Despite the long focal length of the Schmidt-Cassegrain optics, the tube offers a very short design, which makes the system a compact telescope with extremely light transport characteristics. The light hits an aspherically shaped Schmidt correction plate and is projected further onto the spherical main mirror. This reflects it onto a secondary mirror, which reflects it back towards the main mirror. The light beam now passes through the main mirror, which has a central hole. In this way the light is thrown into the eyepiece extension at the lower end of the tube. The system is thus closed and does not suffer from air turbulence, which could worsen the image. Of course, this also provides optimum dust protection. The Schmidt plate is multi-coated, which ensures bright and low-reflection images. This optics offers a very good image, contrast and sharpness convince and offer great fun when observing the planets. The Schmidt-Cassegrain system is a good all-round device for observation and photography with a huge range of optional accessories. The view at the lower end of the tube allows easy orientation. The telescope can also be used optimally for occasional earth observations (e.g. in the close range for bird observations). The Celestron SC optics are designed for an aperture ratio of around 1:10, therefore astrophotography is still very well possible.