The Pentax Q uses a 1/2.3-inch CMOS image sensor to create the smallest interchangeable lens camera on the market.

This system, which was launched in June, bridges the gap between compact cameras and full-on DSLRs with its 12.4 effective megapixels, varying image sizes (4:3. 3:2, 16:9 and 1:1), RAW (DNG) file saving, HD movie recording (up to 25 minutes consecutively), bokeh control, shake reduction, four exposure modes and five Q mount lens options.

It also offers a metered manual, aperture priority alongside a slew of programmed modes, such as Sunset, Blue Sky and Food and continuous shooting (up to five frames per second). The sensor, which is made by Sony and has not yet been used in any other camera, causes a slightly deeper depth of field than usual, but the Blur Control (BC) setting allows the user to throw the background out of focus.

The Q lenses have been developed exclusively for the Pentax Q camera and include a unifocal prime (47mm), a zoom (27.5-83mm), a unifocal ultra-wide-angle fish-eye (17.5mm), and two "toy" lenses, a unifocal wide-angle (35mm) and a unifocal telephoto (100mm). Focal lengths are described here in 35mm format.

Described by the company as "pocket sized, go anywhere", the Pentax Q lived up to its reputation during my short test in London's Soho. Street photography can prove challenging with a bigger camera, but the Pentax Q was unobtrusive and discreet. I also enjoyed switching between image sizes and liked the freedom to experiment with different cropping options in-camera. It was good to see the camera records a standard 4:3 version as well as the cropped alternatives too, giving you flexibility after the event if you need it.

Sample of the Pentax Q's 1:1 image size option. © Katie Poole

It wasn't love for me, though, as I found the camera's diminutive size almost too small and slightly awkward. I also struggled to see the images on the LCD screen in the bright afternoon sunlight. BJP will report back with a longer test soon.

The Pentax Q is available in a kit with the prime lens for £599, or in a kit with the prime plus the zoom lens for £729. The fish eye and "toy" lenses are sold separately, the RRP standing at £149 for the fish eye and £129 for the other two. The camera will be on sale by mid-September in Jessops and other good camera shops.