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Showing 1–12 of 93 results
  • 49.7 mm dia. Unmounted Astrodon Johnson/Cousins Ic edge-blackened- Ic*_50R-200039 (2nd Quality Discount)

    $500.00 $446.00

    This individually serialized filter, Ic*_50R-200039, has been scored at 9.975 and has a 10.63% discount. Astrodon 2nd Quality filters are still covered by our warranty for longevity, but are otherwise sold “as is” and are not returnable.

    Astrodon 2nd Quality Filters are sold at a discount. 2nd Quality Filters are individually evaluated and graded for edge chips, scratches, pinholes and inclusions according to the standards set below:

    Edge Chips: Score 1 point for each edge chip. Score 1 additional point for each edge chip that extends into the filter more than 2mm from the edge.

    Pin holes: Score 1 point for each pinhole. Score an additional point for each pinhole that is “large”.

    Scratches: Score 1/2 point for each scratch.

    Inclusions: Score 1/2 point for each inclusion.

    Subtract the sum of the points from 100 and divide by 10. This is the filter score.

     

    Add to cart
  • 49.7 mm dia. Unmounted Astrodon Johnson/Cousins Ic edge-blackened- Ic*_50R-200040 (2nd Quality Discount)

    $500.00 $443.00

    This individually serialized filter, Ic*_50R-200040, has been scored at 9.95 and has a 11.25% discount. Astrodon 2nd Quality filters are still covered by our warranty for longevity, but are otherwise sold “as is” and are not returnable.

    Astrodon 2nd Quality Filters are sold at a discount. 2nd Quality Filters are individually evaluated and graded for edge chips, scratches, pinholes and inclusions according to the standards set below:

    Edge Chips: Score 1 point for each edge chip. Score 1 additional point for each edge chip that extends into the filter more than 2mm from the edge.

    Pin holes: Score 1 point for each pinhole. Score an additional point for each pinhole that is “large”.

    Scratches: Score 1/2 point for each scratch.

    Inclusions: Score 1/2 point for each inclusion.

    Subtract the sum of the points from 100 and divide by 10. This is the filter score.

     

    Add to cart
  • 49.7 x 49.7 mm square Unmounted Astrodon Johnson/Cousins UV edge-blackened-UV*_50S-200041 (2nd Quality Discount)

    $550.00 $481.00

    This individually serialized filter, UV*_50S-200041, has been scored at 9.9 and has a 12.50% discount. Astrodon 2nd Quality filters are still covered by our warranty for longevity, but are otherwise sold “as is” and are not returnable.

    Astrodon 2nd Quality Filters are sold at a discount. 2nd Quality Filters are individually evaluated and graded for edge chips, scratches, pinholes and inclusions according to the standards set below:

    Edge Chips: Score 1 point for each edge chip. Score 1 additional point for each edge chip that extends into the filter more than 2mm from the edge.

    Pin holes: Score 1 point for each pinhole. Score an additional point for each pinhole that is “large”.

    Scratches: Score 1/2 point for each scratch.

    Inclusions: Score 1/2 point for each inclusion.

    Subtract the sum of the points from 100 and divide by 10. This is the filter score.

    Add to cart
  • 49.7 x 49.7 mm square Unmounted Astrodon Johnson/Cousins V edge-blackened V*_50S-200045 (2nd Quality Discount)

    $550.00 $491.00

    This individually serialized filter, V*_50S-200045, has been scored at 9.975 and has a 10.63% discount. Astrodon 2nd Quality filters are still covered by our warranty for longevity, but are otherwise sold “as is” and are not returnable.

    Astrodon 2nd Quality Filters are sold at a discount. 2nd Quality Filters are individually evaluated and graded for edge chips, scratches, pinholes and inclusions according to the standards set below:

    Edge Chips: Score 1 point for each edge chip. Score 1 additional point for each edge chip that extends into the filter more than 2mm from the edge.

    Pin holes: Score 1 point for each pinhole. Score an additional point for each pinhole that is “large”.

    Scratches: Score 1/2 point for each scratch.

    Inclusions: Score 1/2 point for each inclusion.

    Subtract the sum of the points from 100 and divide by 10. This is the filter score.

    Add to cart
  • 49.7 x 49.7 mm square Unmounted Astrodon Johnson/Cousins V edge-blackened V*_50S-200046 (2nd Quality Discount)

    $550.00 $491.00

    This individually serialized filter, V*_50S-200046, has been scored at 9.975 and has a 10.63% discount. Astrodon 2nd Quality filters are still covered by our warranty for longevity, but are otherwise sold “as is” and are not returnable.

