Telescopes for Astronomy, Pro 400-70MM Refractor Telescope for Beginners Adults Kids with Adjustable Tripod, Photo Shutter, 4 Moon Filter, Phone Adapter Mount and Backpack

1. Eyepiece: There are two main functions of the eyepiece: one is to continue to enlarge the image formed by the objective lens; the other is to turn the outgoing beam into parallel light, so that the observation is more comfortable and convenient. There are many types of eyepieces, and there are three commonly used ones: Huygens (H), which are suitable for low magnification observations; Ramsden (R), which are also suitable for low and medium magnification observations. ; Kener (K), is an improved version of Ramsden, which eliminates Ramsden's chromatic aberration. This eyepiece has a large field of view and is often used for low-magnification observations, such as comets or large-area celestial bodies. (our telescope equip with K-series eyepieces).
2. Finder scope: In order to quickly find the target to be observed during observation, a finder scope is usually attached to the main mirror to help you aim at the target. Its optical axis is parallel to the primary telescope, so that it remains aligned with the primary telescope's target. The finder scope generally has a small magnification, but a larger field of view, it is easier to find the target, after finding the target position, please switch to the main telescope to observe.
3. Diagonal mirror: Don't be troubled by the upside-down images when observing, our telescope use an 45° diagonal mirror to correct an inverted image into an erect image. It is generally used when observing terrestrial targets, and it is not necessary to observe the sky space.
4. Mobile phone holder: It is used by astronomy enthusiasts for astrophotography or landscape photography to connect mobile phones and telescopes. after connection, they can take pictures/videos and share them on social medias.

Formula 1: Magnification = Focal Length / Eyepiece Diameter

400MM Focal /K25MM Ocular =16X Magnification

400MM Focal /K6MM Ocular =66.7X Magnification

Formula 2: Limit magnification of refracting telescope = Aperture(mm)*1.2

Limit magnification (50mm aperture)= 60X

Limit magnification (60mm aperture)=72x

Limit magnification (70mm aperture)=84X

Taking a telescope with an objective lens diameter of 70mm as an example, the theoretical limit magnification it can achieve is 84X, that is why we do not pursue "high magnification", but pursue higher quality.