Intes MN61 6″ f/6 Maksutov-Newtonian

The Intes MN61 MAKSUTOV-NEWTONIAN (MAK-NEWT) is product design from INTES+ of Moscow, Russia. The revolutionary design combines the best features of the Newtonian (simplicity of the optics) with the Maksutov (highly corrected optics) in an affordable package. Because of the closed tube design and the lack of any secondary support spiders, only 19.7% (by diameter) of the aperture is blocked by a central obstruction. This, combined with the extremely high quality of the optics (minimum of at least 1/6 wave p.t.v. or better for the whole system), results in very high contrast, bright images similar to those expected in a very good 130 to 150mm Apochromatic Refractor.

Intes MN61 Review

Intes MN61

Many amateur astronomers are already familiar with this telescope design from the inroads made by the famous optician in Canada, Peter Ceravolo, with his HD 145 (145mm f/6 Maksutov-Newtonian). Ceravalo was the first person to commercialize the design and to convince experienced amateur astronomers of its unique merits. However, until INTES introduced the MN61, most amateur astronomers did not consider a Mak-Newt affordable. The MN61 has changed the “ball game” forever and for the better.

This is a true “diffraction-limited” optic that will outperform many more astronomical aperture telescopes on the planets, double stars, galaxies and nebulas. The OTA is made of aluminum with a semi-permanent dew shield (removable with six screws) and a floating cell for the primary mirror. Focusing is afforded either by a 2″ Crayford focuser or by a very smooth 2-inch ultra-low-profile helical focuser within integral draw tube (select either one at the time of purchase). The standard offering also includes a beautiful set of tube-rings and a mounting plate. The field of view with a 35 mm Tele Vue Panoptic eyepiece is about 3 degrees so that objects like the North American Nebula are fully visible. The fast f/6 focal ratio of the INTES MN 61 also makes it an unexcelled astrograph for CCD imaging.

We have found that no other telescope can show as much planetary detail per inch of aperture than this instrument. The INTES MN 61 was recently tested side-by-side against a Zeiss 130 mm APO and an APM-Telescopes 150 mm APO Fluorite Refractor on the planet Jupiter. The INTES MN 61 easily outperformed the Zeiss 130mm APO Refractor and showed nearly the same planetary details like the high-end 150mm APO Fluorite Refractor. This optic also provides stunning views of deep space objects, including some of the more difficult faint or diffuse nebulas. Other similar testimonials have been widely circulated on the Internet. In summary, images in the MN-61 are equal to those in the same aperture APO refractor at the same focal ratio!

There are two versions of the MN61 available: The Standard and the Deluxe. The Deluxe version has an optical quality of 1/7 wave p.t.v. or better and Astral Sital mirrors with 96-98% reflective coatings.

Intes MN61 Specifications

  • Clear Aperature: 6″ (152 mm)
  • Focal Length: 900mm
  • Focal Ratio: f/6
  • Diameter of the Secondary: 30mm
  • Central Obstruction (by diameter): 19.7
  • Tube Length including Dewcap: 950mm
  • Tube Diameter: 178mm
  • Tube Weight: 9.5 kg (19.5 pounds)
  • Tube Material: Aluminum
  • OTA Color: Grey-white or jet black
  • Finder: 10x50mm (7-degree field of view)
  • Focuser: 2″ Crayford or ULP Helical
  • Primary and Secondary Mirrors: LK-5 glass, Al+SiO2 coated
  • Meniscus Lens: First Class K-8, Multi-coated anti-reflection layers
  • Optical Quality: About 1/6 wave p.t.v. or better for the system


Adjustable secondary and primary cells. Intes MN61-Standard Version, Catalog Number: 1-02-06-13 ITE Price: $1,239.00 + $35 s&h.

INTES MN61-DX, Deluxe Version, Catalog Number: 1-02-06-2 ITE Price: $1,389.00 + $35 s&h. Delivery: INTES standard manufacturing and delivery cycle comprises 2 to 3 months from the date of the receipt of the order. Therefore, it is advisable to order goods well in advance. A 50% deposit (check or credit card) will confirm an order. Persons confirming an order with 100% prepayment by check or money order will receive a 5% discount off of the listed price of the MN61.

Options and recommended accessories:
  • Cheshire Collimating Eyepiece (recommended for collimation of the telescope): $45.00
  • Soft transport case (click here for image): $150.00 + $15 s&h
  • Transport handle (click here for an image): $50 + $10 s&h
  • Losmandy GM8 Mount with dual axis drives $1,395 + $50 s&h (see the mounts page for details)
  • Losmandy Universal Dovetail Plate (to attach a scope to mount): $100.00
  • An optical evaluation test report is available for this telescope.

This telescope was reviewed April 1999 issue of Sky & Telescope (S&T). Click here for INTES’ response to several design issues raised in the S&T review article.


Effective immediately, all INTES and INTES MICRO telescopes sold by ITE in the USA will include a full ten year written warranty (1 year on optical coatings). This is keyed to the serial number of the telescope, an optical test report that certifies in writing the actual optical quality of the instrument, a complete owner manual with collimating instructions and unlimited customer service after the sale, all AT NO ADDITIONAL COST!

ITE and ONLY ITE offer you these unique value-added items. All the more reason to purchase your INTES or INTES MICRO product from ITE. IMPORTANT FOOTNOTE REGARDING OPTICAL TESTING: While others may claim to test the optics in these scopes before shipping to customers, only ITE tests the optics under controlled conditions in a fully equipped optical laboratory using calibrated instruments certified by the National Bureau of Standards and the USAF.

Tests conducted by ITE are not just subjective star tests under uncontrolled conditions (such results are highly dependent on seeing conditions and are subject to human error and observer bias). Our objective criteria include optical quality measurements in terms of wavefront error (p.t.v.), Strehl ratio, on- and -off-axis resolution and image spot size in microns. All results are published on a certified test report that accompanies the optic. Accept no substitutes for controlled objective testing of optics.

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