BST 2" Variable Transmission Polarizing Filter
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- Variable 2" polarizing filter improves subtle detail in Moon and bright planets
- Cuts down on glare from Moon and bright terrestrial images
- Transmission continuously variable from 2-40% for a wide range of viewing situations
While observing the moon or planets, there is often too much light that washes out subtle details. This glare can be cut back using neutral density filters or polarizers. The variable polarizing filter makes this even better by stacking two polarizing filters together and combining them with a special ring that prevents the two individual filters from getting separated during normal use. By rotating the two elements, light transmission can be varied between about 2% and 40%. This filter retains true color balance since all wavelengths are transmitted uniformly over the entire spectrum.
The two polarizing elements can be unscrewed to obtain two polarizing filters which can be used for day time photography or to improve contrast in images when only a little reduction in transmitted light is desired. The filter has a standard 2" thread (M48 x 0.75) so it can be screwed on to any virtually any standard 2" eyepiece or accessory.
Specifications:
- Total item length (including external male thread) = 15.8mm (0.62")
- Clear aperture = 44.8mm (1.76")
- Weight = 0.9oz.
- Protective plastic storage case: Included
- Made in China
Useful Resources
Filter Cell Specifications
D = Filter Cell Diameter = 50 mm / 1.96 in
T = Total Filter Height = 8 mm / 0.22 in
C = Filter Cell Height (Excluding Male Thread) = 5.5 mm / 0.22 in
M = Male Thread Length = 2.5 mm / 0.1 in
F = Female Thread Length = 2.6 mm / 0.1 in
S = Glass Substrate Thickness = 2.1 mm / 0.08 in
CA = Clear Aperture = 44 mm / 1.73 in
Other Information
- Country of Manufacture: China
While observing the moon or planets, there is often too much light that washes out subtle details. This glare can be cut back using neutral density filters or polarizers. The variable polarizing filter makes this even better by stacking two polarizing filters together and combining them with a special ring that prevents the two individual filters from getting separated during normal use. By rotating the two elements, light transmission can be varied between about 2% and 40%. This filter retains true color balance since all wavelengths are transmitted uniformly over the entire spectrum.
The two polarizing elements can be unscrewed to obtain two polarizing filters which can be used for day time photography or to improve contrast in images when only a little reduction in transmitted light is desired. The filter has a standard 2" thread (M48 x 0.75) so it can be screwed on to any virtually any standard 2" eyepiece or accessory.
Specifications:
- Total item length (including external male thread) = 15.8mm (0.62")
- Clear aperture = 44.8mm (1.76")
- Weight = 0.9oz.
- Protective plastic storage case: Included
- Made in China
- Variable 2" polarizing filter improves subtle detail in Moon and bright planets
- Cuts down on glare from Moon and bright terrestrial images
- Transmission continuously variable from 2-40% for a wide range of viewing situations
While observing the moon or planets, there is often too much light that washes out subtle details. This glare can be cut back using neutral density filters or polarizers. The variable polarizing filter makes this even better by stacking two polarizing filters together and combining them with a special ring that prevents the two individual filters from getting separated during normal use. By rotating the two elements, light transmission can be varied between about 2% and 40%. This filter retains true color balance since all wavelengths are transmitted uniformly over the entire spectrum.
The two polarizing elements can be unscrewed to obtain two polarizing filters which can be used for day time photography or to improve contrast in images when only a little reduction in transmitted light is desired. The filter has a standard 2" thread (M48 x 0.75) so it can be screwed on to any virtually any standard 2" eyepiece or accessory.
Specifications:
- Total item length (including external male thread) = 15.8mm (0.62")
- Clear aperture = 44.8mm (1.76")
- Weight = 0.9oz.
- Protective plastic storage case: Included
- Made in China
Useful Resources
Filter Cell Specifications
D = Filter Cell Diameter = 50 mm / 1.96 in
T = Total Filter Height = 8 mm / 0.22 in
C = Filter Cell Height (Excluding Male Thread) = 5.5 mm / 0.22 in
M = Male Thread Length = 2.5 mm / 0.1 in
F = Female Thread Length = 2.6 mm / 0.1 in
S = Glass Substrate Thickness = 2.1 mm / 0.08 in
CA = Clear Aperture = 44 mm / 1.73 in
Other Information
- Country of Manufacture: China