Considerations When Choosing a Telescope

“What celestial objects do I want to photograph?”

Three possible answers will determine how you proceed:

• Just the moon and beautiful sunsets/sunrises (and maybe wildlife at a distance). If so, all you need is a tripod and possibly an app, like M-Camera, that will allow you more control of your mobile phone camera. Approximate Cost: $30-$50.
• Moon, and basic images of other solar system objects like planets (SEE WARNING about photographing the Sun!!). If so, your minimal requirements are a telescope with mobile phone attachment and an app that allows more control of your phone camera; or a DSLR or dedicated planetary astrophotography camera to attach to the telescope. Approximate Cost: $180-$450 and higher.
• Higher quality images of solar system objects as well as deep sky imaging targets. If so, you’d need a telescope, a star tracker or mount to track celestial objects which move throughout the night, and DSLR or dedicated astrophotography camera. Approximate Cost: 600-up to many thousands of dollars.So far, the economic costs outlined above have been low. In purchasing a telescope, the price range is wide, but the sky is the upper limit! In general, the axiom “you get what you pay for” is true for telescopes. However, get the best telescope you can comfortably afford—after all, you might not grow to love this hobby. It would be a shame to have overextended yourself financially and regret the large amount of money you spent on a telescope, and possibly other equipment, that you don’t use.
  
  • If you answered “1)” or “2)”to the question above, an inexpensive telescope with its own integrated tripod would be minimally sufficient.
    
  • If you answered “3)”, things get more complicated and expensive. And you’d want to obtain a telescope that you could use with a telescope mount or other star tracking device.
    

The simplest telescope is an optical tube holding a single lens that refracts incoming light and focuses it some distance (called the ‘focal length’) behind the lens, allowing for magnification of distant objects. But we cannot be expected to carry around a 6-foot telescope every time we want to look at Jupiter!

Fortunately, by using multiple lenses, we can achieve long focal lengths and greater magnification in a much shorter optical tube. Telescope makers utilize a total of two, or three, or four, or even five carefully matched lenses to achieve long focal lengths in short and manageable optical tubes. The refractor telescopes made with this method are referred to as doublets (two lenses), triplets (three), quadruplets (four) or quintuplets (five lenses). Combining lenses can also be useful in limiting image distortion that occurs with a single lens, such as chromatic aberration.

There are several other telescope types that often employ curved mirrors, rather than lenses, to focus incoming light.  While these designs have some advantages, most experts agree that it is easiest to start out in astrophotography with a refractor. My first telescope was a doublet refractor of medium focal length made by a company called Meade. More than any other manufacturer, Celestron makes both excellent first telescopes and also advanced mass market offerings of astrophotography equipment that are generally well respected.  

My first scope had similar specs to this (except this one has a mobile phone holder):
https://optcorp.com/products/meade-starpro-az-70mm-f-10-doublet-refracting-telescope
Although there are cheaper alternatives for similar specs on paper, with unknown brands the quality of lenses and other optical elements are unknown. Meade and Celestron are unlikely to produce any product of very poor quality components.

Let’s review some good choices for beginner telescopes and other equipment.