The Singh-Ray 77mm Astro-Vision Filter is designed to reduce the appearance of light pollution in images or video that include the night sky and illumination from artificial light sources. This effect can be obtained when this filter is used on a film camera system with daylight film installed or on a digital camera system with its daylight white balance setting selected.
Light pollution occurs in areas of the night sky that are above or near concentrated and intense sources of artificial light such as cities. These light sources can include exterior and interior lamps for commercial or residential buildings, brightly lit advertisements such as billboards, streetlamps, as well as sports and entertainment venues. Together they can result in a type of light pollution known as sky glow, where individual stars, the Milky Way, and other astronomical features in the night sky are obscured. Additionally, artificial lights clustered together can become difficult to individually discern. Light pollution from these "cluttered" sources can become a source of distraction within an image and can resemble overexposed areas of glare.
When used, the Singh-Ray 77mm Astro-Vision Filter can improve the results of nighttime images by absorbing the yellow light from sodium-vapor lamps or mercury-vapor lamps, common light sources within urban areas. By preventing the dominant wavelengths of light associated with the color of those lamps from being recorded, the visibility of astronomical objects is enhanced, and artificial light sources are more clearly defined with less glare and improved contrast.
This filter is constructed from optical glass and features a thin, 4.3mm aluminum alloy filter ring for durability, which also minimizes the potential for vignetting while remaining lightweight. The filter ring also includes 77mm front threads that allow for use with other filters that have 77mm rear threads.
- Reduces the appearance of light pollution in video or images that include the night sky and minimizes illumination from artificial light sources
- For cameras with daylight film installed or a digital camera system with its daylight white balance setting selected
- Absorbs the yellow light from sodium-vapor lamps or mercury-vapor lamps, common light sources within urban areas
- Enhances the visibility of astronomical objects, and where they appear, artificial light sources are more clearly defined with less glare and improved contrast
- 1.4x filter factor reduces exposure by 0.5 stop
- Non-coated, constructed from optical glass for clarity
- Aluminum alloy filter ring for durability while remaining lightweight
- 77mm front filter threads allow for use with other filters
- Top knurlings provide a more textured grip when mounting or removing filter from a lens
- Padded pouch for storage and transport