    Astrodon 2nd Quality Filters are sold at a discount. 2nd Quality Filters are individually evaluated and graded for edge chips, scratches, pinholes and inclusions according to the standards set below:

    Edge Chips: Score 1 point for each edge chip. Score 1 additional point for each edge chip that extends into the filter more than 2mm from the edge.

    Pin holes: Score 1 point for each pinhole. Score an additional point for each pinhole that is “large”.

    Scratches: Score 1/2 point for each scratch.

    Inclusions: Score 1/2 point for each inclusion.

    Subtract the sum of the points from 100 and divide by 10. This is the filter score.

    Add to cart
  • 49.7 x 49.7 mm square Unmounted Astrodon Johnson/Cousins V edge-blackened V*_50S-200047 (2nd Quality Discount)

    $550.00 $484.00

    This individually serialized filter, V*_50S-200047, has been scored at 9.975 and has a 11.88% discount. Astrodon 2nd Quality filters are still covered by our warranty for longevity, but are otherwise sold “as is” and are not returnable.

    Astrodon 2nd Quality Filters are sold at a discount. 2nd Quality Filters are individually evaluated and graded for edge chips, scratches, pinholes and inclusions according to the standards set below:

    Edge Chips: Score 1 point for each edge chip. Score 1 additional point for each edge chip that extends into the filter more than 2mm from the edge.

    Pin holes: Score 1 point for each pinhole. Score an additional point for each pinhole that is “large”.

    Scratches: Score 1/2 point for each scratch.

    Inclusions: Score 1/2 point for each inclusion.

    Subtract the sum of the points from 100 and divide by 10. This is the filter score.

    Add to cart
  • 49.7 x 49.7 mm Unmounted Astrodon Johnson/Cousins Ic edge-blackened- Ic*_50S-200042 (2nd Quality Discount)

    $550.00 $491.00

    This individually serialized filter, Ic*_50S-200042, has been scored at 9.975 and has a 10.63% discount. Astrodon 2nd Quality filters are still covered by our warranty for longevity, but are otherwise sold “as is” and are not returnable.

    Astrodon 2nd Quality Filters are sold at a discount. 2nd Quality Filters are individually evaluated and graded for edge chips, scratches, pinholes and inclusions according to the standards set below:

    Edge Chips: Score 1 point for each edge chip. Score 1 additional point for each edge chip that extends into the filter more than 2mm from the edge.

    Pin holes: Score 1 point for each pinhole. Score an additional point for each pinhole that is “large”.

    Scratches: Score 1/2 point for each scratch.

    Inclusions: Score 1/2 point for each inclusion.

    Subtract the sum of the points from 100 and divide by 10. This is the filter score.

     

    Add to cart
  • 49.7 x 49.7 mm Unmounted Astrodon Johnson/Cousins Ic edge-blackened- Ic*_50S-200043 (2nd Quality Discount)

    $550.00 $481.00

    This individually serialized filter, Ic*_50S-200043, has been scored at 9.9 and has a 12.50% discount. Astrodon 2nd Quality filters are still covered by our warranty for longevity, but are otherwise sold “as is” and are not returnable.

    Astrodon 2nd Quality Filters are sold at a discount. 2nd Quality Filters are individually evaluated and graded for edge chips, scratches, pinholes and inclusions according to the standards set below:

    Edge Chips: Score 1 point for each edge chip. Score 1 additional point for each edge chip that extends into the filter more than 2mm from the edge.

    Pin holes: Score 1 point for each pinhole. Score an additional point for each pinhole that is “large”.

    Scratches: Score 1/2 point for each scratch.

    Inclusions: Score 1/2 point for each inclusion.

    Subtract the sum of the points from 100 and divide by 10. This is the filter score.

     

    Add to cart
  • 49.7 x 49.7 mm Unmounted Astrodon Johnson/Cousins Ic edge-blackened- Ic*_50S-200044 (2nd Quality Discount)

    $550.00 $481.00

    This individually serialized filter, Ic*_50S-200044, has been scored at 9.9 and has a 12.50% discount. Astrodon 2nd Quality filters are still covered by our warranty for longevity, but are otherwise sold “as is” and are not returnable.

