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Apertura #80A Medium Blue Filter - 1.25" - A-80AF1


Apertura #80A Medium Blue Filter - 1.25"

This Colored Filter from Apertura has a Wratten number of #80A, which is Medium Blue with a transmission of 30%. A blue filter is useful for observing the Great Red Spot on Jupiter or enhancing the boundaries between the giant planet's reddish belts and their adjacent bright zones.

A blue filter can also be used to study the surface features and polar ice caps on Mars. Or, when observing Mercury, it can be used to study the surface markings at twilight, when the elusive planet is low on the horizon. If you would like to observe Saturn, this blue filter will enhance low-contrast features, such as those found between the belts and zones. Checking out a comet? Use a blue filter to bring out definition in its gaseous tail. Colored filters can be an invaluable aid in lunar and planetary observing. They reduce glare and light scattering, increase contrast through selective filtration, increase definition and resolution, reduce irradiation and lessen eye fatigue.

Apertura's colored filters are made of high quality, solid plane parallel glass which has been anti-reflection coated, so, it prevents glare and ghosting. This blue filter has a 26mm clear aperture, and is mounted in an aluminum cell, black anodized, that is threaded on both sides. This means that it will fit most eyepieces and stack with each other.

Please Note : The effectiveness of this filter depends on several factors, including the aperture and focal length of your telescope, the magnification being used, and the seeing conditions at the time. Remember that filters lower the amount of light that reaches your eye. You'll need an aperture of at least 8 inches for dark filters such as the #47 Violet, with only 3% transmission, the #25 Red with just 14% transmission, or the #38A Blue with 17% transmission.

This Product Comes with the Apertura Absolute Warranty!

  • Two-Year Warranty against product defects.
  • Three-Year Accident Replacement Program that begins after your initial 2 year warranty expires.
  • Your Apertura Absolute Warranty is transferable.

Download a copy of the Apertura Absolute Warranty for more information on this program, how to make a claim, and why it is important to keep your original receipt and the product's original boxes & packaging!