Description Kson 495nm Longpass Filter Brilliant Fringe Killer / Semi-APO Alternative Yellow 495nm Longpass filter. Suppresses the secondary blue spectrum when using achromatic and half-apochromatic refractors (increasing image sharpness). For visual and photographic planetary observations. Enhances contrast between the belts on Jupiter. Increases contrast of the lunar and Martian surface. Multi-coated for max contrast, no reflections, scatter or dimming. We can say a bit more about these filters. If you have an Achromat, these will significantly help with clarity and fringing as well. It allows a lot of the light through while still eliminating the purple fringing. There is also less of a color shift compared with the #12 filter. It may also darken your suburban sky. If you want to try a further experiment, try adding one of our Moon and Skyglow filters to it to restore much of the image neutrality.
