Backyard Stargazing: Best Metrics for Amateurs

For an amateur eyeing stars and planets from a UK backyard, you want versatility to see bright planets like Jupiter, plus some star clusters. Light pollution limits deep-sky hunts, so focus on balance. Here’s the optimal range, with costs in GBP based on 2025 trends (e.g., Celestron, Sky-Watcher):

Metric	Optimal Range	Why It Works	Cost (GBP)
Aperture	100-200mm (4-8 inches)	Grabs enough light for planets and bright stars; manageable size.	£200-£600
Focal Length	600-1,200mm	Balances zoom (planets) and width (clusters); fits most eyepieces.	Included in scope
Focal Ratio	f/6-f/10	Bright enough for stars, sharp for planets; good all-rounder.	Included in scope
Magnification	20x-150x (with eyepieces)	Low for wide views, high for planetary detail; max 2x aperture.	£20-£50 (eyepieces)
Lens/Mirror Quality	Multi-coated or parabolic	Cuts distortion affordably; ED glass optional for purists.	£50-£150 extra
Mount Type	Alt-azimuth or Dobsonian	Simple setup, tracks by hand; equatorial if photos matter.	£50-£200
Field of View	1-2°	Shows constellations and planets in context; easy to navigate.	Eyepiece dependent
Resolution	1.15-0.58 arcseconds	Splits doubles, sharpens moons—100-200mm aperture nails it.	Tied to aperture
Portability	5-15 kg	Light enough to move, big enough to see—fits a shed or car.	Included in scope
Total Cost		Scope + basic eyepieces and mount	£300-£1,000

• Example Scope: A Sky-Watcher 150mm f/8 Dobsonian (£350) with 25mm and 10mm eyepieces (£40) hits 48x and 120x—great for Mars’ ice caps or Orion’s stars.

• Why This Range: Balances light gathering (100-200mm), detail (f/6-f/10), and ease (alt-azimuth). Costs stay reasonable—£300-£1,000 gets you years of fun.