Tele Vue 85 - Manual (Page 2)

Getting Acquainted with Your New Tele Vue-85
1.1 Optical Tube Assembly
The OTA consists of the objective cell, tube and focuser. The front cell houses the carefully aligned ob-
jective. 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 1:1
knobs on both the left and right sides, and a 10:1 reduction knob only on the right side. The two tension
screws on the top of the focuser body can be adjusted to add resistance when using heavy eyepieces.
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 11x to 200x, with the Tele Vue-85. We
recommend 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 600mm f/7 using a 35mm SLR, use camera adapter (part# ACM-2000).
For flat field astrophotography at 480mm f/5.6, use the Tele Vue 0.8x reducer/flattener, (part# TRF-2008).
Tele Vue Powermates with optional T-ring adapters provide a variety of options for extending focal length.
To reach focus with the Powermates requires our 3.5” extension tube. 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-85
Tele Vue-85 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.