Advantages of Newtonian Reflector Telescopes Viewing Deep-Sky Objects
One of the best things about their design is that they are straightforward yet still yield a large aperture for a lower cost. They have a vast field of view, so they can be excellent for imaging or viewing deep-sky objects.
Reflector or Refractor?
Astronomers ultimately face one of two choices when choosing a telescope at a basic level. The decision can be challenging, but there are a few points to consider.
The largest aperture for your money will be a Newtonian reflector. As astronomy is all about capturing dim light, this is a serious consideration.
However, reflectors require regular collimation to ensure you get the best out of them.
On the other hand, a Newtonian Reflector Telescopes Viewing Deep-Sky Objects will remain collimated for years.This makes it an ideal grab-and-go telescope for those who like to travel to a local dark-sky site or even further abroad. The collimation process for a reflector is quickly learned and fast to implement at the start of an observing session.
Mounting any telescope on a unwieldy mount will soon make you lose interest. Which is why a stable Dobsonian reflector is such a popular and recommended choice.
There is a well-known maxim in astronomical circles: “The best telescope is the one you use the most.” One that doesn’t produce inspiring views. Or is challenging to set up and operate will sit unused in a corner quickly.
If you are new to astronomy and are trying to decide what telescope you should buy. Read our guide to the best telescopes for astronomy beginners.
What is the disadvantage of a Newtonian telescope?
One disadvantage of Newtonian Reflector Telescopes Viewing Deep-Sky Objects compared with refractors is the shadow produced on the incident light by the secondary mirror. Depending on the size of the secondary mirror, a lesser amount of light gets to the eye than initially enters the telescope tube. This is also known as ‘obstruction.’
In a reflecting telescope, the secondary mirror prevents or obstructs some incoming light from reaching the primary mirror. The central obstruction is the proportion of obstructed light expressed as a percentage of the incoming light.
The most crucial aspect of any telescope is its aperture. The diameter of its main optical component, which can be either a lens or a mirror. A scope’s aperture determines its light-gathering ability. (How bright the image appears.) And its resolving power (how sharp the image appears).
Refractor vs. Reflector:
Refractor or newtonian reflector? That is the question. Whether it is nobler to view the night sky unfettered by diffraction spikes or go deeper to enjoy spiky stars. Diffraction spikes are lines radiating from bright light sources. Causing what is known as the starburst effect or sun stars in photographs and vision.
It’s a case of using what instrument is best for any given purpose, along with your aesthetic tastes.
Here are several key considerations:
Newtonian Reflector Telescopes Viewing Deep-Sky Objects
Are you interested in photographing a very faint object? Perhaps a faint Cepheid variable star? A large reflector will collect a lot more light, and the resulting small field of view is not a problem.
If you are interested in a moderately wide field, say enough to capture the Orion nebula? Then a short focal length telescope will get more of the sky onto the film of a given size. Plate scale (in arcseconds/mm) and the amount of the sky shown in your image depends only on the telescope’s focal length.
The telescope’s focal ratio is critical for photographs of nebulae and galaxies! The brightness of stars (point sources) is proportional to D2 (the telescope’s diameter and D2 are proportional to the collecting area, pi*R2). However, the brightness of a nebula is proportional to D2/FL2 since the image of the nebula is also spread out over x and y dimensions by an amount proportional to the focal length (FL).
Reflecting telescopes
Reflecting telescopes, with their secondary mirror (generally with mirror supports), often produce “diffraction spikes” around star images. While not aesthetically objectionable, any obstructions can degrade the picture. Refractors are okay with this problem.
Refractors
The refractor telescopes generally have the edge over newtonian reflector telescopes for a quality image. Both from lens/mirror quality and precision optical mountings and lack of central obscurations. Equally important in a choice of telescope type is the focal length and the resulting field of view.
