The Coronado SolarMax III 90mm refractor is the largest aperture in the SolarMax III series of telescopes, ideal for viewing stunningly high resolution details of our nearest star. Lightweight, compact, and includes a sturdy hard shelled carrying case with foam interior — allowing you to take this hydrogen-alpha (H-α) telescope anywhere in the world with you, whether it be your own backyard or chasing down the next great solar eclipse!
Designed and Manufactured in North America. The Coronado SolarMax III 90mm lens blanks are manufactured in the USA for Meade.
The heart of the SolarMax III 90mm is the large external front 90mm air-spaced etalon which allows viewing of the most stunning part of the solar spectrum — Hydrogen-alpha light (6562.8 Angstroms), which is where many of the beautiful features of the solar disk and atmosphere radiate best. And with a bandpass of <0.7 Angstroms (Å), contrast is exceptional for seeing prominences spilling off the edge of the solar disk, as well as many surface features including sunspots, filaments, active flare regions, plages and surface granulation.
An integral part of making this system safe for solar viewing is the 15mm blocking filter (BF15), located inside the diagonal holder below the eyepiece. It consists of multiple internal filters such as the Induced Transmission Filter (ITF), Long Wave Pass filter (LWP), and H-a cut-off filter. All BF15s use a 15mm clear aperture H-a cutoff filter which provides a fully unvignetted image with the included eyepieces. Compared with the smaller BF10 on the 70mm Coronado telescopes, this BF15 provides an even larger unvignetted area — useful when viewing features with higher magnification or imaging with larger camera sensors. The BF15 will accept any 1.25" eyepiece or imaging equipment with t-thread. The SolarMax III 90 features an 800mm focal length (f/8.9) refractor doublet lens with 90mm aperture yielding a clean, high contrast image across the field of view.
Tuning the image of the sun for the best contrast is made possible with Coronado's patented RichView tuning technology, which adjusts the distance between the parallel glass plates of the external etalon in order to achieve the perfect wavelength bandpass for the feature you are observing, all while maintaining precise optical alignment. This patented technology provides additional etalon tuning range and also allows the SolarMax III to be used at high altitude observing locations. The RichView system simply allows for better control over your H-a bandpass window. In addition to RichView tuning, the included T-Max Tuner allows you to tune in the brightest image and remove any reflections from the image. Combined, the RichView and T-Max together offer unparalleled image tuning to get the best possible view of solar details!
The Sun in hydrogen-alpha light showing some of the different features visible around the solar disk.
The telescope includes a backlash free 2" dual-speed rack & pinion focuser with course and fine focus (10:1 reduction) and a Sol Ranger Solar Finder, which is a quick and easy way to aim at the sun. Optical accessories that come standard with the SolarMax III 90mm include 25mm, 18mm, and 12mm CEMAX eyepieces, and the CEMAX 2x 1.25" Barlow. Also included is a Vixen-style dovetail mounting rail and an all-new black and silver aluminum hard carry case (Dimensions: 26.5" x 8.66" x 8.66").
Coronado assures that all solar filters and solar telescopes are tested at specialized labs that are accredited to verify compliance with the ISO 12312-2 safety specifications for solar viewing.
