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Optiques Fullum Folded Newtonian 40" f/3.5

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Original price $165,000.00
Original price $165,000.00 - Original price $165,000.00
Original price $165,000.00
Current price $132,000.00
$132,000.00 - $132,000.00
Current price $132,000.00

Lead-time: TBA

Ships To: United States & Canada 🇺🇸 🇨🇦

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Shipping & Returns

We offer free U.S. shipping to the lower 48 States - on most orders over $150 USD. Some limitations may apply.

Shipping fees will apply on most orders shipping across Canada, with some exceptions.

We offer a 30 Day Return Policy on most of the products that we carry.

For full details on our Shipping & Returns Policy, please click here.


The vast majority of products that we sell, with a few exceptions, are covered under Warranty.

To view the Warranty details for each brand that we sell, including products that do not qualify for Warranty, please visit here.

NOTE: These Telescopes are custom-made systems. Please contact us to discuss your specific requirements at, or feel free to call us during our posted business hours at 1-800-860-3429. The final price can vary depending on your custom requirements. The price does not include crating and shipping.

Fullum-folded Newtonian®: For large telescopes of 30 inches and more, Optiques Fullum developed a unique “Fullum-folded Newtonian” structure.  In this configuration, a parabolic primary mirror with a very short focal (F/3.5-F/4) is coupled to a secondary mirror placed much lower than normal, which will redirect the optical axis at a 17.5-degree angle instead of 45 degrees.  This results in a more secure focal spot for the observer.

  • For example, a 50-inch F/3.5 telescope ocular support would normally be made at a height of 18 feet.  By using the unique “Fullum Folded” structure, the ocular support will be at a height of only 8.5 feet.

The Fullum 40-inch Folded Newtonian will open vistas of deep sky objects to you that are impossible for telescopes of smaller aperture to achieve. Features normally invisible in bright and dark nebular structure can be endlessly explored. Under dark skies, the colors of the Orion Nebula are easily detected. 

Upon ordering, we can adjust the focal length of the primary mirror to best suit your needs (both for your physical height to the eyepiece and/or desired image scale), but at f3.5, the focal length is 3556 mm. When used with the Explore Scientific 30mm 100° Series eyepiece, it yields 118.5X with a true field of view of a little over 48 arc minutes (easily fitting in the full moon) with ample eye relief.


  • Optical design: Newtonian reflector
  • Objective diameter: 1016 mm
  • Focal length: 3556 mm
  • Focal ratio: f/3.5
  • Resolving power: 0.11 arc second
  • Stellar limiting magnitude: 17.73
  • Max. magnification: 2540 x (theoretical)
  • Light gathering power: 21,066 times the human eye


In the following video, Normand Fullum describes how he developed, and produces, his lightweight Techno-Fusion primary mirrors for the Fullum Folded Newtonian telescopes:

 In the following video, the RASC (Royal Astronomical Society of Canada) gets a tour of Normand Fullum's workshop:

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