Pegasus Astro 2inch mounted photographic filter - Blue

This filter is designed as the Blue (B) component for LRGB (Luminance, Red, Green, Blue) deep-sky astrophotography. It isolates the 410-500nm wavelength range, which is crucial for capturing the natural color of star-forming regions, reflection nebulae like the Pleiades (M45), and the spiral arms of galaxies.

Yes. This filter uses the standard M48x0.75 thread pitch, which is the industry standard for 2-inch mounted astronomical filters. It is compatible with virtually any 2-inch filter wheel, filter drawer, or accessory that accepts 2-inch filters.

Parfocal means the filter is manufactured to a specific thickness (2mm glass in this case) so that the focal point of your telescope does not shift significantly when you switch between it and other parfocal filters in a set (like Red and Green). This minimizes or eliminates the need to refocus your camera, streamlining your imaging sessions.

A 1/4 wavefront polish ensures the filter's glass surface is extremely flat and will not distort the incoming light. For a target like the Andromeda Galaxy (M31), this translates to sharper star points within its spiral arms and a clearer definition of its dust lanes, preserving the fine detail resolved by your telescope's main optics.

High transmission means more light from your target reaches the camera sensor in less time. With >95% average transmission in its 410-500nm bandpass, this filter allows you to capture a stronger signal for the blue channel with shorter sub-exposures, improving your overall signal-to-noise ratio and revealing fainter details.

While designed for photography, you can use it visually. However, as a bandpass filter, it will impart a strong blue tint to everything and significantly dim the view. It is not a color-correction or light pollution filter and is generally not recommended for visual use as it will not enhance detail on most objects in the way a nebula filter would.