Explore Scientific 0310260 Dark-Sky Polarisation filter

Universal Dark Sky filter with 77 mm filter thread for photo lenses. Particularly suitable for enhancing the contrast in polar light and deep sky photography.
The wavelengths of 550 nm (green) and 630 nm (red), which are particularly relevant for polar light photography, are passed through to more than 90%. A special feature of other CLS filters is that only the yellow light of the sodium line is effectively blocked at 590 nm. 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 in polar light photography or photographs of emission nebulae a later removal of the light pollution by post-processing of the photos would be almost impossible.

A reduction of the yellow tones also provides for a better differentiation of red and green tones.
The Explore Scientific Dark Sky Filter can be used to photograph even weaker polar light events from cities.
Especially in times of increasing light pollution, this filter provides extremely good services. In contrast to widely used interference filters (CLS, UHC), this filter can be used without restriction even in front of a wide-angle lens, which is not possible with interference filters. Such filters require vertically incident light and must be mounted between the lens and the camera for wide-angle shots.
The Dark Sky filter is not only of value for the ambitious astrophotographer, it also provides for a 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 suitable without restriction for wide angle lenses. Thus, vignetting-free recordings are possible.

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