• The Coronado SolarMax III 90 Double Stack with BF15 blocking filter has the same renowned solar observation components and results as the SolarMax II, but with enhanced 2" RP dual speed 10:1 focusing and a step forward in contrast and resolution with the 90mm external H-alpha filter. This improves dark vs light contrast between Sun and background.
• Double stacked for a <0.5 Angstroms bandpass.
• Includes Coronado's patented Richfield tuning for front Etalon adjustment.
• Includes 15mm BF15 blocking filter. Other blocking filter sizes are available to be purchased separately.
• The SolarMax III 90 has a 800mm focal length and focal ratio of f/8.9.
• Thermal Stability: 0.005 Å/°C

Meade has redesigned their Coronado SolarMax telescopes. The SolarMax III series includes an improved 2" dual speed rack and pinion focuser for smoother focus control and accurate focus adjustment for both observing and imaging. The true stand out feature of the SolarMax III 90mm telescopes is their 90mm external H-Alpha filter for improved contrast and sharper features than the telescopes with smaller etalons. The result is darker backgrounds and heightened detail on the Sun's surface and more prominently visible edge details like solar flares.

The 90mm SolarMax III is an f/8.9 dedicated h-alpha solar telescope with a 90mm external etalon and enhanced RichView tuning for an increased bandpass adjustment range. This high precision form of tuning provides velvety black backgrounds, tack sharp image resolution and increased precision in tuning when compared to previous generations. This double stacked version has an <0.5 Angstroms bandpass for superior solar surface detail.

This configuration of the SolarMax III 90 Solar Telescope comes with the BF15 15mm blocking filter which is the second equation to the solar telescope. While the initial front filter has a bandpass centered on the H-Alpha line, the blocking filter further removes any other wavelengths with the exception of the H-alpha emission line so the view of the Sun is purely H-Alpha wavelengths where a majority of activity can be seen.

There are other blocking filter sizes that come with this telescope or can be purchased separately. Depending on whether the user is doing visual or imaging, the focal length of the telescope or sensor size of the camera (APS-C vs Full Frame) will depend on the proper blocking filter size that is needed.

With Coronado's patented Richfield Tuning system, the user can adjust tuning of the front etalon filter for either high contrast views such as flares, sunspots etc to a lower prominence tuning.

Standard 5 year manufacturer warranty from date of purchase.