Pentax just added a second lens to its digital medium-format lineup which already accepts most 645 lenses from the film days. This one is designed to be optimal for ultra-high resolution sensors like the one used on the Pentax 645D.
The Pentax D FA645 25mm F/4 is an ultra-wide angle lens, equivalent to 19mm in 35mm terms, designed to resolve extremely fine details. Just like the 645D, this one is fully weather-sealed, providing protection against the elements.
This new lens has a highly curved front element and so the built-in hood is there to provide much needed protection against physical damage. Given that such lenses cannot accept normal filters, Pentax has designed this one with a slot to accept rear 40.5mm filters. A truly smart implementation even lets the included circular polarizer to be rotated using a control on the lens barrel.
The Pentax D FA645 25mm F/4 will be available from April 2011 for a suggested price of $4999.