The 1.25" O-III filter useful for large aperture telescopes through which the light of the Moon can be extremely overwhelming. Allowing just for the Double Ionized Oxygen lines between 495.9nm to 500.7nm to pass through at 90%
Astrophotographic;The filter enhances contrast during visual observation of gaseous and planetary nebulae in all sky conditions; 1.25" filter allows high-contrast imaging even in areas with strong light pollution
The filter made from high-grade glass with dichroic interference and antireflection coatings;not only useful at light-polluted sites; the contrast is also increased at dark sky sites;it can be used with all 1.25" eyepieces
The O-III filter completely blocks virtually all other visible wavelengths of light so views of nebulas are optimized;increases contrast through selective filtration-Anti-reflection coated to prevent glaring and ghosting
Narrowband filter do not eliminate the effects of light pollution or increase the object's brightness;in many cases, they increase the contrast between nebula and night sky, not brightening the nebula