The ‘Infinity Platform’ incorporates the core of Phase One's Capture One image processing into the IQ4 backs themselves. The ‘Capture One Inside’ arrangement delivers enhanced RAW file workflow management with editing and processing functions now controlled within the capture back. Importantly, the Infinity Platform provides more scope for upgrading and adaption in the future to help address the issue of maintaining the future value of substantial initial investments in the hardware. Phase One says this will also allow it to “… grow the IQ4, adapting and expanding incrementally to match the pace of technology”.

Photo: Phase One

The new IQ4 capture backs are optimised for operation on Phase One’s XF camera body, and there are three models – IQ4 150, IQ4 150 Achromatic and IQ4 100 Trichromatic.

The 150 megapixels models employ a new backside-illuminated (BSI) CMOS with an imaging area of 53.4x40 mm which, interestingly, Phase One is calling “full frame medium format” as a differentiation from “mirrorless medium format” and notes that they’re 1.5x bigger than the “crop sensor”. They also represent a 22 percent increase in resolution over the 100 MP models.

The total pixel count is 151 million, giving a maximum image size of 14,202x10,652 pixels which, at 300 dpi, represents an output size of 120.26x90.19 centimetres. The sensitivity range for the colour version is equivalent to ISO 50 to 25,600 while the B&W-only Achromatic model’s spans ISO 200 to 102,400. Phase One’s Achromatic sensors don’t have a Bayer colour filter grid and, consequently, deliver increased sensitivity, but they also lack an IR cut-off filter, enabling infrared B&W photography as well.

As with the IQ3 models, RAW files can be captured with either 14-bit or 16-bit image data. The pixel size is 3.76x3.76 microns, and the dynamic range is quoted at 15 stops. With 14-bit RAW capture, the maximum continuous shooting speed is 1.4 fps.

Photo: Phase One

The new IQ4 backs feature dual memory card slots for the XQD and SD formats, and the former will be upgradable to give compatibility with CFexpress devices. File management options include simultaneous recording for back-up purposes or a designated format assigned to a particular card slot.

The IQ4 backs have USB-C and Ethernet ports along with built-in WiFi, giving a choice of tethering (and powering) options. There’s also a new HDMI terminal. As before, there’s an 8.1 cm TFT LCD touchscreen monitor, a sensor-based electronic shutter, and the ‘XF Powershare’ functionality which allows for the hot swapping of either the camera battery or the back’s battery (which are conveniently the same type).

‘Capture One Inside’ delivers, among other things, improved preview quality, in-camera JPEG processing, ‘IIQ Styles’ implementation and various new tools (including time-lapse and bracketing which means these can now be applied independently of the XF camera body). The IQ4 Trichromatic uses the same 101 megapixels sensor as the IQ3 Trichromatic (which it replaces) with an optimised colour filter array, but with all the feature and function updates of the new generation backs. The IQ3 100 and IQ3 Achromatic models will remain available.

Australian pricing has not been announced so, as a guide, the Phase One’s published pricing in US dollars are US$51,990 for the XF IQ4 150, US$47,990 for the XF IQ4 Trichromatic and US$54,990 for the XF IQ4 150 Achromatic. These include a Schneider ‘Blue Ring’ prime lens of the purchaser’s choice. For more information visit