TheHoya Starscape Filter is designed to block light pollution from city lights, giving final night time images a more natural look.The filter targets specific wavelengths of light emitted by common sodium and mercury vapor street lamps and blocks a portion of that orange/yellow glow as it passes through the filter. The effect can be dramatic or subtle depending on how strong the light source is and how much atmospheric haze is in the air.
The filter is not adding blue or changing the color of the scene. It is stopping specific areas of the color spectrum from passing through the filter. The camera never sees that light or color.
The end result is a RAW file without the yellow-orange glow polluting your image. It allows you to color correct and enhance colors without needing to compensate for light pollution.
The filter can also be used during the daylight hours to enhance red, orange and yellow colors. It was originally created for film photographers to "intensify" warm fall colors on overcast and cloudy days. The filter is still used today by digital and film photographers to target those specific colors for enhanced saturation while leaving the blue and green colors alone. Add a circular polarizer to this and you will have an excellent filter combination to capture fall colors.
Features:
For Astro and Milky Way photographers
Blocks yellow-orange color cast from city lights
Improves contrast between stars and sky
Enhances fall colors without affecting green or blue colors
Technical Specs: Filter Size:49mm Filter Factor:0.5 stops Glass Type:Hoya Didymium Number of Multi-Coatings:0 Hardened Top Layer:No Anti-Static:No Frame Construction:Low Profile / Aluminum Front Filter Threads:Yes
Notes: *The Starscape filter has a base filter factor (light loss) of 1/2 stop, but you may see a 1-2 stop difference in exposure depending on how much of your scene is lit by sodium or mercury vapor lights.
*The Hoya Starscape and Hoya Intensifier Filters use the same glass and filter frame. The only difference is the name and packaging.
*The Starscape filter has many names: Starscapes, Intensifiers, Red Intensifiers, Ra54s, Light Pollution filters, and/or "didymium" filters essentially reduce the yellow-orange glow caused by city lights.
