William Optics

ZenithStar 103 f/6.9 Doublet APO


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  • Regular price $1,298.00


When you are looking at deep sky images on a starry night, have you ever dreamed about taking beautiful photos with clear details?  By using FPL-53 glass, the Zenithstar 103 Apo provides apochromatic grade color correction, extreme sharpness, clear details, and colorful images. 

The William Optics ZenithStar 103 features an f/6.9 FPL-53 Doublet air-spaced APO in a CNC machined ultra-high precision lens cell. With an 0.8x flattener, this can also become an f/5.5. Using the 0.8x field flattener, the image circle is up to full frame, and the focal length is 560mm at f/5.5, perfect for imaging deep sky objects.  

The ZenithStar 103 APO is available in three colors: Gold, Blue, and Red. It has an innovative Bahtinov Mask Cover (Patented) included!

Comes with a 2.5-inch rack-and-pinion ultra-robust focuser with 10:1 dual speed.

Thanks to its design, there is NO image shifting, making this a real treat to use in astrophotography!

Despite its 103mm objective, the scope is still very compact and solid. Many airlines will accept it as carry-on luggage! It's the perfect size for serious observations of deep sky objects and planets. Solar observations are possible with proper additional equipment.

Standard Package:

  • Mounting Rings
  • CNC Carry Handle Bar with slide base for guide scope
  • Long Vixen Style Dovetail Plate
  • 2.5-inch Rack-and-Pinion Focuser
  • Innovative Bahtinov Mask Cover (Patented)
  • Two-year, no fuss warranty and constant customer service!
Aperture 103 mm (4")
Camera/Eyepiece Connection 1.25", 2" Nosepiece, or Dedicated Flattener 
Dawes Limit 1.13 arcseconds
Focal Length 710 mm
Focal Ratio f/6.9
Glass Type FPL-53
Highest Magnification 206x
Light Gathering Power 217x
Limiting Magnitude 13.8
Optical Design Doublet
Tube Diameter 112mm
Tube Length 615mm
Tube Weight 9.61 lbs
SKU: A-Z103IIRD
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