JavaScript seems to be disabled in your browser. For the best experience on our site, be sure to turn on Javascript in your browser.

Skip to Content

Shop

Telescopes

Telescopes View All

Popular Telescopes

Popular Telescopes View All

Smart Telescopes

Beginner Telescopes

Astrophotography Telescopes

Refractor Telescopes

Dobsonian Telescopes

Refractor Telescopes

Refractor Telescopes View All

Petzval Telescopes

Triplet Telescopes

Doublet Telescopes

Reflector Telescopes

Reflector Telescopes View All

Dobsonian Telescopes

Newtonian Telescopes

Ritchey-Chretien Telescopes

Cassegrain Telescopes

Catadioptric Telescopes

Catadioptric Telescopes View All

RASA Telescopes

Maksutov Telescopes

More Telescopes

More Telescopes View All

Solar Telescopes

Computerized Telescopes

Astrograph Telescopes

Spotting Telescopes

Telescope Bundles

Smart Telescopes

Astrophotography

Astrophotography View All

Cameras

Cameras View All

Deep Sky Cameras

Planetary Cameras

Mounts

Filters

Filters View All

Light Pollution Filters

Narrowband Filters

Planetary Filters

Specialty Filters

Color Correction & Minus Violet Filters

ND & Polarizing Filters

Skylight & Protective Filters

Optical Correctors

Imaging Accessories

Imaging Accessories View All

Filter Drawers & Wheels

Camera Rotators

Adapters & Spacers

Collimation & Focusing Tools

Mounts

Mounts View All

Equatorial Mounts

Equatorial Mounts View All

Harmonic EQ Mounts

Classic GoTo EQ Mounts

Alt-Azimuth Mounts

Alt-Azimuth Mounts View All

GoTo Alt-Az Mounts

Manual Alt-Az Mounts

Telescope Mounts

Telescope Mounts View All

Mount Accessories

Mount Accessories View All

Telescope Tripods

Counterweights & Balancing

Dovetail Saddles & Clamps

Polar Scopes & Tools

Equatorial Wedges

Hand Controllers & Electronics

Screws, Knobs, & Hardware

Vibration Suppression

Miscellaneous Mount Accessories

Mounting Hardware & Solutions

Mounting Hardware & Solutions View All

Dovetail Bars/Rails

Dovetail Clamps

Hybrid Mounting Solutions

Solar

Solar Telescopes

Solar Telescopes View All

H-Alpha Telescopes

White Light Telescopes

Solar Binoculars

Solar Filters

Solar Filters View All

Solar Film Sheets

Ready-to-Use Telescope Solar Filters

Other Polymer Film Filters

Camera Lens Solar Filters

Herschel Wedges

H-Alpha Filters

Calcium H & K Filters

Other Specialty Filters

Solar Accessories

Solar Accessories View All

Solar Glasses & Viewers

Eyepieces & Barlows

Miscellaneous Accessories

Accessories

Accessories View All

Telescope Accessories

Telescope Accessories View All

Field Flatteners

Coma Correctors

Barlows & Extenders

Telescope Focusers

Focuser Accessories

Dew Prevention & Control

Finder & Guide Scope Accessories

Diagonals & Prisms

Eyepieces

Eyepieces View All

1.25" Eyepieces

Specialty Eyepieces

Imaging Eyepieces

Adapters

Adapters View All

0.965" Adapters

M54 Threaded Adapters

Baader UFC Adapters

Binocular Adapters

Camera / Imaging Adapters

Dust Covers / Seals

Eyepiece Adapters

Extension Tubes

Gender Changers

SCT Thread Adapters

Spacer Rings / Extenders

T-Thread Adapters

Webcam & Video Adapters

Miscellaneous Adapters

Binoculars & Accessories

Binoculars & Accessories View All

Standard Binoculars (Up to 50mm)

Large Binoculars (56mm-90mm)

Giant Binoculars (100mm & Larger)

Solar Binoculars

Binocular Accessories

More Accessories

More Accessories View All

Lights & Laser Pointers

Maps, Books & Software

Cleaning Supplies

Agena Astro Apparel & Merchandise

Miscellaneous Accessories

Power Adapters, Cables & Batteries

Dust Covers & Seals

Mirrors & Holders

Smart Telescope Accessories

Accessory Packages

Clearance

Clearance View All

Cameras

Eyepieces

Optical Accessories

Parts & Accessories

Telescopes

Binoculars

Sales & Special Offers

Sales & Special Offers View All

Celestron C-Suite EQ Promo

iOptron Mount Closeout Special Offer

Sky Watcher Mount Madness Sale

Sky-Watcher Refractor Sale

Contact/Visit Us
Shipping FAQ
Return Policy
Rewards Program
Privacy Policy
Customer Experience
Help

Compare Products item items

Sign In Create an Account

Telescopes
Astrophotography
Mounts
Solar
Accessories
Clearance
- Cameras Eyepieces Optical Accessories Parts & Accessories Telescopes Binoculars
Sales & Special Offers
- Celestron C-Suite EQ Promo iOptron Mount Closeout Special Offer Sky Watcher Mount Madness Sale Sky-Watcher Refractor Sale

Over 30k 5-star reviews
Free shipping over $50*
Easy 30-day returns

Shopping Cart

Loading...

More Telescopes

Category Solar Telescopes image

Solar Telescopes

Category Computerized Telescopes image

Computerized Telescopes

Category Astrograph Telescopes image

Astrograph Telescopes

Category Spotting Telescopes image

Spotting Telescopes

Category Telescope Bundles image

Telescope Bundles

Category Smart Telescopes image

Smart Telescopes

Filters (3)

William Optics

901 - 1000mm

Intermediate

Clear All

Sort by:

FILTER BY

Stock

Out of Stock (1) item

Manufacturer

Celestron (1) item
GSO (1) item
Sky Watcher (1) item
Takahashi (2) items
William Optics (1) item

Telescope Focal Length

Up to 300mm (3) items
301 - 400mm (1) item
401 - 500mm (9) items
501 - 600mm (2) items
901 - 1000mm (1) item

Experience Level

Intermediate (1) item

FILTER BY

Sort by:

William Optics Pleiades 181mm f/5.5 Astrograph Telescope

$19,998.00

Out of Stock

Out of Stock

1 Item

Show:

24
48
72

Free Shipping

on orders over $10*

30 Days Returns

from day of receipt

Live Inventory

for all products

Sign up for Agena Astro emails

Be first to know about sales, new astro gear & events

CONTACT

[email protected]

* Not A Retail Store *

13100 Alondra Blvd, Suite 106
Cerritos, CA 90703, USA

ACCOUNT

Log in
Create Account
Order Status
Order History
Wishlist

SUPPORT

Contact Us
Ordering FAQ
Shipping & Delivery
Returns & Exchanges
International Orders
Coupons & Discounts

RESOURCES

Affiliate Program
Agena Academy
Site Map
Discontinued Products

WHO WE ARE

About Us
Job Openings
Customer Reviews
Media Kit

Copyright © 2003-%d Agena AstroProducts. All rights reserved.

Terms of Use
Privacy Policy
Cookie Policy