Explore Scientific Dark-Sky Filter 77mm Slim

A dark-sky filter for camera lenses with a 77mm filter thread, for aurora and deep-sky photography. Made of optical glass with neodymium oxide, it blocks the yellow sodium line at 590 nm and passes more than 90% of the green (550 nm) and red (630 nm) light that is particularly relevant to aurora photography.

Key Features

• Blocks yellow sodium light from street lighting and greenhouse lamps. A camera records yellow as a mix of red and green, so Explore Scientific notes it is virtually impossible to remove later in processing.
• Passes aurora green and red: more than 90% at 550 nm and 630 nm.
• Works in front of a wide-angle lens. Interference filters such as CLS and UHC need light arriving perpendicular to them; this filter can be used in front of a wide-angle lens without restriction.
• 4mm slim mount in black anodized aluminum, for wide-angle images without vignetting.
• Natural color. Fewer yellow tones separate red from green better, for natural night-sky color without complex image processing.

Ideal For

• Aurora photographers, including in towns: Explore Scientific says weaker aurora can be recorded from cities with it.
• Wide-field night photographers shooting the starry sky and time-lapses with wide-angle lenses near street lights.
• Nature and macro photographers: Explore Scientific notes that red and brown tones, such as twilight, sunsets and autumn leaves, are emphasized and better separated.