Optolong L-Pro filter (1.25")

The Optolong L-pro CCD Depth Filters are filters that reduce the effects of light pollution. Their mechanism of action is to filter out the wavelengths emitted by artificial light, while transmitting the specific wavelengths of the observed objects.

Optolong's L-pro CCD depth filters are made of German Schott glass and have a machining accuracy of at least 1/4 lambda. They transmit more than 90 percent of the light. They have a multi-layer anti-reflection coating and, for durability, a hard, scratch-resistant (IBAD) coating.