The focus isn't perfect. The range is quite shallow with the fieldscope, and I'm wondering whether it's better to set the focus a bit on the far side or a bit on the near side? I plan to test this on my next outing; a bird won't even need to be in view. I could even tack up an optometrist's chart a hundred feet away.
Or just focus on a detail of a tree? Here's a photograph of the woodpecker's suspected nest (taken with a Nikon D60, using its 55-200 mm lens):
|Note the two big holes in the center of the photo|
But perhaps the fieldscope focus was fine and the strong wind blurred the image a bit (relative to shutter speed)? The three photos of the Finch were taken in just a few seconds, and you can see the different positions of the surrounding twigs and tendrils.