Here is a step-by-step process of my two-handed approach to achieving sharp images when digiscoping birds that just won't sit still! My right hand is on the camera and my left hand is on the spotting scope. My right index finger controls the shutter, which can perform two important things:
My left index finger can still control the scope's focuser, while the other fingers maintain a grip on part of the scope body and tripod head.
This method has given me a lot of focusing control for tracking and digiscoping birds that are on the move.
With a micro-fluid head set to the appropriate tension, both hands can quickly maneuver the spotting scope to follow a moving bird.
Some digital cameras have an auto focus mode called Area Mode that can be set to manual. When enabled, it activates a user-selectable five area display that looks something like the digital camera here. Ignoring the vignetting in this example image, you can see how I've selected the auto focus area in the red bracket to apply to the bird's face.
Article and photos contributed by Mike McDowell, an avid digiscoper, amateur naturalist, and Eagle Optics employee. Visit Mike's Birding and Digiscoping Blog.