Hi Pablo, all was shot from very firm Manfrotto 536 tripod and 808 head with OS turned off using cable release. Concerning details, there are actually plenty like wall and window frame paint cracks. Main 150-500 advantage over 50-500 is almost constant resolution and contrast over broad f-stop range. However, at f/8 to f/10 Sigma 50-500 excels in all respects.
Thanks for doing these tests. To me it looks like the 150-500mm clearly wins at 150mm, but the shots from the 50-500 seem much, much sharper above 300mm (hard to tell at 400mm and 500mm because your subject doesn't have much resolution).
