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William Optics Pleiades 111 Astrograph F/4.8 7-element WIFD
William Optics Pleiades 111 Astrograph F/4.8 7-element WIFD
William Optics Pleiades 111 Astrograph F/4.8 7-element WIFD
William Optics Pleiades 111 Astrograph F/4.8 7-element WIFD
William Optics Pleiades 111 Astrograph F/4.8 7-element WIFD
William Optics Pleiades 111 Astrograph F/4.8 7-element WIFD
William Optics Pleiades 111 Astrograph F/4.8 7-element WIFD
William Optics Pleiades 111 Astrograph F/4.8 7-element WIFD
William Optics Pleiades 111 Astrograph F/4.8 7-element WIFD

William Optics Pleiades 111 Astrograph F/4.8 7-element WIFD

by William Optics
SKU WO-T-P-111BU
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CA$5,793.00
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CA$5,793.00
CA$5,503.00
CA$5,503.00 - CA$5,503.00
CA$5,503.00
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  • 111mm Aperture 7-Element Astrograph
  • 528mm Focal Length at a fast f/4.8
  • 45mm Image Circle for Full-Frame Sensors
  • William Optics Internal Focus Design (WIFD)
  • Integrated Rotator and Tilt Adjuster
  • 55mm Required Back Focus
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  • Description
  • FAQ
  • Specifications
  • In the Box
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  • Warranty

  • William Optics Pleiades 111 Astrograph F/4.8 7-element WIFD

    The William Optics Pleiades 111 Astrograph is a 111mm, 528mm, f/4.8 imaging apochromat with seven elements, three of them Super ED glass. Its 45mm image circle covers full frame and no flattener is required. Focus comes from the patented William Optics Internal Focus Design (WIFD), and with rings, dovetail and saddle it weighs 10.31 kg.

    What the Pleiades 111 Is For

    The Pleiades 111 is a 7-element imaging APO telescope designed for serious astrophotographers, with an internal focusing mechanism and apochromatic optics with FPL-53 glass, built for large, high-resolution cameras.

    Its 528mm focal length sits between wide-field and medium-scale imaging: large galaxies, nebula complexes and star clusters with more image scale than shorter astrographs.

    Septuplet Optics with 3 Super ED Elements

    It is a 7-element astrograph with Super ED glass x3, and the septuplet optical system delivers sharp, vibrant images with minimal chromatic aberration. A new lens cell design in the Pleiades series uses high-quality FPL-53 glass.

    The manual includes a full-frame spot diagram and a longitudinal aberration plot for the Pleiades 111 at f/4.8.

    111mm Aperture at f/4.8

    A 111mm objective has a Dawes limit of about 1.05 arcseconds. With a full-frame sensor, 528mm gives about 3.9 x 2.6 degrees; with APS-C (about 23.5 x 15.6mm) about 2.5 x 1.7 degrees.

    At f/4.8 each sub-frame needs roughly half the exposure of an f/7 instrument for the same signal.

    A 45mm Image Circle for Full-Frame Sensors

    The image circle is ">Full Frame (45mm)", which covers the 43.3mm diagonal of a 36 x 24mm sensor. Supported formats are full frame, APS-C and M4/3, with T-mount support for Canon EF and RF, Nikon F and Z, Sony E, Pentax K, MFT and FUJI X.

    WIFD Focuser: 35mm of Travel

    The focuser is the WIFD (WO Internal Focus Design), patented and compatible with EAF, with 0 to 35 mm of travel and a ruler to 50. It has a 2 speed 10:1 ratio fine knob and a focuser adjusting knob with a thermometer. The internal focusing system, with the camera angle rotator and tilt adapter, ensures stability and ease of use with large imaging setups.

    • Tension: tension screws (5mm Allen key) increase focuser tension. Do not over-tighten the focuser tension screw, and release it when focusing.
    • Smoothness: push and pull gear spacing screws (3mm and 2mm Allen keys), adjusted only when necessary.
    • EAF: remove the top screw (2mm Allen key), release the two inner knob screws, remove the knob, align the screw holes, lock the two set screws on the shaft and tighten both bracket screws. With a motor fitted, do not over-tighten the tension screw.

    55mm Back Focus, Rotator and Tilt Adapter

    The manual's drawing gives 55mm from the M48x0.75 (or M54x0.75) camera thread to the camera sensor. M48 and M54 camera adapters are included.

    • Camera angle rotator: with a locking screw, for framing.
    • Tilt adapter: adjusted with alternating push and pull screws using a 1.5mm Allen key.
    • Filters: the accessories map lists the STC Astro-Multispectra and Astro Duo-Narrowband filters.

    Visual Use

    William Optics presents the Pleiades 111 as an imaging telescope and does not describe a visual configuration. Ask us before buying a diagonal or eyepieces for it.

