Newton reflector

From Scope F70076

Newton reflector is the best and cleanest optical system for a reflector that an ordinary person can afford. The others, like Maksutov-Cassegrain and Newton reflectors with an extended focal length, all have some additional lens or glass where the light should go through. Also the almost 1/10 focal ratio (focal length 700mm) is good, as it enables eyepieces with greater focal length for high power, which gives higher quality images, and also all possible aberrations are almost not noticeable at that focal length. It gives also a reasonably wide view at lower magnifications.

Well, the Newton reflector was first made in 1672 by Isaac Newton, and this was a 2 inch telescope, and had an inferior quality metal mirror, so our 3 inch telescope with a glass mirror is much more powerful. To these who don't know what is Newton reflector, Newton reflector is the simplest mirror telescope design where the primary mirror is in the bottom of the tube, and the image is reflected to the focuser at the front of the tube by a flat diagonal (secondary) mirror.

The construct called spider holds the secondary mirror in place, the spider is the first thing which you see when you look into the telescope tube. This spider also causes a little trouble, as it causes spikes in the form of the spider at the brightest objects. This is though not that bad, the spikes can be seen only at the brightest objects which are surrounded by complete darkness, like the brightest stars, and these are considered normal on the astronomical images.

The limiting magnitude of this telescope supposed to be 12 but in my conditions it seems to be 9. This suggests that the visual magnitude limit in my conditions is 2.5 and it is indeed close to that. This means that I can normally see almost 100 stars in the whole sky with the naked eye. The biggest visual magnitude limit with dark skies in a rural environment is considered to be 6, and in the center of the big cities this limit is often 2.