Orion 90mm f/10.1 refractor Instruction Manuals

INSTRUCTION MANUAL

Orion® 90mm

f/10.1 Refractor

#9190

Providing Exceptional Consumer Optical Products Since 1975

Customer Support [phone]
E-mail: [e-mail]

Corporate Offices [phone]

89 Hangar Way, Watsonville, CA 95076

IN 310 Rev. B 02/09

Welcome to a new world of adventure! Your Orion 90mm f/10.1 Refractor is a fine-quality instrument designed for both daytime

terrestrial viewing and nighttime stargazing. This versatile scope will provide many hours of enjoyment for the whole family.

These instructions will help you set up and properly use and care for your telescope. Please read them over thoroughly before
getting started.

Dew/Glare shield

Tube rings

Dovetail tube ring mounting plate

WARNING: Never look at the sun with your

telescope (or even with just your eyes) without a
professionally made solar filter. Permanent eye damage
or blindness could result. Young children should use
this telescope only with adult supervision.

Avoid using the type of solar filter that screws into
an eyepiece. They are susceptible to cracking under
the intense heat that builds up near the focus point,
and could cause severe retinal damage. Use only
the type of solar filter that covers the front of the
telescope. Also, be sure to leave the cover caps on
the finder scope when solar observing. Better yet,
remove the finder scope altogether when viewing
the sun.

Finder scope

Finder scope

bracket

Eyepiece (25mm)

Focus wheels

Correct-image diagonal

Figure 1. The 90mm f/10.1 refractor.

Parts List

Qty. Description

1 Optical tube assembly

1 25mm Sirius Plössl eyepiece (36x)

1 10mm Sirius Plössl eyepiece (91x)

1 45° Correct-image diagonal, 1.25"

1 6x26 Correct-image finder scope

1 Finderscope bracket with O-ring

1 Dovetail tube ring mounting plate

2 Tube rings with mounting hardware

1 Objective lens cap

2

Focus
lock-ring

Alignment thumbscrews

Tensioner

Figure 2a. The 6x26 correct-image finder scope and bracket

Getting Started

The 90mm refractor comes nearly fully assembled from the
factory. The telescope’s optics have been installed and col­limated, so you should not have to make any adjustments to
them. Open the box and inspect the contents to make sure
all of the items in the parts list are present.

Please keep the original shipping box. In the unlikely event
you should need to ship the telescope back to Orion for war­ranty repair service, you should use the original packaging.
The box also makes a very good container for storing the
telescope when it is not in use.

Installing the Finder Scope

To place the finder scope in the finder scope bracket (Figure
2a.), first unthread the two black nylon thumbscrews until
the screw ends are flush with the inside diameter of the
bracket. Place the O-ring that comes on the base of the
bracket over the body of the finder scope until it seats into
the slot on the middle of the finder scope. Slide the eye­piece end (narrow end) of the finder scope into the end of
the bracket’s cylinder opposite the adjustment screws while
pulling the chrome, spring-loaded tensioner on the bracket
with your fingers (Figure 2b.) Push the finder scope through
the bracket until the O-ring seats just inside the front open­ing of the bracket’s cylinder. Now, release the tensioner and
tighten the two black nylon screws a couple of turns each to
secure the finder scope in place. Secure the bracket to the
dovetail mount on the optical tube with the knurled thumb­screw on the dovetail mount.

Installing the Diagonal and Eyepiece

Insert the 45° correct-image diagonal into the focuser draw­tube and secure it with the knurled thumbscrew on the
drawtube. Then insert the 25mm Sirius Plössl eyepiece into
the diagonal and secure it in place with the thumbscrews on
the diagonal. (Always loosen the thumbscrews before rotat­ing or removing the diagonal or an eyepiece.)

Figure 2b.

Mounting the Telescope

The 90mm refractor can be easily mounted on altazimuth
mounts, like the Orion VersaGo, which utilize a dovetail hold­er. Attach the included tube rings to the dovetail mounting
plate with the included hex head screws. Be sure to place a
lock washer and then a flat washer onto each screw before
attaching. Insert the screws (with washers) through the
holes in the plate and thread them into the base of the tube
rings (Figure 2c). Tightening the screws requires a 10mm
crescent wrench or an adjustable crescent wrench. Place
the optical tube into the open rings. Close the rings, and
use the silver clamping knob on each tube ring to secure
the telescope. The dovetail mounting plate now connected
to the 90mm refractor connects directly to the VersaGo’s
dovetail holder.

Figure 2c. Attaching the dovetail mounting plate.

The 90mm refractor can also be mounted on Orion equatorial
mounts using the dovetail mounting plate. Follow the previous
directions to couple the telescope to the mounting plate with
the tube rings.

An equatorial mount is desirable for astronomical viewing
as it allows easy manual and/or motorized tracking of celes-

Inserting the finder scope into the finder scope bracket.

Piggyback camera adapter

Tube ring clamping

knobs

Flat washer
Lock washer

Dovetail
mounting

Hex head screws

plate

3