The new lens - the SMC Pentax-D FA645 25mm f/4 AL[IF] SDM AW - will be the second specifically developed for the Pentax 645D medium format camera. When released late last year, the camera, which had been first announced back in 2005, came with a 55mm lens. However, the system is compatible with all film lenses previously released by Pentax.

Now, the 25mm lens - equivalent to 19.5mm in 35mm format - will add another option to 645D users. The lens sports a susper-sonic dynamic motor, is dust-proof and weather resistant, and is composed of 12 elements in eight groups. It features an aero-bright coating to reduce flares.

The lens has an aperture range of f/32 to f/4, an angle of view of 95°, a maximum magnification of 0.11x and a minimum focusing distance of 40cm.

The 25mm lens weighs 1070g and comes with a case, lens cap and two filters - Normal and C-PL.

It will retail at £3780.