Sightron Japan Dual BP Filter (Dual Bandpass Filter) 48mm

A dual-bandpass filter is an interference filter that transmits wavelengths around the two main emission lines (Hα and OIII) emitted by celestial objects, while cutting out other wavelengths. Because it cuts out wavelengths outside of the two emission lines, it provides a powerful light pollution reduction effect, which is useful for high-contrast nebula photography such as narrowband imaging. ● Dual emission line transmission type It transmits wavelengths mainly around the two main emission lines (Hα and OIII) emitted by celestial objects, and cuts out other wavelengths, making nebulae stand out even in light-polluted areas. In particular, for OIII, it transmits emission lines at 495.6nm and 500.7nm to improve the image quality of OIII. ● Highly versatile 48mm American size diameter The filter has a highly versatile 48mm thread diameter and American size, so it can be used with many telescopes. ● Reliable Japanese quality. Synthetic quartz glass is used for the substrate. This filter offers superior strength and heat resistance compared to standard optical glass, resulting in less distortion during coating, greater stability during deposition, and superior surface precision. ■Precautions■ *May not be compatible with all telescopes and lenses. *The performance of this product depends on the angle of incidence of light. For optimal performance, we recommend using it with a telephoto lens or telescope. Using it with a wide-angle lens may result in uneven brightness and color balance in the image. *Please adjust the color balance of captured images using commercially available image processing software. *Product specifications are subject to change without notice. Please be aware of this beforehand.

Filter Size: 48mm Country of Origin: Japan Screw Diameter: 48mm Screw Pitch: 0.75mm Filter Thickness: 1.5mm