WILLIAM OPTICS FLT91 Apochromatic Refractor Fluorostar Instruction Manual
- June 19, 2024
- WILLIAM OPTICS
Table of Contents
FLUORO STAR 91
MANUAL
WILLIAM0PTICS.C0M/FLU0R0STAR-91
FLT91 Apochromatic Refractor Fluorostar
Warning
Never aim your telescope or finder scope at the Sun without proper Solar
filters installed on the front of the telescope. Doing so for even a moment
may permanently damage your vision. Proper Solar filters consist of filters
made by reputable manufacturers, designed to fit tightly over the front of the
dew shield. Solar eyepiece filters are not considered safe, and should not be
used. With proper front mounted Solar filters, the telescope will not be
harmed by viewing the Sun.
SPECIFICATION
- Focal Length : 540mm
- Diameter: 91 mm
- Aperture: f/5.9
- Focuser: 3.3″ R&P Focuser
- Image Circle : >43mm
- Retracted Length : 44 1 mm
- Extended Length : 51 0mm
- Dew Shield Circumference : 383mm
- Dew Shield Diameter : dl 2 2 mm
- Weight : 9.1 Bibs / 4.165kg (OTA only)
12.29Ibs / 5.575kg (OTA with ring, dovetail and saddle)
Spot Diagram
Longitudinal Aberration
NOTE:
We are using a new lens cell design that includes FP53 glass in the WO triplet
series (GT and FLT series). This design is perfect for temperature
compensation to better prevent pinched optics, that can occur in cold weather
conditions.
Before storing your telescope, you must leave it uncovered, with the tube
opened for enough time to allow it to adjust to the room temperature. You must
make sure the telescope is completely dry of any dew or moisture before it can
be safely stored.
The telescope should always be stored in a dry location, with a consistent
temperature.
PACKAGE CONTENTS
A. Bahtinov Mask
B. OTA
C. 120mm Saddle Handle Bar
D. Visual Extention Tube
E. 2″ Rotolock Visual Back Adapter
F. Long Version Vixen-style Dovetail Plate
G. Soft Carry Case
PARTS
A. 2″ RotoLock Visual Back Adapter
B. Visual Extention Tube
C. Camera Angle Rotation Locking Screw
D. Dual Speed 3.3″ R&P Focuser
E. Focuser Rotation Locking Screw
F. Mounting Rings/ Knobs
G. 120mm Saddle Handle Bar
H. Dew Shield Locking Screw
I. Dew Shield| J. Lens Cover with Bahtinov Mask
K. Camera Angle Rotator
L. 10:1 Ratio Fine Knob & Cap
M. Long Version Vixen-style Dovetail
N. Locking Screws on Saddle Handle Bar (M4)
0. M4 Screw Holes
P. M6 Screw Holes
Q. Focuser Adjusting Knob with Thermometer
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TELESCOPE DIAGRAM
R & P GEAR SPACING SCREWS
Adjustment Screws (3 mm Allen Key) – Pull Screw
Adjustment Screws (2 mm Allen Key) – Push Screw
Can be Removed to Attach the Electronic Motorized Device such as EAF (Please
refer to the instructions on page 12
Tension Screw (Please refer to Note 2)
Do Not Touch
IMPORTANT NOTE:
- The focuser smoothness adjustment ONLY when necessary by progressively push & pull screws until you reach the desired smoothness.
- When using the telescope with the motor, please ensure that the tension screw is not over-tightened. Over-tightening the tension screw may cause damage to the focuser.
Think of it like driving a car and pressing the gas pedal while also pressing the brake simultaneously. Just as this action could harm your car’s systems, over-tightening the tension screw could compromise the functionality of your telescope’s focuser.
OPERATION GUIDE
How to Connect the Flattener
Step 1.
Remove the visual extention tube by unscrewing it from the focuser.
Step 2.
Connect the flattener to the focuser by screwing it on to the M92 thread.
How to Connect the FLAT68III
Step 1.
Remove the visual extention tube by unscrewing it from the focuser.
Step 2.
Connect the FLAT68 III to the focuser by screwing it on to the M92 thread.
Step 3.
Remove the original shorter adjusting adapter from Flat68 III and replace it
with the longer one (optional, for FLT91 only).
How to Install EAF
Step 1.
Remove the top screw with 2mm Allen key.
Step 2.
Release two inner knob screws.
Step 3.
Remove the knob.
How to Install EAF
Step 4.
Align the screw holes.
Step 5.
Lock two set screws on shaft.
Step 6.
Tighten both bracket screws.
ACCESSORIES MAP
Vistit W.O. webpage for details by Scanning the QR Code of the products
