Dark-Sky Filter 77mm Slim

Universally applicable dark sky filter with 77mm filter thread for photo lenses. Particularly suitable for increasing contrast in aurora and deep-sky photography.

The wavelengths of 550nm (green) and 630nm (red), which are particularly relevant for aurora photography, are transmitted to more than 90%. A special feature of other so-called CLS filters is that only the yellow light of the sodium line is effectively blocked at 590nmwill. This effectively suppresses sodium vapor lamps from street lighting and greenhouses (assimilation light). This is a clear advantage because the yellow light for the digital camera is always registered as a mixture of red and green. Especially with aurora photography or recordings of emission nebulae, later removal of the light pollution by post-processing the photos would be virtually impossible.

A reduction in yellow tones also ensures a better differentiation between red and green tones.

With the Explore Scientific Dark-Sky Filter, weaker aurora events from cities can also be detected photographically.

Especially in times of increasing light pollution, this filter does an extremely good job. In contrast to widely used interference filters (CLS, UHC), this filter can also be used without restriction in front of a wide-angle lens, which is not possible with interference filters. Such filters require perpendicularly incident light and have to be installed between the lens and the camera in a complex manner for wide-angle recordings.

The dark sky filter is not only of value for the ambitious astrophotographer, it also ensures natural color reproduction of the night sky without complex image processing .

In nature and macro photography red and brown tones (e.g. twilight colors, sunset, autumn leaves) are emphasized and better differentiated.

Due to the very flat design (slim) of only 4mm, this filter is also fully suitable for wide-angle lenses. This means that vignetting-free recordings are possible.

Test images taken by Bernd Pröschold - www.sternstunden.net

Comparison test at: http://www.sternstunden.net/filter-testing.html

• Dark-Sky filter
• Contrast increase in aurora & deep-sky photography
• Reduction of stray light from street lights, for example
• Wide-angle shots of the starry sky, time-lapse shots
• Blocks yellow light, not possible with image editing
• Black anodized aluminum housing
• 77mm filter thread for photo lenses
• Construction height only 4mm (Slim)
• Suitable for wide-angle lenses
• Made of special optical glass with neodymium oxide