Both Blackmagic 6K G2 and Nikon D5 have 21.0 MP resolution sensors but Blackmagic 6K G2's sensor is Super 35 (23.1 x 13 mm ) and Nikon D5's sensor is Full frame (35.8 x 23.9 mm ).
Since Nikon D5's has a larger sensor area with the same resolution, this means that it also has a larger pixel area hence better light collecting capacity for a given aperture compared to Blackmagic 6K G2.
Below you can see the Cinema Camera 6K G2 and D5 sensor size comparison.
Sensor Size and Resolution Comparison image of Blackmagic 6K G2 and Nikon D5 Cameras
As seen above, Nikon D5 has a 2.9x Larger sensor area than Blackmagic 6K G2. Larger sensors give photographer more control on the depth of field and blurry background compared to smaller sensor when shot in same focal length and aperture.
Sensor size sets the circle of confusion, so it drives how much depth of field each
of these bodies gives you at a given aperture. You can calculate it exactly for the
Blackmagic 6K G2
or the
Nikon D5 ,
including hyperfocal distance.
One thing to watch when comparing these two: they have different sensor sizes
(Super 35 versus Full frame),
so compare them at the same framing rather than the same focal length.
Put the same focal length on the smaller sensor and it will show less depth of
field, not more, because it also crops tighter. The calculator shows the
full frame equivalent focal length for each body so you can match the framing.
