Zoom eyepieces offer particularly convenient observing, as one eyepiece covers the same magnifications as a number of fixed focal length eyepieces. You can start at low magnification and then easily increase the magnification, without having to change eyepieces. And you keep the object in view during the entire process. It could not be more convenient.
As soon as you have a planet or deep-sky object in the field of view, you will notice one thing - the fantastic image sharpness. The NightSky zoom eyepiece has a special optical design which provides striking contrast and excellent sharpness, right out to the edge of the field of view. The optical quality really is comparable to that of a fixed focal length eyepiece.
The eyepiece has been designed with baffles to guard against unwanted stray light. This improves the contrast and hence your observing.
Use the same eyepiece for a range of magnifications. This saves both space and your pocket! It is also extremely practical to be able to easily and step-lessly increase from low to high magnification. It allows you to easily find the optimum magnification for the particular astronomical object being observed and for the current seeing conditions.
And so you can keep a firm grip on it in the night, NightSky Zoom has a non-slip ring for the adjustment of the magnification. An arrow and engraved numbers mean you always know which focal length you have selected.