Today I went for another photo walk with the Sigma 150-600mm Contemporary and the SD1 Merrill camera. In comparison to last time, the weather was sunny and nice this time, so I didn’t have to increase the sensitivity range to ISO400 in order to achieve a sufficiently short shutter speed. Despite the long focal length of 900mm (in full frame terms), even 1/250 s would be sufficiently short as the image stabilization does a good job. Unfortunately, birds move very quickly, so 1/500 s to 1/1000 s are still a must. You don’t even realize before taking their picture how quickly birds actually move their heads when they observe their surroundings in panic, watching out for a potential danger ahead. Only later you can see that their head is blurred. Unfortunately, image stabilization doesn’t help at all against motion blur.
You would think that such an extremely long focal length should be enough to take format-filling pictures of smaller birds as well. As I found out after three photo walks, this isn’t the case. You have to get very close to them. For me that’s the most difficult thing about bird photography.