and working over a Wi-Fi connection.

Calibrating a MacBook Pro takes a few minutes, with before and after samples available post-calibration.

The device appears to return the display to a point of faithful reproduction, and subsequent calibrations return consistent results, although the absence of an ambient light sensor means that ambient light levels are not taken into account.

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