4.7.2.l.4 Image tilt. With the panoramic telescope and fixture
positioned as outlined in 4.7.1, image tilt shall be observed by sighting
through Collimator F5549108 aligned to the optical axis of the eyepiece
assembly and note parallelism between its vertical reticle line and the
vertical line of the collimator target. Both lines shall be parallel
within the limits provided on the projected target (collimator reticle)
to assure conformance with the 3.7.2. Repeat this test with the elbow
assembly against each of the stops to assure conformance with 3.7.2.
Again observe parallelism between the reticle lines. Repeat this test at
eight different azimuth counter settings in 6400 mils of rotation. Each.
setting in azimuth will require the azimuth fixture plate to be rotated
an equal amount in an opposite direction to permit re-establishing the line
of sight to the position observed in 18.104.22.168.2. All readings are to be
within the limits outlined in 3.7.2.
22.214.171.124.5 Parallelism of image and reticle.- With the panoramic
telescope positioned as outlined in 4.7.1, align one end of the instrument
vertical reticle line to the projector collimator's vertical reticle line
and observe where the opposite end of the panoramic telescope vertical
reticle line falls with respect to the projector collimator vertical reticle
line. Both lines must coincide within the limits specified in 3.7.3. Repeat
this procedure with elbow assembly against each of the extreme stops. Also
repeat this procedure at approximately eight different azimuth settings in
6400 mils of-rotation. Return the line of sight to the projector collima-
tor's target line after each selected azimuth setting by rotating the
azimuth fixture plate an equal amount in the opposite direction. All
check points are to be within the limits outlined in 3.7.3.
126.96.36.199.6 Eyepiece focus.- This test is to be accomplished by
placing a white background in front of the panoramic telescope window.
Eyepiece focus is to be measured using a 3 power dioptometer conforming to
the accuracies depicted on Drawing 7680631. Adjust the dioptometer eye-
piece assembly to the dioptometer's reticle until a clear sharp image
appears on the dioptometer's optical axis. Next direct the dioptometer's
line of sight toward a 500 feet distant target such as a smoke stack, edge.
of a building, or some other well defined target image. Adjust the
objective assembly until parallax is removed and set the diopter scale to
zero. Parallax is defined as any apparent movement between the reticle and
target image when the head is moved from side to side or up and down.
Align the dioptometer's optical axis to the panoramic telescope optical
axis and obtain a clear sharp image of the panoramic telescope reticle on
the optical axis. Make all measurements on the dioptometer by adjusting
the objective assembly. Any and all adjustments to be within the limits
188.8.131.52.7 Parallax.- Using the set-up outlined in 4.7.1, parallax
will be tested a distances specified in 3.7.9 has been set into
the projector collimator. The test is performed by aligning a reticle
line or mark near or on the optical axis of the telescope under test to