Coronado SolarMax II 40mm H-Alpha Filter w/ BF5

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Coronado SolarMax II 40mm H-Alpha Filter w/ BF5   Discontinued
Item # CI-SMF40-5
  • The Coronado SolarMax 40 System is a 40mm <0.7A AS1-Series thermally stable H-Alpha solar filter.
  • This package includes a BF5 interference filter (5mm 1.25" right angle diagonal blocking filter), 40mm front narrowband filter and a RichView tuner.
  • The Coronado SolarMax 40 System is optimized to provide a full disc image on telescopes with a focal length of up to 500mm.


Coronado SolarMax II 40mm Filter with 5mm Blocking Filter and RichView Tuner

The Coronado SolarMax 40 h-alpha solar viewing system offers an incredible opportunity for the amateur to enter the world of H-Alpha observing at a relatively low price. This particular SolarMax (other sizes are available) is a 40mm AS1-series, thermally-stable H-Alpha filter with a wavelength of 6562.8A and a bandwidth of <0.7A. It is ideal for use with a short, fast refractor and is mounted to the front of the telescope with a Coronado Instruments adapter plate, which is sold separately.

The Coronado Instruments SolarMax series filters come in two parts, the front narrowband element as listed above and a secondary interference filter which mounts at the eyepiece end of the telescope. You cannot use the individual units separately. The blocking filter you should use depends on the focal length of your telescope.

A BF5 is included with this filter. The BF5 is a 5mm blocking filter that is mounted inside the body of a 1-1/4" right-angle diagonal. It is optimized to provide a full disc image on telescopes with a focal length of up to 500mm. Note: If you have a telescope with a focal length of less than 1000mm, you will want to purchase the Coronado SolarMax 40 with the BF10 Blocking Filter.

About the RichView Tuner...

Some events on the Sun, notably active flares and coronal mass ejections (CME's) are extremely fast moving. If such features occur on the disc of the Sun, their high velocity towards the observer results in their wavelength being Doppler-shifted shorter than Ha. If the velocity is high enough, this wavelength could be outside the passband of the filter and the feature would not be observable. The RichView allows the user to de-tune the SolarMax slightly to bring such phenomena into better visibility. The RichView fits between the Coronado SolarMax and it's adapter plate. A simple rotary wheel movement accomplishes the tilt necessary to move the passband of the filter. Because of the filter's position at the front end of the telescope, this does not compromise the performance of the filter nor limit the Ha field of view as is the case with rear-mounted filters.

Below you'll find a list of explanations regarding important accessories that may be required for this product.

  • You will need an Adapter Plate to attach the Solarmax to your telescope. If you do not find your telescope listed among our choices, don't despair! Just contact our Internet Sales Department by email or by phone at 1-800-483-6287 and tell us what telescope you have. 99% of the time, we'll be able to get you the appropriate plate.

Important Note: OPT highly recommends a 2nd Day Air shipping upgrade on this product. Please read Coronado's new Shipping Policy (PDF, 60K) for important information regarding this recommendation...your choice could affect the manufacturer's warranty!

Coronado Instruments Product Number: SMF40-5

Additional Information

Additional Information

UPC Code 709942996401
Aperture 40mm
Emission Line H-Alpha
Bandwidth <0.7A
Blocking Filter Included BF5
Best for Focal Lengths of... f/30 or Under
Blocking Filter Barrel Size 1.25"
Manufacturer Coronado
Warranty 1 Year Warranty
Wavelength <0.7 A
Included Items

Included Items

  • SolarMax 40 <0.7A H-Alpha Filter
  • BF5
  • RichView Tuner
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