    Build: Dew Shield, Bahtinov Mask, Rings and Saddle Handle Bar

    The dew shield retracts and has a lock screw; it is 155mm across, and the front dust cover with its Bahtinov mask threads on at M156. The tube sits in mounting rings with knobs on a Losmandy Style Type D mounting plate.

    • Saddle handle bar: M4 locking screws and M4 and M6 screw holes for a finder bracket; remove the two finder bracket holder screws (2.5mm Allen key) before use.
    • Guide scopes: the manual's accessories map shows the M-GS61RD GuideStar 61 (optional) and the M-G50PB-TG UniGuide 50, plus a red dot sight.

    Weight, Length and Case

    The optical tube weighs 7.955 kg (17.54 lbs), and 10.315 kg (22.74 lbs) with ring, dovetail and saddle. Length is 645mm with the dew shield retracted and 785mm extended. A soft carry case is included. Add your camera and accessories and compare the total with your mount's rated payload.

    First Light and Care

    Mount the telescope by its Losmandy-style plate, attach the camera at 55mm from the M48 or M54 thread, fit the Bahtinov mask cover and focus on a bright star with the tension screw released.

    Before storing it, let it acclimatise to room temperature with the tube uncovered and open, and make sure it is dry and free of dew. Store it in a consistent-temperature, dry place. Never aim the telescope or finder 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. Solar eyepiece filters are not considered safe.

  • Do I need a separate flattener for the William Optics Pleiades 111?

    No. This 7-element astrograph needs no flattener.

    What does the WIFD focuser offer on the Pleiades 111?

    35 mm of travel, a 2 speed 10:1 fine knob, a thermometer on the adjusting knob, adjustable tension and smoothness, and EAF compatibility with the fitting steps in the manual.

    How does 528mm frame the Andromeda Galaxy (M31)?

    On full frame, 528mm covers about 3.9 x 2.6 degrees, so M31 (about 3 degrees long) fits across the long side with little room; on APS-C (about 2.5 x 1.7 degrees) it needs a two-panel mosaic.

    Does f/4.8 suit narrowband imaging of the Cygnus Loop?

    Narrowband filters pass little light, so a faster focal ratio helps. At 528mm and full frame the field is about 3.9 x 2.6 degrees, which takes in one side of the Veil (Cygnus Loop) at a time.

    What mount does the Pleiades 111 need?

    The telescope weighs 10.315 kg with ring, dovetail and saddle. Add your camera and accessories and choose a mount with a Losmandy D saddle whose rated payload covers the total with margin.

    What do the tilt adapter and camera rotator do?

    The rotator turns the camera for framing and locks with a screw. The tilt adapter corrects tilt between the sensor and the focal plane, using alternating push and pull screws and a 1.5mm Allen key.

    Can I attach an EAF to the Pleiades 111?

    Yes. Remove the top screw with a 2mm Allen key, release the two inner knob screws, remove the knob, align the bracket screw holes, lock the two set screws on the shaft and tighten both bracket screws. Do not over-tighten the tension screw with a motor fitted.

    How do I use the Bahtinov mask?

    Fit the front dust cover with the mask, aim at a bright star, and adjust focus until the central diffraction spike sits centred between the other two.

    What is the back focus for the Pleiades 111?

    55mm from the M48x0.75 (or M54x0.75) camera thread to the sensor.

    Can I use the Pleiades 111 for visual astronomy?

    William Optics does not describe a visual configuration for it. Ask us before buying a diagonal or eyepiece.

  • Optical Design 7-Element Astrograph with 3x Super ED Glass Elements
    Aperture 111 mm
    Focal Length 528 mm
    Focal Ratio f/4.8
    Image Circle 45 mm
    Focuser WIFD Rack & Pinion Internal Focuser
    Focuser Travel 35 mm
    Flattener Required No
    Camera Support Full Frame, APS-C, M4/3
    Included Camera Adapters M48, M54
    Dovetail Losmandy-D Style
    Tube Length (Retracted/Extended) 645 mm - 785 mm
    OTA Weight 7.95 kg / 17.53 lbs
    Total Weight (inc. rings/dovetail) 10.31 kg / 22.73 lbs
    Required back focus (native, with built-in corrector) 55mm
    Mount No

    • Pleiades 111 OTA

      × 1

    • Dust Cover with Bahtinov Mask

      × 1

    • Mounting Rings

      × 2

    • Saddle Handle Bar

      × 1

    • Losmandy Style Type D Mounting Plate

      × 1

    • Camera Angle Rotator

      × 1

    • Tilt Adjuster

      × 1

    • M48 Camera Adapter

      × 1

    • M54 Camera Adapter

      × 1

    • Soft Carry Case

      × 1

  • William Optics 2-Year Warranty