2006 - Midwest Peregrine Falcon Restoration Project

57
lens when extended fits inside the scope eyecup a bit loosely. To make the fit more snugly, I put a
strip of thin leather four inches long and a quarter inch wide inside the eyecup as a bushing for the
camera lens
A sturdy tripod is essential and a remote shutter release is almost as essential. Any movement
of the camera during exposure is likely to ruin the image.
Given this equipment (and I eagerly await suggestions from anyone for equipment
improvements), how is it best used in the field First, the camera (my Nikon 8400, that is) should be
set on shutter control, which automatically opens autofocus. Then zoom it to its 3.5X optical limit to
avoid “vignetting”, an automatic framing of the scope image as viewed on the camera monitor at
lower camera magnifications. The zoom range of my telescope is 20X to 60X. For years I thought
that 40X to 50X produced the best result, usually a compromise between image size and image
readability. Recently, I have experimented with 60X, at the suggestion of Jackie Fallon, and find that
this works fine if the focus is precise. How precise With an image in clear focus at 60X on my
scope, moving the fine focus adjustment wheel either way less than a millimeter destroys the focus.
Focus the scope directly on the bird and then mount the camera, delicately. At 3.5X camera zoom
and 40X scope zoom, the net result is an image enlarged 140 times; at 3.5X and 60X, 210 times.
To minimize blurring by falcon or camera movements, shutter speed should be as fast as
provides a reasonably lighted image. With my equipment, shutter speeds of 1/125 th or 1/250 th second
seem to work best. Poor light may call for slower shutter speeds, enhancing the value of the remote
shutter release to avoid camera movement.
Given good light, patience, and a cooperative falcon that exposes its banded leg at least
occasionally, how far away should an image enlarged 140X or 210X be readable I tested the ability
of several people with good eyesight to read peregrine black/green bands in outdoor Minnesota