The following photograph was captured with a C-14 OTA mounted on an EQ-2 mount. The mount was intentionally mis-aligned from the polar axis to create drift in the DEC axis so that the sinusoidal periodic error in the RA axis is made visible.

Note that the scale in red was added for clarity. The image is otherwise completely unretouched. The Full Size image also depicts a 2 arc second square box for comparison.
The image was shot at a focal length of aproximately 3910mm using Kodak 400ASA/ISO 35mm film at prime focus of a C-14. The image was exposed for 28 minutes and shows 7 periodic cycles of the worm assembly (4 min. each). The aproximate scale of the printed photograph was 12arc sec. per mm. The above portion represents about 1/3 of the full 35mm frame. Based upon inspection of the width of sinusoidal motion in the star streaks, approximately 3 arc sec(+/-) periodic error is visible.