William Optics

William Optics 40 mm Super Wide Angle 2" Eyepiece - E-SWA40
- Focal Length: 40 mm
- Apparent Field of View: 72

William Optics Soft Carry Case for GTF81 and GT81 - No Foam - BG1-P002
- Case/Cover Dimensions (LxWxH): 20.55" x 7" x 13.25" - External
- Known to Fit: William Optics GTF81 and GT81 Telescopes

William Optics 1.25" Dielectric Diagonal W/ Carbon Fiber Plates - D-125D-C-DB
- Diagonal Type: Mirror Diagonal
- Diagonal Size - Eyepiece Side: 1.25" Barrel
- Diagonal Size - Telescope Side: 1.25" Barrel
- Optics Type and/or Coatings: Dielectric Coatings

William Optics Binoviewer W/Eyepieces & Barlow Nosepiece - E-BINO-P
- For finetuning this William Optics Binoviewer has eyepiece focus adjustment.
- This WO binoviewer has fully-multi coated optical elements.
- Included with this Binoviewer are two William Optics 20 mm, 1.25" eyepieces.
- The use of non-marring compression rings protect the inserted eyepieces.

William Optics Soft Carry Case for Z71 - No Foam - BG1-P004
- Case/Cover Dimensions (LxWxH): 15.75" x 6.5" x 12.5" - External
- Known to Fit: William Optics Z71 Telescope

William Optics 9 mm Super Wide Angle 1.25" Eyepiece - E-SWA09
- Focal Length: 9 mm
- Apparent Field of View: 72

William Optics 1.25" 45° Erect Prism - D-EP125
- Diagonal Type: Correct/Erect Image
- Diagonal Size - Eyepiece Side: 1.25" Barrel
- Diagonal Size - Telescope Side: 1.25" Barrel

William Optics 20 mm Super Wide Angle 1.25" Eyepiece - E-SWA20
- Focal Length: 20 mm
- Apparent Field of View: 72

William Optics Soft Carry Case for FLT98, FLT110, GT102, GTF102 - No Foam - BG1-P001
- Case/Cover Dimensions (LxWxH): 30.315" x 13.7795" x 9.44882" (770mm x 350mm x 240mm) - External
- Known to Fit: William Optics FLT98, FLT110, GT102, GTF102 Telescopes

William Optics 1.25" 2x Barlow Nosepiece for Binoviewers - E-BINO-B2
- Using this Barlow nosepiece will double the power of the eyepieces used with the Binoviewers.
- The barrel of this William Optics Barlow is 1.25".
- William Optics' Barlow Nosepiece will screw into 1.25" eyepieces and binoviewers.
- Though not included, this 2x Barlow nosepiece can be used in conjunction with an extender.

William Optics 12.5 mm Super Planetary Long Eye Relief Eyepiece - E-SPL125
- Focal Length: 12.5mm
- Apparent Field of View: 55

William Optics 25 mm Super Wide Angle 2" Eyepiece - E-SWA25
- Focal Length: 25 mm
- Apparent Field of View: 72

William Optics 33 mm Super Wide Angle 2" Eyepiece - E-SWA33
- Focal Length: 33mm
- Apparent Field of View: 72

William Optics 90 mm Mounting Rings - M-M80R-B
- Type of Mounting Hardware: Rings Only
- Ring Size: 90 mm (3.5")
- Solid or Split (Cradle) Ring: Split or Cradle Ring(s)

William Optics Extender for FLT 110 & 132 Telescopes - P-EXFLT
- Adapter Connector Type - Side A: 3.5"
- Adapter Connector Type - Side B: 3.5"
- Adapter or Spacer Length in mm: 50 mm

William Optics STL CCD Camera Adapter - P-STL
- Adapter Connector Type - Side A: SBIG (2.156")
- Adapter Connector Type - Side B: M92

William Optics 800 mm Mortar Tri-Pier - Red - YG-MT-800-BR
- This William Optics tri-pier is made out of 6061T Aluminum and Stainless Steel.
- The maximum height of the tri-pier is either 800 mm.
- William Optics Tri-Pier is compatible with iOptron, Sky-Watcher, Crux, Takahashi, and Vixen mounts.
- Choosing this WO tripod means you will have the stability of a pier with the flexibility of a tripod.

