Factors to Consider
from NightWatch, by Terence Dickinson
| Telescope Type | Will Telescope Usually Be Transported to Observing Site? | Is the Main Observing Site an Urban Location or a Dark Rural Location? | Will Telescope Be Used For Celestial Photography? |
| 2.4″ to 4″ achromatic refractor | generally easily transportable | good performance in an urban environment, will not equal other types under dark skies | not recommended except for shooting the moon |
| 3″ to 7″ apochromatic refractor | easily transported up to 5″ size; larger models are hefty | a good choice if you are limited to mostly urban and some rural observing | a favourite for astrophotographers |
| 4″ to 8″ Newtonian reflector, equatorial mount | easily transported, although some 8″ units are bulky | good all-round performer | astrophoto versions often have beefier mounts and specialized accessories |
| 10″ or larger Newtonian reflector, equatorial mount | 10″ units are about the limit for convenient transport | performance limited in an urban environment; excellent performer under dark skies | will yield excellent results but only with massive mount and proper accessories |
| 4″ to 8″ Newtonian reflector, Dobsonian mount | easily transported | good all-round performer | not recommended |
| 10″ or larger Newtonian reflector, Dobsonian mount | transportable, but van may be needed | urban environment severely limits usefulness of this type, designed for use under dark skies | not recommended |
| 4″ to 8″ Schmidt-Cassegrain | easily transportable in any vehicle | good all-round performer | excellent range of accessories for backyard photographer |
| 3.5″ to 7″ Matsukov-Cassegrain | exceptionally compact in smaller apertures | often a favorite for urban astronomers, who occasionally observe from really dark sites | long focal ratio limits photography to moon or ccd imaging |
| Telescope Type | Will Telescope be Primarily Used For Observing Sun, Moon Planets and Other Bright, Easy-To-Find Objects? | Will Telescope be Used For Viewing Nebulas, Star Clusters and Galaxies? | Will Telescope Frequently Be Used For Daytime Land Viewing? |
| 2.4″ to 4″ achromatic refractor | excellent performance, long focal ratios and equatorial mount preferred | not recommended | suitable and recommended |
| 3″ to 7″ apochromatic refractor | unsurpassed for consistently fine lunar and planetary performance. The preferred choice if you can afford one | excellent definition and contrast but limited by their aperture | Tele-Vue “Pronto” and Astro-Physics “Traveler” especially recommended for daytime viewing |
| 4″ to 8″ Newtonian reflector, equatorial mount | generally good performance, used to be standard planetary telescope until advent of apochromatic refractors in 1980s | 6- and 8-inch models especially recommended | not recommended |
| 10″ or larger Newtonian reflector, equatorial mount | good results obtained in medium focal ratios with premium optics | top-rated for deep-sky viewing | not recommended |
| 4″ to 8″ Newtonian reflector, Dobsonian mount | generally good performance, although mounts not intended for continuous high-powered plantary viewing | 6- and 8-inch models especially recommended | not recommended |
| 10″ or larger Newtonian reflector, Dobsonian mount | these telescopes are not designed for viewing bright objects, and seldom produce satisfactory views compared with other types | very popular as the most economical way to see the faint fuzzies. Excellent at low powers, which are used most of the time anyway | not recommended |
| 5″ to 16″ Schmidt-Cassegrain | although apochromatic refractors are best in this category, the Schmidt-Cassegrain offers good planetary views | deep-sky performance rivals that of any other telescope type | suitable in smallest sizes |
| 3.5″ to 7″ Maksutov-Cassegrain | when well-made, this design seems to produce performance second only to the refractors | in most common size(3.5 inch), these instruments are less effective than other types simply because of low light-collecting power | ideal in 3.5-inch size |