ORION TELESCOPES & BINOCULARS Tele-Extender 5125 User manual

IN 011 Rev. C 03/09
Orion Tele-Extender
#5125 Standard Tele-Extender
#5127 Variable Tele-Extender
Your Orion Tele-Extender will allow you to take high magnica-
tion photographs of celestial objects with a Schmidt-Cassegrain
telescope. It is particularly useful for planetary astro-photogra-
phy, close-ups of lunar craters, and extremely long distance
terrestrial photography.
How To Use The Orion Tele-Extender
The Standard Tele-Extender (A) is a xed-length extension
tube, which produces a xed magnication for a given eye-
piece used with the tele-extender. The Variable Tele-Extender
(B) has an adjustable-length extension tube, allowing magni-
cation to be changed without switching eyepieces.
For high-powered photography through your Schmidt-
Cassegrain, attach the visual back in the normal manner. Instead
of inserting the star diagonal into the visual back, insert an eye-
piece and hand tighten the set screw. Thread the tele-extender
onto the visual back, over the eyepiece. Thread your T-ring onto
the end of the tele-extender and attach your camera.
Some telescopes do not have a separate visual back, such as the
Meade LX5 series, LX6, and the Meade 2045. You may have to
purchase a visual back to use a tele-extender. A 1.25" visual back
which ts Meade and Celestron Schmidt-Cassegrain 4", 8", 10",
11", and 14" scopes is available from Orion (#15048). (Celestron
C-90s and some other small spotting scopes have threads that
will t a tele-extender directly but require the use of .965" eye-
pieces to create the higher magnications.)
Most standard eyepieces are useable with a tele-extender.
Some eyepieces have barrel assemblies that are too large to
t inside a tele-extender. See the diagram below for reference
on how to attach a tele-extender to your telescope.
When you look through your camera and focus the telescope,
you will notice a dim, highly magnied image. This is normal
when using a tele-extender. The eyepiece enlarges the image
and therefore reduces the amount of light. Shorter-focal-length
eyepieces magnify the image more, causing it to be dimmer.
Dimmer images mean longer exposure times will be necessary.
Focusing
It can be quite difficult to focus the telescope, especially when
using eyepiece projection! In fact, with most cameras the
image in the viewnder can be so dim that it may be difficult to
nd the focal point at all. Use a bright object such as the Moon
or a bright star for focusing. Find and center this object in the
telescope’s eld before installing the camera adapter.
Tele-Extender Effective Focal Length Chart
Below is a chart of effective focal lengths and f/ratios to assist
you in determining the best combinations for your system.
Values are rounded to the nearest 5 or 0 for convenience. For
the variable tele-extender, the effective focal length below
applies when the unit is fully extended. Shortening the vari-
able tele-extender will reduce the effective focal length.
Instrument 8" f/10 10" f/10 11"f/10
Base Focal Length 2000mm 2500mm 2800mm
Eyepiece
40mm 7000mm f/35 8700mm f/35 9800mm f/35
30mm 9500mm f/50 1200mm f/50 13100mm f/50
25mm 12000mm f/60 14000mm f/60 15700mm f/60
20mm 14000mm f/70 17800mm f/70 19600mm f/70
18mm 18000mm f/90 12000mm f/90 21777mm f/80
15mm 19000mm f/95 24000mm f/95 26500mm f/100
13mm *22000mm f/115 28000mm f/110 30600mm f/115
12mm *28500mm f/140 *30000mm f/140 *33000mm f/125
10mm *29000mm f/140 *36000mm f/145 *40600mm f/150
9mm *39000mm f/190 *40300mm f/165 *45000mm f/165
7mm *41000mm f/210 *52000mm f/210 *58000mm f/215
*Beyond useful magnication—not recommended
Schmidt-Cassegrain
Visual BackEyepieceTele-ExtenderT-RingCamera
A.
B.
Corporate Offices: 89 Hangar Way, Watsonville CA 95076 - USA
Toll Free USA & Canada: [phone]
International: [phone]
Customer Support: [email protected]
Copyright © 2021 Orion Telescopes & Binoculars.All Rights Reserved. No part of this product instruction or any of its contents
may be reproduced, copied, modied or adapted, without the prior written consent of Orion Telescopes & Binoculars.
AN EMPLOYEE-OWNED COMPANY
INSTRUCTION MANUAL

If your camera has interchangeable focusing screens, use
a ne-ground glass screen. It will be much brighter and will
make focusing easier.
Vibration During Exposure
It is very important to minimize vibration during an exposure. If
your camera is equipped with a “mirror lock-up,” use it before
you start the photo. Use a cable release to trip the self-timer
on the camera. To further reduce vibration, the best solution is
the “hat trick.” Set your camera’s exposer time (shutter speed)
to the “B” (bulb) setting, which will hold the shutter open inde-
nitely when triggered. Hold a black piece of cardboard or a “hat”
in front of the telescope (but not touching it) while you open
the shutter. Wait approximately 8 seconds and then remove the
“hat.” It is important that nothing touch the telescope or camera
during the exposure. When you're nished exposing, place the
“hat” in front of the telescope again and trip the cable-release
to close the shutter.
Precautions
Be very careful not to release the set screw holding the eye-
piece before removing your camera and tele-extender. If the
screw is released and the eyepiece falls through the extender
tube, it can damage your camera.
Corporate Offices: 89 Hangar Way, Watsonville CA 95076 - USA
Toll Free USA & Canada: [phone]
International: [phone]
Customer Support: [email protected]
Copyright © 2021 Orion Telescopes & Binoculars.All Rights Reserved. No part of this product instruction or any of its contents
may be reproduced, copied, modied or adapted, without the prior written consent of Orion Telescopes & Binoculars.
AN EMPLOYEE-OWNED COMPANY
One-Year Limited Warranty
This Orion product is warranted against defects in materials or workmanship for a peri-
od of one year from the date of purchase. This warranty is for the benet of the original
retail purchaser only. During this warranty period Orion Telescopes & Binoculars will
repair or replace, at Orion’s option, any warranted instrument that proves to be defec-
tive, provided it is returned postage paid. Proof of purchase (such as a copy of the origi-
nal receipt) is required. This warranty is only valid in the country of purchase.
This warranty does not apply if, in Orion’s judgment, the instrument has been abused,
mishandled, or modied, nor does it apply to normal wear and tear. This warranty gives
you specic legal rights. It is not intended to remove or restrict your other legal rights
under applicable local consumer law; your state or national statutory consumer rights
governing the sale of consumer goods remain fully applicable.
For further warranty information, please visit www.OrionTelescopes.com/warranty.