I take the same shot using the same lens on both camera I have with me in the field. The setting it's not exactly the same, but just to show up the difference. The old 1Ds are not bad. On tripod with 24-105L-
1- 1D4 -1/5s-100ISO- f14- at 32mm
2- 1Ds -0.4s-100ISO-f22- at 35mm

