Coronado SolarMax II 90 <0.5A H-Alpha Telescope with BF30, Internal & External Etalon

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Coronado SolarMax II 90 <0.5A H-Alpha Telescope with BF30, Internal & External Etalon

Regular Price: $6,799.00

Special Price $5,779.00

Item # CI-SMT90DS-30
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Limited Time: Stellar Solar Savings!
  • The largest H-A telescope ever to be mass-produced and is in use around the world from private observatories to professional research facilities.
  • The Coronado SolarMax II 90 has a sub-ngstrom passband width gives you an ideal balance of prominence and surface detail.
  • Utilizes an internal and external etalon to achieve the bandwidth of <.5A. The telescope cannot be used without the external etalon filter in place.
  • The Coronado SolarMax II 90 package includes Cemax eyepiece set, hard travel case, Sol Ranger, clamshell rings and 5 year warranty.


Coronado SolarMax II 90 <0.5A

Coronado has developed a series of telescopes as a result of the often asked question, "What is the best telescope to use with a Coronado filter?" While almost all refractors and most reflecting telescopes can be used with a Coronado filter, no other telescope has been designed with all its optical aberrations and coatings optimised at H-Alpha. Most nighttime telescopes, when used at H-alpha, will not have the image contrast exhibited by a SolarMax II nor the image quality. Most broadband coatings, used on such telescopes, will have reduced effectiveness at this wavelength and telescopesYear Coronado Warranty. (particularly reflectors) not specifically designed for Solar viewing, will exhibit unnecessary scattering and spurious light transmission. All of the Coronado scopes, even the PST, have been designed with this one wavelength of light in mind and will increase contrast and give you a darker background for viewing and imaging.

"Why buy a telescope that can only look at one object?" The Sun in H-A is the most dynamic object you will ever see while pointing a telescope skywards. Constantly changing and never repeating itself the Sun through a Coronado filter will hold your attention for a lifetime. Coronado telescopes serve to enhance that view for you, your family, and friends. The telescopes provide an easy and portable set up that is always ready right out of the box. For those looking for more aperture we proudly present the SolarMax 60 dedicated H-alpha telescope. Built to our exacting standards the SolarMax II 90's provides the user a telescope with the same lightweight portability of our SolarMax 60 but the extra aperture greatly increases the resolution of detail on the surface and on the limb. With over twice the surface area of the SolarMax II 60 the difference is obvious.

The SolarMax II 90 is the largest H-A telescope ever to be mass-produced and is in use around the world from private observatories to professional research facilities. Noted for incredibly sharp, ‘contrasty’ H-Alpha views, and stunning detail. Even when viewing with a single eyepiece the sun appears fully animated even revealing hints of curvature, this effect is enhanced when used with bino-viewers. The SolarMax 90 is compatible with most imaging systems and amateur astronomers have produced images that rival those gathered by multi million dollar systems.

This Coronado SolarMax II 90 is a handsome aluminum and black f/8.8 refractor with 800mm focal length and 90mm aperture. Its purpose is simple. The Coronado SolarMax 90 <0.5A was custom-built to optimize the performance of the SolarMax 90 Hydrogen-Alpha solar filter. The SolarMax 90 was intended to do much than just reveal sunspots... it was meant for studying prominences, flares, granulation and more. The achromatic doublet lens designed by Dick Buchroeder utilizes special multi-layer antireflection coatings on all air-glass surfaces to optimize anti-ghosting. This is an important feature when observing such a bright target as the Sun. Safety issues include hard vacuum-deposited. non-degenerating coatings. This means not only are you assured your vision is protected but your investment as well. The Coronado SolarMax 90, when properly cared for, will last a lifetime.

The dual etalons of the Coronado SolarMax 90 are used to sharpen the filter's normal <0.7 Ångstrom passband to a very narrow <0.5 Ångstrom centered on the 6562.8 Ångstrom H-Alpha line, thus improving contrast over the single etalon version. A complete second 90mm etalon assembly is mounted in front of the Coronado SolarMax 90's normal full-aperture 90mm etalon along witha factory-installed and performance-matched second etalon mounted inside the telescope barrel. This etalon combination provides the contrast benefits of double stacking, but offers it at a lower cost. By using factory-matched etalons, you are also added better performance than an additonal etalon added at a later time. .

On the outside, the Coronado Solar Max 90 <0.5A consists of a manual 1.25" drawtube which extends for coarse focusing. A secondary helical focusing ring around the drawtube is then used to provide the appropriate final fine focusing. Both visual observing and afocal imaging, as well as barlow lenses are able to come to focus using this method and digital photography and binoviewers also experience no problems with focus. Between the the solar filter etalon and the objective lens you'll find the RichView tuner which mechanically tilts the filter's bandpass of the h-alpha line. This allows observance of Doppler-shifted solar activity, such as moving flares!

Coronado SolarMax 90 <0.5A Features...

  • Cemax Eyepiece Set and Cemax Barlow Included!
  • Threaded, Protective Metal Cover For Primary Lens.
  • SolRanger Sun Finder.
  • Deluxe Hard Carrying Case.
  • Clamshell Mounting Rings w/1/4"-20 Thread Tripod Adapter.
  • Solar Max 90 Is "Double Stacked"!
Coronado Instruments Product Number: SMT90DS-30
Additional Information

Additional Information

UPC Code 709942996333
Solar Instrument Type Telescope
Aperture 81mm - 99mm
Emission Line H-Alpha
Manufacturer Coronado
Warranty 1 Year Warranty
Blocking or ERF Aperture 30mm
Bandwidth <0.5 A
Telescope Focal Length 800mm
Telescope Focal Ratio f/8.8
Solar Finder Included? Yes
Tuner Included? Yes
Length of Optical Tube 30"
Optical Tube Weight 23 lbs.
Included Items

Included Items

  • SolarMax II 90 <0.5A with Internal & External Etalon
  • BF30
  • RichView Etalon Tuning System
  • Sol Ranger
  • Clamshell Mounting Rings
  • Hard Travel Case
  • Full CEMAX Eyepiece Set
  • Manufacturer's Five Year Limited Warranty
Questions & Answers

Product Questions

What is the practical difference between the BF30 and BF15?
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