7-inch telescopes are basically for amateurs though there are some advanced telescopes for professional astronomers with this aperture. Overall, they provide 500-2700 mm focal lengths, and a range of focal ratios from f/2.8-f/15. They can magnify objects 356 times the human eye. They also can resolve double stars at 0.65 arcsec. You can get 7-inch telescopes from different brands in the price range of 1,350-5,500$.
What is a 7-inch telescope?
A 7-inch telescope refers to a telescope having an aperture (the diameter of the objective lens) of 7-inch (180 mm). A 7-inch telescope is considered to be in the category of a medium size telescope.
What can you see with a 7-inch telescope?
- The Moon and its craters
- Jupiter with its cloud belts, and the Great Red Spot
- Saturn and its bands, the Cassini Division
- Uranus and Neptune
- Galaxies like M 83, Whirlpool Galaxy, M81 and M82
- Globular star clusters like M5, M13, M15, and M92.
- Nebulae like NGC 7027 in Cygnus, etc
Types and Technical Specifications of 7-inch telescope
Types (Optical Design)
Dall Kirkham: Example: Takahashi Mewlon 180 C· f/ 12 Dall Kirkham Reflecting Telescope.
Hyperbolic Newtonian: Example: Takahashi Epsilon E-180 180mm ED Astrograph OTA.
Maksutov Cassegrain: Example: Sky-Watcher 180mm Maksutov Cassegrain Telescope OTA, Celestron CGX 700 Maksutov Cassegrain Telescope, Celestron CGEM II· 700 Maksutov Cassegrain, Celestron 700 f/15 Maksutov Cassegrain OTA, Celestron Advanced VX 700 Maksutov Cassegrain Telescope Bundle – CE-12035.
Maksutov Newtonian: Example: Sky-Watcher 190mm Maksutov-Newtonian Telescope OTA.
Technical Specifications
Aperture: 7-inch (180 mm)
Focal Length: 500-2700 mm
Focal ratio: f/2.8-f/15
Highest Magnification: 360x
Light Gathering Power: 660x
Price: 1,350-5,500$
Images taken with 7-inch telescopes
Examples of 7-inch telescopes
- Celestron Advanced VX 700 Maksutov Cassegrain Telescope Bundle – CE-12035
- Celestron 700 f/15 Maksutov Cassegrain OTA
- Celestron CGEM II· 700 Maksutov Cassegrain Telescope
- Celestron CGX 700 Maksutov Cassegrain Telescope
- Sky-Watcher 190mm Maksutov-Newtonian Telescope OTA
- Sky-Watcher 180mm Maksutov Cassegrain Telescope OTA
- Takahashi Epsilon E-180 180mm ED Astrograph OTA
- Takahashi Mewlon 180 C· f/ 12 Dall Kirkham Reflecting Telescope
How do 7-inch telescopes compare to other size-telescopes
7-inch vs 8-inch telescope
8-inch telescopes provide focal lengths of 800-2415 mm (f/4-f/11.5), while 7-inch vary in focal lengths from 500-2700 mm ( f/2.8-f/15). On average 8-inch telescopes provide the highest magnification of 300-480x, whereas 7-inch telescopes can magnify 360x. However, their price range is similar, sometimes 7-inch telescopes cost more than 8-inch telescopes.
| 7-inch telescope | 8-inch telescope | |
| Aperture | 7-inch (180 mm) | 8-inch (203 mm) |
| Focal Ratio | f/2.8-f/15 | f/4-f/11.5 |
| Focal Length | 500-2700 mm | 800-2415 mm |
| Highest Magnification | 360x | 300-480x |
| Price | 1,350-5,500$ | 570-5,000$ |
7-inch vs 9.25-inch telescope
7-inch telescopes provide a focal length of 500-2700 mm with a focal ratio of f/2.8-f/15. In contrast, 9.25-inch telescopes vary from 2350-2500 mm in focal length with a focal ratio of f/10. Moreover, 9.25-inch telescopes provide 406-555x the highest magnification, which is 360x in the case of 7-inch telescopes.
| 7-inch telescope | 9.25-inch telescope | |
| Aperture | 7-inch (180 mm) | 9.25-inch (235 mm) |
| Focal Ratio | f/2.8-f/15 | f/10 |
| Focal Length | 500-2700 mm | 2350-2500 mm |
| Highest Magnification | 360x | 406-555x |
| Price | 1,350-5,500$ | 1,899-8,320$ |
7-inch vs 10-inch telescope
7-inch telescopes have less aperture than the 10-inch telescopes. They offer a focal ratio of f/3.9-f/10 whereas the 7-inch telescopes provide f/2.8-f/15. Besides, 7-inch telescopes offer a focal length of 500-2700 mm whereas the 10-inch telescopes vary from 1000-2500 mm in focal lengths. Though sometimes you can get 10-inch telescopes at a lesser price than a 7-inch scope.
| 7-inch telescope | 10-inch telescope | |
| Aperture | 7-inch (180 mm) | 10-inch (254 mm) |
| Focal Ratio | f/2.8-f/15 | f/3.9-f/10 |
| Focal Length | 500-2700 mm | 1000-2500 mm |
| Highest Magnification | 360x | 500-600x |
| Price | 1,350-5,500$ | 630-10,000$ |
7-inch vs 11-inch telescopes
7-inch telescope has less aperture than the 11-inch telescopes. They offer a focal ratio of f/2.8-f/15 whereas the 11-inch telescopes vary from f/2.2-f/10. Besides, 11-inch telescopes offer a focal length of 620-2800 mm whereas the 7-inch telescopes start from 500 mm to 2700 mm mm in focal lengths. Moreover, 7-inch telescopes provide 360x the highest magnification, whereas 11-inch telescopes can magnify up to 558-558.8x..
| 7-inch telescope | 11-inch telescopes | |
| Aperture | 7-inch (180 mm) | 11-inch (279 mm) |
| Focal Ratio | f/2.8-f/15 | f/2.2-f/10 |
| Focal Length | 500-2700 mm | 620-2800 mm |
| Highest Magnification | 360x | 558-558.8x |
| Price | 1,350-5,500$ | 2,400-6,500$ |