Filters

Based on Coronado's original AS1 series filters these two-piece filter sets represent over one hundred years of developments in the Fabroy-Peret etalon, most of which have been accomplished by the engineers at Coronado during the past ten years. The AS1 series broke down the barrier that had kept the etalon a relatively obscure filter to the amateur community

Thermal Stability
By adding a central obstruction Coronado has been able to develop a patented, thermally stable, etalon that will work in extreme colds and extreme heats, see our thermal stability specs below. While a typical cassegrain has a central obstruction of approximately 35%,- giving an area obstruction of ~12%,- that in the SolarMax filters is only 2.5% to 5.5% depending on the model. This is well within the obstruction generally considered to be completely unnoticeable to image quality, especially on a hi-resolution object like the sun. It does guarantee a thermally stable on band performance every time you set it up.

Now called the SolarMax series filters the design has been fine-tuned and is available from stock worldwide. The filters are sold in sets. The first part or objective filter is called the SolarMax and houses our patented etalon and an energy rejection filter. The second part is called the Blocking Filter or BF. The BF 5, 10, and 15 are all housed in a 1.25" diagonal and the BF30 is a straight through 2" design with reducer.You pick the objective filter that best matches your telescopes aperture and your budget. A 140mm telescope should use the SolarMax 90 but it will also work witha 40 or 60, a 50mm telescope should only use the SolarMax 40. You then choose your BF based on the focal length of the telescope, use the chart below. Once you have found the product you want click on 'In Stock' from the main drop down menu in the upper right hand side. There is no visual advantage to using a larger blocking filter than is required according to this chart.

Focal Length <500mm = BF5

Focal Length <1000mm = BF10

Focal Length <1500mm = BF15

Focal Length <3000mm = BF30

Displaying 1 to 10 (of 10 products)

Result Pages: 1

Product Name+	Manufacturer	Price
SolarMax 140 no blocking filter (Item #SM140)	Coronado	$14,999.00 Free Shipping
SolarMax40/BF10/TMax (Item #SM40/10)	Coronado	$1,450.00 Free Shipping
SolarMax40/BF15/TMax (Item #SM40/15)	Coronado	$1,725.00 Free Shipping
SolarMax40/BF5/TMax (Item #SM40/5)	Coronado	$1,099.00 Free Shipping
SolarMax60/BF10/TMax (Item #SM60/10)	Coronado	$2,590.00 In Stock Free Shipping
SolarMax60/BF15/TMax (Item #SM60/15)	Coronado	$2,865.00 Free Shipping
SolarMax60/BF30/TMax (Item #SM60/30)	Coronado	$3,590.00 Free Shipping
SolarMax90/BF10/Tmax (Item #SM90/10)	Coronado	$5,045.00 Free Shipping
SolarMax90/BF15/Tmax (Item #SM90/15)	Coronado	$5,320.00 Free Shipping
SolarMax90/BF30/Tmax (Item #SM90/30)	Coronado	$6,045.00 Free Shipping

Displaying 1 to 10 (of 10 products)

Result Pages: 1

Astronomy Picture/Day

Logarithmic Spirals

See Explanation. Clicking on the picture will download the highest resolution version available.

We carry...