Televue 3.5" Extension Tubes

The Van Slyke MegaPort SideWinder has provision for two (2) ports in addition to the off-axis guider port (top) and the main imaging port (rear), were the main QSI 516 ws CCD camera (blue) is located. These two other ports are presently used to accept 2" eyepieces, but because of the back-focus necessary to reach the main CCD imaging plane, the two eyepiece ports in question require extension tubes to bring the eyepieces into focus. I opted for the TeleVue 3.5" long extension tubes (X3C-0009) to accommodate my TeleVue 17 and 31 mm Naglers. These extension tubes are very well made, and have brass clamp rings to secure (with two thumbscrews) the eyepiece, thereby avoiding a marring to the eyepiece tubes due to metal securing screws. The photo shows the 31 and 17 mm Naglers in each of their extension tubes on the left and right, respectively.  Combined with the Van Slyke MegaPort SideWinder, these extension tubes provide a "weld-like" connection for the eyepieces.