The 1.25" LRGB Four-Filter Set from Celestron provides the filters for using the LRGB astroimaging technique. This technique entails using a monochrome CCD imager to capture individual images with each of the three colour filters and a fourth, monochrome image, with the luminance filter to provide the brightness. The images are then digitally layered to create a bright full-colour picture of the subject. Each filter also blocks up to 99% of IR wavelengths, which can cause images to appear slightly out of focus, and have anti-reflective multicoatings to increase the transmission of the specific colour of light.
While this set is made for the LRGB imaging technique, they can be used by themselves or stacked, for general astronomy to enhance the viewing of planets and deep space subjects. They fit most 1.25" eyepieces with filter threads from many manufacturers, and with their 26mm clear aperture, they won't encroach on the fields of view for most eyepieces.
Red Filter Uses
- Blocks all light wavelengths except red
- For general astronomy, use this to enhance views of Mars, especially the ice caps, and cloud formations on Jupiter
Green Filter Uses
- Blocks all light wavelengths except green
- For general astronomy, use this to increase the contrast on the lighter areas of Jupiter, and to enhance the polar regions of Saturn and Mars
Blue Filter Uses
- Blocks all light wavelengths except blue
- For general astronomy, this filter is the best for highlighting details on Jupiter and Saturn, and is great for lunar observations
Luminance Filter Uses
- This filter blocks all wavelengths except for Red, Blue, and Green, to provide a bright image with all colours expressed