Blue Grosbeak at Lake Hodges

I found a loudly singing Blue Grosbeak perched out on the top of a laurel sumac at Lake Hodges recently. He gave me a chance to adjust my aperture and see how the Auto-ISO responded. I gradually made my way a bit closer, starting at about 50 feet away and working to perhaps 35 feet. But the size difference in the following shots is due to how tightly I cropped each exposure, not how close I was.

Canon EOS 7D Mark II, Canon EF 100-400mm f/4.5-5.6 IS USM. 1/2000s f/10 @ 400mm ISO 1250

The bird was close enough to me, and the hill across the lake far enough away that f/10 didn't really make the hillside more in focus as I thought it might. And ISO 1250 is not grainy on this camera, so photo quality was not affected by high ISO.

Blue Grosbeak. Lake Hodges, California. July 4, 2018.
1/2000s f/7.1 @ 400mm ISO 640

The difference between the first two photos is one full stop. f/7.1 to f/8 is 1/3 stop. f/8 to /9 is another 1/3 stop. f/9 to f/10 is a final 1/3 stop. A full stop is twice as bright (or 1/2). And the ISO dropping from 1250 to 640 is a corresponding full stop.

Smaller in frame crop:

1/2000s f/7.1 @ 400mm ISO 640

Then I moved sideways and dropped down a bit to put blue sky behind the bird. I increased the exposure compensation one full stop because the bird was fairly dark against bright background. In order not to increase the ISO, I opened the aperture wide to f/5.6 (+2/3 of a stop brighter than f/7.1). Thus, Auto-ISO chose 500.

1/2000s f/5.6 @ 400mm + 1 stop EC ISO 500

I was disappointed at the number of shots that were out-of-focus, however. The shutter speed was more than fast enough for hand-holding, especially with image stabilization. Perhaps there was some heat shimmer in the air? It was only 8:40 am, though. More experimentation is in order.

Good photos were obtained full open (f/5.6), which is a happy discovery. This same lens on my old camera produced many more in-focus shots stepped down to f/7.1.