Sensor and autofocus
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Sensor and autofocus

The 645Z uses the same 51MP medium format Sony CMOS sensor as the Hasselblad and Phase One cameras mentioned on the previous slide. This monster has dimensions of 43.8 x 32.8mm and a pixel pitch of 5.3 microns. To keep dust off of the sensor, the 645 uses Pentax's Dust Reduction II ultrasonic cleaning system.

Keeping with its predecessors, the 'Z' uses the 645AF2 mount, which is backward-compatible with 645AF and 645A lenses, too. With an optional adapter, classic Pentax 67 lenses can be used as well. The crop factor this medium format camera is 0.79x, so a 55mm prime acts as an archetypal 'normal' lens - equivalent to 43mm in 35mm terms. Pentax currently has sixteen FA 645 lenses available.

As you'll see, the 645Z has inherited quite a bit from the K-3 DSLR - making it one of the easiest medium format cameras to simply pick up and use. One of the most significant is the SAFOX 11 autofocus system, which has 27 points (25 of which are cross-type). Compare that to 11-points on the 645D, and even fewer on the Hasselblad and Phase One cameras. The result is really impressive autofocus, in both good and low light.

Given that it's a medium format camera, you know that the 645Z is going to have a large mirror. As could also conclude that the noise from this mirror would be pretty loud. And while you'll certainly notice, we were surprised to see that the 645Z's shutter is actually quieter than the one on the Sony A7r. In terms of durability, the shutter is rated for 100k cycles.