Reasons to choose EOS-1D Mark IV
Released in 2009, EOS-1D Mark IV has about 519 mm² of sensor area, 16.1 MP effective resolution, and a 1,230 g body. Use these values to narrow the field, not as an overall image-quality score.


The D3 has the larger sensor area. More area usually means greater light-gathering potential, though real image quality still depends on sensor architecture and generation.
These cameras were released 2 years apart. Consider sensor generation when comparing pixel metrics.
Amber marks the value that is generally preferable in this comparison context. It is not an overall camera score.
The D3 has the larger sensor area. The EOS-1D Mark IV has the lighter body. The EOS-1D Mark IV has the higher effective resolution. The EOS-1D Mark IV is the newer release. Also consider the lens system and subjects you shoot.
Released in 2009, EOS-1D Mark IV has about 519 mm² of sensor area, 16.1 MP effective resolution, and a 1,230 g body. Use these values to narrow the field, not as an overall image-quality score.
Released in 2007, D3 has about 860 mm² of sensor area, 12.1 MP effective resolution, and a 1,240 g body. Use these values to narrow the field, not as an overall image-quality score.