The aging Pentax 645Z made its appearance at DxOMark, slipping into the second place between the Hasselblad X1D-50c and the Nikon D850 with a score of 101. Its been a great year for digital camera image quality improvements yet the 645Z is already 3 years old! Although DxO Mark did not rank it until now, Pentax 645Z users surely new of its immense image-quality!
The Pentax 645Z is the only Medium Format DSLR on the market. Its 50 megapixels CMOS sensor is 44x33mm, just like sensors the the Fujifilm GFX-50S reviewed here and Hasselblad X1D-50c. This one though has a reflex optical viewfinder and a legacy Pentax 645 mount that was hugely popular in the film days of Medium Format. This type of camera is designed for maximum image-quality thanks to a large sensor without an anti-alias filter. Pixels are correspondingly which also maximizes dynamic-range and sensitivity to light. The 645Z has an ISO 100-204800 sensitivity range.
The DxOMark Score of 101 places right above the best performing DSLR which is what someone getting into Medium Format would expect. The scores breaks down into 26 bits of color-depth, 14.7 EV of dynamic-range and 4504 ISO score. There is probably slightly more read-noise in a sensor of the 645Z’s age which explains why both color-depth and dynamic-range fall behind the Nikon D850 and Hasselblad X1D-50c. Where the 645Z recovers and actually takes the crown is its best-ever 4505 ISO score.