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Coronado's single-etalon SolarMax II 90 90mm f/8.8 H-alpha Solar Telescope represents the largest aperture and longest focal length in the SolarMax II series. It offers the highest magnification potential and clearest views compared to smaller iterations. This scope is calibrated for the Hydrogen-alpha wavelength, and comes equipped with Coronado's RichView tuning system. This system allows direct adjustment of the primary etalon filter enabling it to be tuned up or down from the 6562.8Å wavelength for highlighting specific zones of the chromosphere and to compensate for Doppler shift that can pull prominences and other features off-band and affect views. Tuning areas of concentration back on-band allows for higher-contrast views of prominences on the solar limb.
Complementing the primary etalon filter is a rear internal 30mm blocking filter. This secondary filter further isolates the H-alpha wavelength to improve contrast and enhance views. While a smaller 10mm or 15mm blocking filter would suffice, Coronado includes this larger option to allow the use of eyepieces with larger field-stop diameters to be used without vignetting occurrences, as might be seen with smaller filters, which would interfere with the field of view. Setting this rear blocking filter internally enables the use of the included 90° star diagonal for comfortably viewing the Sun when it is high in the sky, or without the diagonal for direct-connection of imaging rigs.
The SolarMax II is offered here without a mount or tripod, but comes with a wide clamshell mounting ring that is outfitted with a 1/4"-20 socket for attachment onto many photo/video/field tripods or on piggyback rigs, or an optional Vixen-style dovetail plate is available for use with conventional alt-az, EQ, or motorized telescope mounts.
f/8.8 focal ratio
800mm focal length
Refractor-style lens configuration
Designed for viewing in the Hydrogen-alpha wavelength (6562.8Å)
Reveals prominences in high contrast; and under the right conditions, surface texture
Internal primary etalon blocking filter
Rear internal 30mm secondary blocking filter allows the use of standard 90° star diagonals for viewing, or straight-through attachment of imaging rigs
Proprietary RichView tuning system allows the internal etalon to be tuned for Doppler compensation or to highlight specific zones
Thermal Stability: 0.005Å/°C
Included Cemax Eyepiece
1.25" diameter barrel
25mm focal length yields 32x
Field of View: 52°
Fold-down rubber eyecup for use with or without eyewear
Designed specifically for use at H-alpha wavelengths
20mm eye relief
Use and Handling
1.25" diameter drawtube
90° star diagonal included. Places head in comfortable viewing position when OTA is aimed at or near the zenith
Helical focuser with easy-to-use focus collar
Sol Range solar viewfinder enables safe aiming of the OTA at the Sun
Included carrying case keeps OTA safe during transportation and storage
Mount and tripod required
Mounting ring allows the relative position of the OTA to the mount to be adjusted for comfort and limit obstruction
Clamshell mounting ring with 1/4"-20 mount for using photo/video/field tripods or piggyback rigs
Optional Vixen-style dovetail plate available for use with conventional telescope mounts
In the Box
Coronado SolarMax II 90 90mm f/8.8 H-alpha Solar Telescope (30mm Blocking, OTA Only)