10
5
Flange focal distance
The flange focal distance is the distance between the sensor and the connection surface of the lens. C-mount is a standard
mount with an inch thread and a flange distance of 17.526 mm.
The Juno2 is fitted with a C-mount connection to mount the lens. That means that the correct flange focal distance is preset
when C-mount lenses are used. TV adapters of microscopes and endoscopes often provide fine adjustment for the correction
of the flange distance of the eyepiece and the sensor.
5.1
Check and adjust flange focal distance (zoom lens)
The flange distance is adjusted during manufacture. If you use a lens or a TV adapter with a different flange focal distance,
the image will be unsharp. In this case, the flange focal distance must be readjusted. Please proceed as follows:
Choose a suitable object in great distance, adjust the lens to maximum zoom (maximum focal distance) and focus the
image.
Zoom the lens to maximum wide-angle (minimum focal distance) without changing the focusing.
The flange distance is correct if the image remains sharp over the entire range of focal distances of the lens.
If the image is blurred at minimum focal distance (unchanged focusing), the flange distance has to be adjusted.
To adjust the flange distance, loosen the fixing screw (internal hexagon screw) on the rear side of the camera until you can
barely turn the lens mount (C-mount or CS-mount). Turn the lens mount of the camera until the image is sharp at minimum
focal distance. Repeat the test and correct again if necessary. Tighten the fixing screw to secure the adjustment.
5.2
Check and adjust flange focal distance (fixed focal distance lens)
Adjust the lens to infinity and check if the image is sharp. If the image is blurred, adjust the flange distance as described
above.
5.3
Check and adjust flange focal distance (microscope)
Make sure that the diopter compensation at the oculars is adjusted to 0. Adjust with the ocular until the object is sharp in
the ocular. Adjust the flange distance as described above if the object is not displayed sharply on the monitor at the same
time.
