Terrestrial Viewing Considerations - The Tele Vue 55mm Plössl in a 2” diagonal will provide 9x with a
5.5° true field. This can serve as a finder, for rich field viewing or for terrestrial use. (Image is upright, but
left-right reversed using diagonal mirrors.)
Tele Vue developed the 1¼” 60° Everbrite Diagonal (part# DPC-6012) specifically for terrestrial
observers who appreciate the highest levels of image performance. The 60° angle is far more comfortable
for terrestrial observing than the standard 90°, and the 99% reflective Everbrite dielectric coating gives the
truest color rendition of any mirror or prism, and is sharpest at the highest powers.
For 1¼” diagonals and prisms, the 32mm Plössl or 24mm Panoptic offer the maximum field. 3.2°
at 15x and 20x respectively.
Getting Acquainted with the
Tele Vue
-76 (see photos on page 3.)
Note: O.T.A. purchasers must supply eyepieces, eyepiece adapter, diagonal, and ring mount in order for
the telescope to function. TV-76 Accessory Package includes these items.
1.1 Optical Tube Assembly
The OTA consists of the objective cell, tube and focuser. The front cell houses the carefully aligned objective.
Never attempt to loosen the 3 alignment screws in the front lens cell. The tube is aluminum and powder
coated, requiring no special care. The rack and pinion focuser is driven by high leverage knobs. The two
tension screws on the top of the focuser body can be adjusted to add resistance when using heavy eye-
pieces. These tension screws tighten against a brass clamp ring, which then cinches down on the teflon
sleeve in which the draw tube slides. For photography it is not necessary to tighten beyond the need to
keep a camera stationary. Even when sufficiently tight, the focuser knobs can still drive the draw tube.
The two lock screws in the end of the draw tube also tighten against a brass clamp ring for extra holding
power on the diagonal or other accessories.
1.2 Ring Mount
The Ring Mount included with the TV-76 Accessory Package permits easy telescope balancing. Simply
unlock the “bat handle,” reposition the telescope by sliding it fore or aft, and re-lock. Slots with 10-32
holes are available for mounting accessories.
1.3 Eyepieces
Tele Vue eyepieces offer a range of magnifications from 9x to 200x, with the
Tele Vue-76
. We recom-
mend choosing low and medium power eyepieces in ratios of field stop diameters. For example, factors
of 1.4 or 2.0. When choosing higher power eyepieces, use ratios of magnification. (see reference chart
in the “Choosing Your Eyepieces” article). The TV-76 Accessory Package includes an 18.2 DeLite that
offers a 2.3° true field at 26x magnification with 20mm of eye relief.
1.4 Photography
For prime focus photography at 480mm f/6.3 using a DSLR, use camera adapter (part# ACM-2000).
For flat field astrophotography at 380mm f/5, use the Tele Vue 0.8x reducer/flattener, (part# TRF-2008).
Alternatively, the Tele Vue Powermates with optional T-ring adapters and our 3.5” extension tube provides
a variety of focal length options. Afocal photography using your cell phone camera is accomplished with
FoneMateTM (part# SFA-001). For Piggyback DSLR photography, attach the Piggy-Cam platform, (part#
PGC-1001) to the Ring Mount.
Mounting points are provided on top of the focuser body and draw tube for easy installation of the
Digital Micrometer Kits (part#s RMK-2002 or RMF-2003). These kits allow imagers to index focus posi-
tion to within 0.0001”, providing a very convenient way of finding best focus, returning to it, or checking
that it hasn’t changed. The dual speed focuser with its 10:1 focus reduction provides extraordinarily fine
focus adjustment for critical focusing. The Focusmate Driver (part# FDF-2004) adds hands free motor-
ized focusing. For installation, setup and use of the Digital Micrometer Kit and Focusmate Driver, see the
instructions included with each.
