The Nikon FSB-3 can only be used with Nikon digiscoping eyepieces, which have been specially modified to interface with the FSB-3. With the 50mm, 60mm, and 82mm Fieldscopes, the Nikon digiscoping eyepieces are our part numbers #N24WDE, #N40WDE, and #N60WDE. With the 65mm and 82mm ProStaff spotting scopes, the Nikon digiscoping eyepieces are our part numbers #N20PDS and #NPZDS.

The Nikon FSB-3 consists of an L-shaped camera bracket, a cable release, an adapter ring to allow the use of the physically shorter #N24WDE (the other eyepieces do not need the adapter due to their greater length), press-on non-skid pads to assure good contact between your camera shutter and the cable release, and instructions.

Your camera is mounted on the L-base of the bracket, with its lens protruding into the black eyepiece socket ring. The rubber eyeguard is removed from your digiscoping eyepiece to reveal the groove around its top. With the eyepiece installed on your scope, your camera and FSB-3 are slipped onto the eyepiece and locked in place with a thumbscrew in the side of the eyepiece socket ring. The thumbscrew engages the groove on the eyepiece to keep the camera from falling off the scope accidentally.

Roughly focus on your subject using your scope’s focus knob, observing the focus on your camera’s LCD display, then let the camera’s autofocus mode make the fine adjustment. Gently trip the shutter using the FSB-3’s cable release.

Because you are shooting through both the scope’s eyepiece and the camera’s zoom lens, the combination of magnifications makes for very high magnification images, hence the use of the term “super-telephoto” in Nikon’s instruction sheet for the FSB-3. The exact magnification will depend on the magnification of the eyepiece being used and the zoom setting of the camera, but in all cases it will be high enough to require a very sturdy tripod and the use of the supplied cable release to keep the images from being blurred by camera vibration.

When shooting with your camera zoom at its wide-angle setting, there may be darkening of the image at its four corners (vignetting), giving the image a rounded appearance. You can use your camera lens to zoom in on the center of the image to eliminate the vignetting.