High Point #25 Red Filter - 1.25"
This #25 Red Filter, 14% transmission by High Point Scientific is an invaluable aid to lunar and planetary observing. Colored filters reduce light scattering and glare while increasing contrast via selective filtration. Filters also provide increased definition, reduced irradiation, and lessen eye fatigue.The red Filter has a Wratten number of #25 and can enhance views of bluish clouds on Jupiter and Saturn. With a transmission of just 14%, this red filter is perfect for daytime observations of Venus and Mercury by darkening the blue sky. Mars will also benefit from a red filter by sharpening views of the polar ice caps and yellow dust clouds.
All of High Point's colored filters are made of high quality, solid plane parallel glass that has been anti-reflection coated to prevent glare and ghosting. They have a full 26mm clear aperture and are mounted in a black anodized aluminum cell that is threaded on both sides to fit most 1.25" eyepieces and stack with each other.
Please note that 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.
1.25" #25 Red Filter
Dimensions & Specifications
Model Number: 25F1
Filter - Single or Set: Single Filter
Filter Size 31.75 mm (1.25")
Filter Type: Planetary Color
Filter Shape: Round
Mounted or Unmounted: Mounted
Wratten Number or Equivalent: #25 Red
Filter Warranty: Two Years
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