Tele Vue 76 - Manual (Page 2)

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 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.
1.4 Photography
For prime focus photography at 480mm f/6.3 using a 35mm SLR, 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 focal length options. Afocal photography can be done using our various digital
camera to eyepiece adapters. For Piggyback 35mm SLR 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 motorized
focusing and the Focusmaster permits remote PC focusing via ASCOM compliant focusing software. For
installation, setup and use of the Digital Micrometer Kit, Focusmate TM , Focusmate Driver and Focusmaster TM ,
see the instructions included with each.
1.5 Caring for the Tele Vue-76
Tele Vue-76 requires no special care. Treat it as you would any fine camera lens. Use the lens cap
when the telescope is being stored or not in use. The captive dew shield provides protection from glare,
helps protect the lens from dust or spray blown in by the wind and minimizes dew formation on the lens.
If dew forms on the lens during cold weather, it is best to use an electric hair dryer (on the lowest
setting) to gently warm it away. A few specks of dust will have no effect on the quality of the image, and
may be gently blown off with a squeeze bulb. Do not use compressed air cans to blow dust off any opti-
cal surfaces.
Fingerprints, however should be cleaned off. Though the anti-reflection coatings are durable, they
are easily scratched. The simplest cleaning method is to moisten a very soft, lint-free tissue, cloth, “Q-Tip”
or surgical cotton with a lens or glass cleaner and gently whisk away the stain. Do not apply any solutions
directly to the glass surfaces. After every cleaning stroke, use a fresh applicator. The fewer strokes the
better! Any residual “film” will not affect visual performance.
Collimation of your Tele Vue-76 has been locked at the factory. With reasonable care it will
remain aligned. However, rough handling can cause misalignment. WARNING: Do not loosen the but-
ton head screws in the front lens cell as this will cause misalignment. If necessary, contact Tele Vue for
re-collimation.