Coronado SolarMax III 90mm f/8.8 Double-Stacked H-alpha Solar Telescope (15mm Blocking, OTA Only)

Coronado SolarMax III 90mm f/8.8 Double-Stacked H-alpha Solar Telescope (15mm Blocking, OTA Only)

Coronado SolarMax III 90mm f/8.8 Double-Stacked H-alpha Solar Telescope (15mm Blocking, OTA Only)

B&H # COSMIII90D15 MFR # 324012
New Item - Special Order

Product Highlights

  • 800mm f/8.8 Solar Viewing Refractor
  • For Prominence and Chromosphere Viewing
  • Easily Convert for Nighttime Use
  • Double-Stacked External H-Alpha Etalon
  • RichView and T-Max Etalon Tuning Systems
  • 15mm Rear Diagonal Blocking Filter
  • <0.5Å Hydrogen-Alpha Wavelength
  • 2-Speed 2" Rack-and-Pinion Focuser
  • Vixen-Style Dovetail Mounting Plate
  • Three Eyepieces, 2x Barlow, Solar Finder
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Filter Options: Double-Stacked Etalon, 15mm Blocking

Double-Stacked Etalon, 10mm Blocking

Not available with current selections

Double-Stacked Etalon, 15mm Blocking Double-Stacked Etalon, 30mm Blocking

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Single External Etalon, 10mm Blocking

Not available with current selections

Single External Etalon, 15mm Blocking

New Item - Special Order

Single External Etalon, 30mm Blocking

Special Order

Aperture: 90mm f/8.8

70mm f/5.7 ctxavqwxfvtqbyrtytvzduawx

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90mm f/8.8
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Coronado SolarMax III 90mm overview

  • 1Description

Designed with dual external 90mm solar etalon filters, the Coronado SolarMax III 90mm f/8.8 Double-Stacked H-alpha Solar Telescope builds on the success of their earlier solar scope models to provide users with a powerful optic for solar and nighttime viewing. With the primary etalons positioned externally, users can simply and easily remove the front solar and rear blocking filters to convert the SolarMax III into a competent nighttime viewing telescope—greatly increasing the scope's versatility.

Its solar filter is specifically calibrated to isolate the hydrogen-alpha wavelength with a less than 0.5Å bandpass. The SM3's two etalons reduce the bandpass to refine the observation experience to see prominences in high contrast against the black backdrop of space, while revealing surface granulation and texture that broader bandpasses are unable to resolve. Each etalon has an independent tuning system that gives users the ability to precisely and easily bring them on band to improve contrast and enhance views when atmospheric interference or Doppler-shift cause the optical system to come off band. The primary etalon comes equipped with Coronado's rotating RichView tuning system, while the T-max tilt-tuner is employed on the secondary etalon. These two tuning methods ensure that interference between the two light paths is minimized, to further improve views.

The SolarMax III benefits from a precision 2" 7:1 dual-speed rack-and-pinion system. When used as a conventional scope, larger 2" conventional eyepieces and accessories can be used, though the more common 1.25" size is compatible when using the included 1.25" reducer adapter. The more precise focuser is complemented by a rear 90° 15mm blocking filter to provide a wide field of view and allows for full-disk viewing even with higher magnification eyepieces. This secondary blocking filter is used to further isolate the H-alpha wavelength for improved contrast on surface granulation, and prominence detail. This larger blocking filter also enables the use of eyepieces with greater field-stop diameters to be used without vignetting occurring, as might occur with smaller-aperture blocking filters.

To get users started, Coronado includes a 2-to-1.25" reducer adapter and three CEMAX eyepieces that produce low, medium, and high powers, plus a 2x Barlow lens that doubles the magnification of each eyepiece. The eyepiece holder and blocking filter will accept any 2" solar eyepiece or accessory, and with the reducer adapter any 1.25" eyepiece can also be used. The optical tube assembly is offered here without a mount or tripod, but comes with a Vixen-style dovetail plate for users who already have a reliable and stable mount and support system. To protect the OTA and accessories during transport and storage, Coronado includes a hard carrying case with a custom-cut foam lining. The case is color-matched to the OTA in their elegant black and gold color scheme.

With the Coronado SolarMax III telescope you can enjoy stunning views of our closest star, and by simply removing the exterior solar filters you can view the moon, planets, and deep-sky objects at night.

