Astromania Zoom Eyepiece, FMC 7 to 21mm Telescope Eyepiece 1.25 Inch Metal Accessory, For Moon Planets Deep-Sky Astronomy Objects, Lense Visual Observation

Telescope zoom eyepiece changes focal length from 21mm to 7mm for providing a variety of viewing magnification powers; Excellent contrast and sharpness make 7-21mm zoom eyepiece also of interest for planetary observing lunar detail and deep sky objects Exceptionally long 16-33mm eye relief range help to change magnification power without physically changing eyepiece; Make it a versatile variable magnification eyepiece; Rubber eyecup provide comfortable view as well as for convenience of eyeglass wearers Apparent field of view is 30 degrees at 21 mm and 47 degrees at 7 mm; rubber traction ring ensures a good grip; the 1.25 inch barrel is threaded for standard filters. Actual magnification range will depend on the focal length of your telescope, so you can use this zoom telescope eyepiece with refractors, reflectors, and catadioptric models. Rubber traction ring ensures a good grip; 1.25 inch barrel is threaded for standard filters; Actual magnification range will depend on the focal length of your telescope so use this zoom telescope eyepiece with refractors reflectors and catadioptric model Astromania zoom eyepiece consists of four elements which are multi coated with anti-reflection coatings for clear and high contrast astronomical viewing; Large eye lens coupled with long eye relief means zoom provides particularly good viewing comfort Comfortable viewing at every focal length setting superior to most fixed focal length eyepieces especially at shorter focal length settings; Precise and stepless adjustment from 7-21mm gives smooth control, making this nice value in quality zoom eyepiece This 1.25 inch zoom eyepiece is compatible with all standard 1.25" focusers and diagonal mirrors; The built-in filter thread accepts moon filters UHC filters and OIII filters while also combine it with 2x barlow lens for even higher power views This 7-21mm zoom eyepiece lets you quickly switch from low power sweeping of star clusters to high power views of Jupiter's cloud bands and Saturn's rings; It is an excellent choice for both daytime terrestrial viewing and nighttime deep sky observation