This filter was designed for observations of dim and low-contrast deep-sky objects. The passband includes the Hß wavelength (4861 ?) and the OIII doublet (4959 ? and 5007 ?). Some planetary and emission nebulae are emitting up to 90% visible light in this range. This filter, therefore, enhances the contrast of nebulae details from 2–5% to 10–50%. This filter has a barrel diameter of 1.25" and can be mounted on the eyepiece of your OTA.
|Dimensions||3.1×1.2×1.2 in. (8.0×3.0×3.0 cm.)|