Optical Tube Assembly
  • Use for daytime solar observation, or as a conventional nighttime scope with the solar and blocking filters removed
  • 90mm aperture improves contrast and solar details, and makes it ideal for lunar and planetary viewing, or to see bright deep-sky objects at night
  • Moderate f/8.8 focal ratio
  • Long 800mm focal length boosts magnification potential enabling higher powers to be used for more detailed views
  • Achromatic refractor-style lens configuration
  • Fully multi-coated optics improve light transmission, color rendition, contrast, and sharpness
  • 7:1 dual speed rack-and-pinion focuser allows for fast coarse and precise fine focusing to achieve tack-sharp images
  • 2" drawtube enables the use of larger eyepieces and accessories for full-disk viewing without vignetting
Solar Filter
  • Double-stacked 90mm aperture solar filter system reduces the bandpass for improved contrast and views
  • Fully external filters, etalons, and tuning systems allow filter to be completely removed
  • Tuned for viewing in the hydrogen-alpha wavelength, at 6562.8Å with a bandpass of less than 0.5Å
  • Reveals prominences in high contrast against the black backdrop of space
  • Observe surface granulation and texture with high contrast
  • Rear 1.25" 15mm diagonal secondary blocking filter improves contrast, and shows more space around the sun to allow for higher magnification eyepieces to be used while maintaining full solar disk viewing
  • Proprietary RichView tuning system on the primary etalon and the T-max tilt tuner on the secondary allow the etalons to be independently tuned for Doppler-shift compensation or to highlight specific zones without having the two tuned light paths interfere with each other
  • Optical tube assembly only—mount and tripod required for proper use
  • Mounting ring assembly allows the relative position of the OTA to the mount to be adjusted for proper balance and to limit obstruction with mount, counterweights, or other gear
  • Vixen-style dovetail plate available for use with conventional telescope mounts
  • Weight: 22 pounds
Included Accessories
CEMAX Eyepieces:
  • 1.25" diameter barrel
  • 25mm yields a low power of 32x
  • 18mm produces a medium magnification of 44x
  • High-power 12mm eyepiece produces 67x magnification
  • Fold-down rubber eyecup for use with or without eyewear
  • Designed specifically for use at H-alpha wavelengths to improve contrast and minimize glare
CEMAX Barlow Lens:
  • Specifically tuned to complement the eyepieces and rear blocking filter
  • Effectively doubles the magnification of any eyepiece used with it, without affecting eye relief, to make high-power viewing more comfortable
  • 1.25" nosepiece and holder
Sol Ranger Viewfinder:
  • Solar finder enables safe aiming of the OTA at the sun
Carrying Case:
  • Protects OTA and accessories during transport and storage
  • Hard aluminum exterior with reinforced corners and edges
  • Dual snap-lock latches with hinged handle
  • Custom-cut interior foam lining
  • Iconic Coronado black and gold coloring matches the optical tube assembly and accessories
  • Dimensions: 26.5x8.7x8.7"
UPC: 709942998399
In the Box
Coronado SolarMax III 90mm f/8.8 Double-Stacked H-alpha Solar Telescope (15mm Blocking, OTA Only)
  • 25mm CEMAX Eyepiece
  • CEMAX 18mm H-Alpha Solar Eyepiece (1.25")
  • CEMAX 12mm H-Alpha Solar Eyepiece (1.25")
  • CEMAX 2x Barlow Lens (1.25")
  • Sol Ranger Solar Viewfinder
  • 90° 15mm H-Alpha Blocking Filter (1.25")
  • 1.25" Eyepiece Reducer Adapter
  • Cradle Ring Assembly with Dovetail
  • Hard Carrying Case
  • Limited 5-Year Warranty
  • Table of Contents
    • 1Description

    Coronado SolarMax III 90mm specs

    Optical Tube Assembly
    Aperture 90 mm / 3.5"
    Focal Length 800 mm
    Focal Ratio f/8.8
    Eyepiece Barrel Diameter 1.25", 2"
    Finderscope Yes
    Mounting System Vixen Style
    Filtration Wavelength Hydrogen-alpha
    Bandpass <0.5 Å
    Blocking Filter 15 mm (External)
    Assembled Dimensions 31.2 x 7.0 x 6.2" / 79.2 x 17.8 x 15.7 cm
    Weight 21.6 lb / 9.8 kg

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