optical axis of the AF51 camera’s lens system and to ensure the exit pupil of the scope is
at the correct height for the camera so the camera sees the full field of view without
vignetting. Failure to make these adjustments correctly can result in no image being seen
at all or a very unevenly illuminated or small image being seen.
Types of adjustment available
The kind of adjustments that can be made are:
1. XY shift using the thumbscrews on the translation adjustable mount (see figure 3.9)
2. Angular tilt of the clamp on the eyepiece (see figure 3.15, right)
3. Height adjustment using either the clamp lock nut alone or accompanied by slipping the
clamp up on the body of the eyepiece (see figures 3.11 and 3.15, left).
Centring the optical axis
The first thing to do is centre circular eyepiece field of view in the rectangular camera
field of view. This is done with a
djustments 1 and 2 described above but because
adjustment 1 (XY shift) is already set at a nominal central position you should begin by
making angular adjustments till you catch the optical axis in the camera’s field of view
then make small corrective adjustments iterative in both shift and angle till the desired
result in achieved (see figure 5.6).
You should have the camera set to auto exposure mode and use a high frame
rate preview live image while doing this adjustment.
This is because you need real-
time visual feedback and the light levels entering the camera can change radically when
off axis compared to when on axis. Without the auto-exposure the camera preview image
may look completely black or completely white and so you will not be able to just
alignment.
OptArc AF51 Camera Page 57 of 99 User Guide v1.02
