Nebula filter for increasing contrast; also suitable for use with smaller telescopes
Many objects only first become visible at all when using an UHC filter; but also; highlights such as the Orion; Lagoon or Swan nebulae; show a whole new side to them
Can be used at both light-polluted and dark sky sites; blocks the light from mercury and sodium-vapour lamps
Male thread - M48X0.75; Female thread - M48X0.75; eliminates a range of focusing problems
The extension tube has a M48X0.75 interior thread and a M48X0.75 exterior thread for elegantly solving spacing problems in astrophotography