The new STC Astro Urban Sky LRGB filter is the world's first anti-light pollution, ultra-low halo RGB monochromatic filter and has been designed for shooting astronomical deep-sky objects in areas with heavy light pollution such as urban spaces.
The STC Astro Urban Sky SHO Filter can also be included to emphasize the characteristics of nebulae and reveal the unique bright colours of celestial bodies.
The new filter arrives to deliver enhanced results for astrophotographers everywhere, extending the amount of exposure, boosting the colour channel to achieve the highest contrast and stunning images with relative ease.
Feature
SPECIFICATION | |
Supported Size | 1.25" |
31mm frameless | |
36mm frameless | |
48mm Rear threaded | |
48mm Front and Rear threaded | |
50mm frameless | |
50x50 square | |
Threaded pitch | 1.25" : 0.7 48mm : 0.75 |
Frame height(without threaded) |
1.25":0.5cm 48mm Front and Rear threaded:0.4cm 48mm Rear threaded:0.15cm |
Place of production | TAIWAN |
The new STC Astro Urban Sky LRGB Filter blocks artificial light that pollutes the night sky like mercury light (Hg), neon light (Ne) and a large amount of sodium light(Na).
The green (G) and blue (B) channels overlap at doubly ionized oxygen OIII 495.9nm and 500.7nm to enhance the blue-green signal.The red (R) channel contains spectral lines including H-alpha (656.3nm) hydrogen line , NII (654.8nm, 658.3nm) nitrogen lines and SII (672.4nm) sulfur double emission line.The exposure time of three colour filters can be adjusted according to the spectral emission of celestial objects. The STC Astro Urban Sky SHO Filter can also be included to emphasise the characteristics of nebulae and reveal the unique bright colours of celestial bodies.
The Luminous (L) channel is an UV-IR Cut filter which allows wavelengths 380~680nm to pass. One can also use STC Astro Multispectra Filter (MS) to replace L filter in heavy light polluted areas. MS filter not only cuts wavelengths below 380nm and above 680nm, it also blocks out mercury (Hg) and sodium (Na) light pollution. The mashup of filters may be a good option for those who prefer clean and high signal images.