Coronado SolarMax III 90 3.5" F/8.9 solar telescope with 15mm blocking filter


Availability: In stock

The <0.7 Ångstrom H-Alpha solar filter of the Coronado SolarMax III 90mm solar telescope combines with unique RichView tuning and a 15mm blocking filter to provide you with high definition views, binoviews, and DSLR format imaging of solar flares, prominences, and more . . .

Our Product #: SM39015
Coronado Product #: 324013

Product Description

This Coronado SolarMax III 90 solar telescope is designed to do much more for you than merely show you sunspots, as an ordinary white light solar filter can. Its Hydrogen-Alpha solar filter reveals features of the Sun that are normally hidden by the fierce glare of this nearest of stars - features that change constantly as you watch. The high resolution 90mm aperture of the SolarMax III 90 reveals intricate and subtle details in the ever-changing tapestry of prominences leaping off the edges of the solar disk, the explosive upheavals of flares on the Sun's disk, and the subtle mottling of granulation across the face of the Sun.

The Coronado SolarMax III 90 solar telescope by Meade starts with a brass and black 800mm focal length 90mm aperture f/8.9 refractor. It has been custom-built to provide high definition Hydrogen-Alpha solar feature views using Coronado's unique RichView tuning Hydrogen-Alpha solar filter.

The two-piece solar filter consists of a front mounted etalon  and a 15mm clear aperture blocking filter in the scope's 1.25" star diagonal. The solar filter has a <0.7 Ångstrom passband, centered on the 6562.8 Ångstrom H-Alpha line. The sub-Ångstrom passband width gives you an ideal balance of prominence and surface detail alike. The filter is thermally stable, so there is no drifting off the H-Alpha line as the filter heats up during use. The 15mm blocking filter version of this scope is designed for visual observers and imagers who do not need quite as wide an illuminated field for use with medium (APS-C) chip size DSLR or CCD cameras.

The SolarMax III 90 has a  has a new two-speed rack & pinion focuser which creates a more user-friendly interaction with the telescope. The two-speed, 2” focuser has both coarse and fine focus controls allowing the user to get a more precise focus, critical for both solar imaging and visual observing. This method provides enough back focus to allow both visual observing and imaging.

A set of Coronado Cemax 1.25" eyepiece is standard equipment, providing magnifications of 32x with a 1.62° field, 44x with a 1.18° field, and 67x with a 0.78° field. You can use most 1.25" eyepieces with the Coronado SolarMax III 90, as well. Any good quality 50° field Plössls will work well, as their contrast is generally good and their fields are wide and flat. For still higher power views, consider using the included Coronado Cemax 2x Barlow with your system. Like the Cemax eyepieces, its performance and coatings are optimized for solar observing.

A hard carrying case is standard equipment to transport and store the 90mm Coronado SolarMax III. A set of mounting rings is provided to let you mount the 30" long 23 lb. SolarMax III 90 telescope on a suitably-sturdy astronomical mount by adding an optional dovetail mounting plate. The supplied Coronado Sol Ranger Sun Finder makes it easy to center the Sun's image in the eyepiece. The Sol Ranger connects to the supplied SolarMax III 90 mounting ring as can be seen in the image above.

A "double stack" version of the SolarMax III 90 is also available that adds a second tunable SolarMax III filter to the front of the scope. Double-stacking the filters improves the scope's already outstanding resolution and contrast by cutting the passband from <0.7 Ångstrom to a very narrow <0.5 Ångstrom. This improves the contrast and visibility of subtle disk features, although it slightly reduces the brightness of prominences.

Tech Details

Aperture 3.54"
Binary and Star Cluster Observation No
Focal Length 800mm
Focal Ratio f/8.9
Galaxy and Nebula Observation No
Lunar Observation No
Weight 23 lbs.
Planetary Observation No
Resolution 1.29 arc seconds
Warranty 1 year


Review by:
I have the older version of this telescope that I was able to get for $2500. The focuser and tuning are different but completely adequate. It is interesting to see prominences change in less than an hour. I am still learning how to find locations and time of day to get the best seening. Don't know how this scope compares with others on the market but I am very satisfied and happy I got the 90mm version. (Posted on 7/22/2019)
How do you rate this product? *

Supplied Accessories

  • 90mm f/8.8 optical tube, <0.7 Ångstrom SolarMax III filter, combined 30mm aperture BF30 blocking filter and 1.25" star diagonal, Cemax 1.25" eyepiece set with Barlow, lens cover, clamshell mounting ring, Sol Ranger finder, hard case.