The Tele Vue Tunable Top with a 1.25-inch Adapter (model #TE-ATT-2125) is the tunable top version of the standard 2-inch Paracorr Type 2. It lets the user position all eyepieces for optimum coma correction. For use on the BIG Paracorr, the "VISA" (Visual/Imaging System Adapter, sold separately) is required. A 3-inch Tunable Top is not required since secondary mirror size limits maximum exit pupil diameter to around 7 mm. Therefore, the widest true field eyepiece choice with an f/3 is the Tele Vue 21 mm Ethos eyepiece, which delivers a 6.1 mm exit pupil at f/3.45.
To use the TE-ATT-2125 2-inch Tunable Top by Televue, just remove the stop flange from the Big Paracorr, attach the VISA adapter (TE-AVI-3200) adapter to the top of the Big Paracorr Type 2 and then screw the Tunable Top on top of this adapter. However, the Televue TE-ATT-2125 2-inch Tunable Top will attach directly to a 2-inch Paracorr. Then adjust the sliding lever on the side of the Tunable Top barrel to position your eyepiece according to the chart which is provided by Televue, to obtain the optimum coma correction. The included 1.25-inch Adapter can be inserted into the top of the TE-ATT-2125 if needed for your task.
For imaging with a DSLR or a CCD Camera, if you have a 35 mm format DLSR or CCD camera, the "VISA" adapter accepts Tele Vue Imaging System accessories.
OPT Product Number: TE-ATT-2125