    Astrodon 2nd Quality Filters are sold at a discount. 2nd Quality Filters are individually evaluated and graded for edge chips, scratches, pinholes and inclusions according to the standards set below:

    Edge Chips: Score 1 point for each edge chip. Score 1 additional point for each edge chip that extends into the filter more than 2mm from the edge.

    Pin holes: Score 1 point for each pinhole. Score an additional point for each pinhole that is “large”.

    Scratches: Score 1/2 point for each scratch.

    Inclusions: Score 1/2 point for each inclusion.

    Subtract the sum of the points from 100 and divide by 10. This is the filter score.

     

    Add to cart
  • Astrodon 1.25″ Round 5nm Red Continuum Narrowband Filter, RedCon5_27R-200051 (2nd Quality Discount)

    $380.00 $332.00

    This individually serialized filter, RedCon5_27R-200051, has been scored at 9.9 and has a 12.5% discount. Astrodon 2nd Quality filters are still covered by our warranty for longevity, but are otherwise sold “as is” and are not returnable.

    Astrodon 2nd Quality Filters are sold at a discount. 2nd Quality Filters are individually evaluated and graded for edge chips, scratches, pinholes and inclusions according to the standards set below:

    Edge Chips: Score 1 point for each edge chip. Score 1 additional point for each edge chip that extends into the filter more than 2mm from the edge.

    Pin holes: Score 1 point for each pinhole. Score an additional point for each pinhole that is “large”.

    Scratches: Score 1/2 point for each scratch.

    Inclusions: Score 1/2 point for each inclusion.

    Subtract the sum of the points from 100 and divide by 10. This is the filter score.

     

    Add to cart
  • Astrodon 3 nm Narrowband Filter, 36mm Round – OIII3_36R-2000160 (2nd Quality Discount)

    $748.00 $635.00

    This individually serialized filter, OIII3_36R-2000160, has been scored at 9.8 and has a 15% discount. Astrodon 2nd Quality filters are still covered by our warranty for longevity, but are otherwise sold “as is” and are not returnable.

    Astrodon 2nd Quality Filters are sold at a discount. 2nd Quality Filters are individually evaluated and graded for edge chips, scratches, pinholes and inclusions according to the standards set below:

    Edge Chips: Score 1 point for each edge chip. Score 1 additional point for each edge chip that extends into the filter more than 2mm from the edge.

    Pin holes: Score 1 point for each pinhole. Score an additional point for each pinhole that is “large”.

    Scratches: Score 1/2 point for each scratch.

    Inclusions: Score 1/2 point for each inclusion.

    Subtract the sum of the points from 100 and divide by 10. This is the filter score.

    Bring Out The Faint Structures In Nebulae
    Astrodon Narrowband filters set a new bar of performance and durability for imaging and research. We offer 5 nm and ultra-narrow 3 nm bandwidths.

    Astrodon OIII filters have a center bandwidth of 500.1 nm.

     

    Read more
  • Astrodon 3 nm Narrowband Filter, 36mm, SII3_36R-2000151 (2nd Quality Discount)

    $748.00 $635.00

    This individually serialized filter, SII3_36R-2000151, has been scored at 9.8 and has a 15% discount. Astrodon 2nd Quality filters are still covered by our warranty for longevity, but are otherwise sold “as is” and are not returnable.

    Astrodon 2nd Quality Filters are sold at a discount. 2nd Quality Filters are individually evaluated and graded for edge chips, scratches, pinholes and inclusions according to the standards set below:

    Edge Chips: Score 1 point for each edge chip. Score 1 additional point for each edge chip that extends into the filter more than 2mm from the edge.

    Pin holes: Score 1 point for each pinhole. Score an additional point for each pinhole that is “large”.

    Scratches: Score 1/2 point for each scratch.

    Inclusions: Score 1/2 point for each inclusion.

    Subtract the sum of the points from 100 and divide by 10. This is the filter score.

    If you want the look of Hubble Space Telescope (HST) images, such as the famous “Pillars of Creation” (the Eagle Nebula, Messier 16), then the next filter to consider adding to your collection after H-a and OIII is the SII (es-two) or sulfur filter. The SII filter, like H-a, is a deep red filter near 672 nm. H-a, OIII and SII filters provide that Hubble look for many emission nebula. Again, tri-color narrowband imaging with these three filters can be done with the moon up, so your equipment is not sitting dormant for several weeks.

    Astrodon SII filters have a center bandwidth of 671.6nm

     

     

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