Optolong SII 3nm CCD 36mm Unmounted Filter
| Article number: | SIICCD3-36U |
| Availability: | More on the Way to us |
| Delivery time: | More on the Way to Us |
The SII corresponds with the RGB channel, allowing imagers to process Hubble images with post-processing astrophotography software. Optolong uses a multi-layer, anti-reflection coating on the filter. It uses a non-cementing optical substrate coating, which is applied through precision Ion-based deposition, providing durability and resistance to scratching. It also provides stability on the central wavelength so there is no deviation depending on temperature change. Their planetary rotation system gives precision and homogenous coatings to ensure high-value pass-band transmission and off-band optical density.
The SII (Sulfur II) CCD filter is an extra narrowband filter designed for nebula observation. The SII filter from Optolong allows a 3nm bandwidth of light centered on a wavelength of 672 nm though. This filter reduces certain types of light transmission like artificial light from mercury vapor and both high/low-pressure sodium vapor lights. They also block natural light transmissions caused by neutral oxygen emission in our atmosphere, often called sky glow.