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Celestron Travel Scope 70 vs Celestron AstroMaster 90AZ

Both are achromatic refractors on alt-azimuth mounts with no maintenance requirements, which makes them look like the same telescope in two sizes. In practice the AstroMaster 90AZ is a serious astronomical instrument and the Travel Scope 70 is a genuinely portable one, and that difference matters more than the 20mm of aperture.

The short answer

Buy the 90AZ as your main telescope; buy the Travel Scope 70 if portability is the actual requirement or as a second grab-and-go instrument.

Specifications side by side

Specification comparison between the Celestron Travel Scope 70 and the Celestron AstroMaster 90AZ
SpecificationCelestron Travel Scope 70Celestron AstroMaster 90AZ
Price₹12,000₹25,000
Aperture70 mm90 mm
Focal length400 mm1000 mm
Focal ratiof/5.7f/11
Optical designAchromatAchromat
MountAlt-AzAlt-Az
GoToManualManual
Max useful magnification140×180×
Experience levelBeginnerBeginner
Best suited toPortablePlanetary

What you'd see through each

The same target through both telescopes, each drawn from its own aperture and focal length.

Celestron Travel Scope 70

70mm · 400mm focal length

At 40×, Saturn looks about as wide as the full Moon does to your naked eye — small, in a wide field.

  • The rings, separated from the globe
  • The Cassini Division in the rings, on a steady night: — needs about 200mm or more
How we calculated this
Magnification: 40×
400 mm focal length ÷ 10 mm eyepiece = 40×
True field of view: 1.25°
50° apparent field ÷ 40× = 1.25°
How big it looks: 0.46°
41″ across the rings × 40 = 0.46° — about 88% of the width of the full Moon to your naked eye
Resolving power (Dawes limit): 1.66″
116 ÷ 70 mm = 1.66″ — the finest detail the optics can separate in perfect air
Limiting magnitude: 11.7
7.5 + 5 × log₁₀(7 cm) = 11.7 — the faintest star under a truly dark sky
Light grasp: 100×
(70 mm ÷ 7 mm pupil)² = 100× your dark-adapted eye

Magnification uses the same 25mm (Moon, nebula) and 10mm (planets) reference eyepieces as the specifications above. Which features appear is not a formula: each is shown from the aperture at which our own guides say it becomes visible. Star positions and crater positions are illustrative; how many appear follows the limiting magnitude and resolving power.

Celestron AstroMaster 90AZ

90mm · 1000mm focal length

At 100×, Saturn looks about 2.2× as wide as the full Moon does to your naked eye — small, in a wide field.

  • The rings, separated from the globe
  • The Cassini Division in the rings, on a steady night: — needs about 200mm or more
How we calculated this
Magnification: 100×
1000 mm focal length ÷ 10 mm eyepiece = 100×
True field of view: 0.50°
50° apparent field ÷ 100× = 0.50°
How big it looks: 1.14°
41″ across the rings × 100 = 1.14° — about 2.2× the width of the full Moon to your naked eye
Resolving power (Dawes limit): 1.29″
116 ÷ 90 mm = 1.29″ — the finest detail the optics can separate in perfect air
Limiting magnitude: 12.3
7.5 + 5 × log₁₀(9 cm) = 12.3 — the faintest star under a truly dark sky
Light grasp: 165×
(90 mm ÷ 7 mm pupil)² = 165× your dark-adapted eye

Magnification uses the same 25mm (Moon, nebula) and 10mm (planets) reference eyepieces as the specifications above. Which features appear is not a formula: each is shown from the aperture at which our own guides say it becomes visible. Star positions and crater positions are illustrative; how many appear follows the limiting magnitude and resolving power.

Illustration of a typical view under a dark sky. City skies and atmospheric conditions will show less. The square close-ups are enlarged to show detail; the circles are to scale.

Choose the Travel Scope 70 if

₹12,000

  • The telescope needs to travel — treks, holidays, trips to darker skies
  • You want something that doubles as a daytime spotting scope
  • You are buying for a younger child who needs to handle it themselves
  • Budget is the binding constraint
Full specifications for the Travel Scope 70 →

Choose the AstroMaster 90AZ if

₹25,000

  • This will be your main telescope for backyard or balcony observing
  • You want meaningfully more light and higher usable magnification
  • You want a mount steady enough for sustained planetary observing
  • You want a telescope that will still satisfy you in three years
Full specifications for the AstroMaster 90AZ →

What the spec table does not tell you

The specification gap understates the practical one. The 90AZ has about 1.65 times the light-collecting area, but it also has a far steadier mount and a much longer focal ratio — f/11 against f/5.7 — which means dramatically better performance at the high magnifications planets require. The Travel Scope is excellent at what it is for; it is not a smaller version of the 90AZ.

Frequently asked questions

Which is better, the Celestron Travel Scope 70 or the Celestron AstroMaster 90AZ?
Buy the 90AZ as your main telescope; buy the Travel Scope 70 if portability is the actual requirement or as a second grab-and-go instrument.
What is the price difference between the Travel Scope 70 and the AstroMaster 90AZ?
The Travel Scope 70 is ₹12,000 and the AstroMaster 90AZ is ₹25,000 — a difference of ₹13,000. The AstroMaster 90AZ is the more expensive of the two.
How do the apertures compare?
The Travel Scope 70 has 70mm and the AstroMaster 90AZ has 90mm. That means the AstroMaster 90AZ collects about 1.65× as much light, which matters most on faint deep-sky objects and very little on the Moon and planets.

Related comparisons and guides

ComparisonCelestron AstroMaster 90AZ vs 130EQBuy the 90AZ if you value simplicity and mainly observe the Moon and planets; buy the 130EQ if you want the most capability and are willing to learn collimation and an equatorial mount.GuideHow to choose a telescopeFour questions about your circumstances that make the specifications obvious.Buying guideBest telescopes in IndiaRanked picks across every budget, with the caveat each one carries.