The Lumicon Minus Violet Filter 1.25" greatly improves photographs taken through lenses of any kind. This filter is made from optically flat specially made colored glass, and has anti-reflection coatings on both surfaces.
When you want the maximum clarity you can get from a star, this is the filter to use. Celestial "halos" can obscure and block stars and prevent the viewer from obtaining the best view possible. This filter strips through the excess "glow" around stars and passes only the visible light.
The 1.25" filters employ industry-standard 1.125" x 42 tpi threads (except for Questar/Brandon, which use a thread pattern unique to Questar). The 48 mm filters employ industry-standard 48 x 0.75 mm threading, which thread into 2" eyepieces. All larger filters use the given size with 0.75 mm pitch (e.g. a 72 mm Minus Violet filter has 72 x 0.75 mm threads).
This filter is especially recommended for all telephoto lenses, and will help you obtain pinpoint star images
The Minus Violet filter passes the maximum amount of visible light, including the full blue, green, yellow, and red portions of the spectrum
It absorbs violet and ultraviolet light below 420nm and thus eliminates blue halos around bright stars in color photography
In photography it eliminates bloated and swollen star images caused by violet and ultraviolet light, which telephoto lenses cannot focus exactly, due to chromatic aberration