OpCS77
OPTOLONG Clear Sky Light Pollution Filter, 77mm Thread
Optolong Clear Sky Filter is the first new item in 2017 from Optolong Optics Co.,Ltd.Clear Sky blocks the city Na and Hg light pollution so that improve contrast effectively.The main point of this filter that differ with other filter, its front facing,77mm, you can twist it in front of camera lens directly like UV lens. More important is its performance, no wavelength shifting, no color gradient through the Images.