William Optics Image Plane Tilt Adjuster for Cat51 Upgrade - M-FD-RC51
- Made for Cat Series Refractors
- Comes with a M48 Filter Thread
- Used as an upgrade for first generation Cat Series Scopes
- Includes push screws and pull screws


William Optics 1.25" RotoLock Adapter - Gold - F-ROTO-A2-125GDII
- This Rotolock adapter locks into the 2” opening of a WO Rotolock diagonal or focuser.
- This is a steppingstone to attaching 1.25” barreled accessories.
- Rotating the adapter ring will lock and unlock the inserted accessory into place.
- Using this adapter will ensure that your accessory is centered.

William Optics WhiteCat 51 APO f/4.9 Refracting Telescope - Limited Edition - L-RC51W
- Optical Design: Refractor
- Telescope Aperture: 51mm (2")
- Focal Ratio: f/4.9
- Telescope Mount Type: No Mount - OTA Only
- Type of Electronics: OTA Only - No Electronics

William Optics 48mm T mount for Fuji FX - Space Gray - YE-TR-M48FX-TG
- DSLR, SLR or Mirrorless Adapters by Brand: Fuji
- Threads: 48 mm T-Mount
- Construction Material: CNC-Machined Aluminum

William Optics Dura Bright 2" Carbon Dielectric Diagonal - D-DIG2D-C-DB-T
- Diagonal Type: Mirror Diagonal
- Diagonal Size - Eyepiece Side: 2" Barrel
- Diagonal Size - Telescope Side: 2" Barrel
- Includes Eyepiece Adapter: Yes, 2" to 1.25"
- Optics Type and/or Coatings: Dielectric Coatings

William Optics 0.8x Reducer/Flattener - P-FLAT7A
- This William Optics 0.8x reducer/flattener is adjustable for optimum back focus.
- Adjustment depends on the William Optics refractor with which the flattener is used.
- This flattner is meant to work with the FLT132, FLT156, GT102, GT153, and the Z126.
- The FLAT7A is compatible with several types of CCD and CMOS cameras.
- The flattener is produced with Ohara optical glass.

William Optics Cat Series Saddle Handle Bar - Space Gray - M-HCRC-TG
- Type of Mounting Hardware: Mount Adapters, Stalks & Accessories
- Color: Space Gray
- Telescope Compatibility: RedCat, WhiteCat, SpaceCat
- Ring/GuideScope Compatibility: WO UniGuide, Vixen Style Guide Scopes
William Optics provides quality refractors, mounts, and accessories such as eyepieces, diagonals, and mounting hardware for amateur astronomers around the world. The CEO of the company is David Yang, an avid amateur astronomer and bird-watcher who feels strongly about offering premium optics to everyone with an interest in astronomy or nature, and not just to those with plenty of cash to spare.
When William Yang was a child, he thumbed through the pages of Sky & Telescope magazine and gazed at the beautiful images of our universe laid before him. His family could not afford to buy him a telescope, but he could dream of a day when he would be able to photograph galaxies and nebulae like the astrophotographers he admired so much. In 1986, David saved up all summer to buy a telescope to watch Halley's Comet, but before that he tried his hand at building his own telescopes with whatever supplies he could find; he even "borrowed" his grandmother's eyeglasses to use as the lenses for his first refractor!
In 1996, David opened William Optics in Taiwan. Four years later, in 2000, William Optics USA began by offering their break-out 80mm Megrez refractor to consumers in the United States. The quality, as well as the price, was amazing, and before long, William Optics had positioned themselves as one of the world leaders in fast, highly portable quality refractors.
William Optics also makes some great telescope accessories. Their WO Diagonals are celebrated the world over for their machining and optical quality, and their Ultra Wide Angle (UWA) and Super Wide Angle (SWA) eyepieces, with their unusual jet-black insertion barrels, have come to be known for their quality, but at an affordable price. We think William Yang has achieved what he set out to do; providing "More Quality for Less Money"; and we look forward to what he plans to do next!