SpectrumOI TourStar Pro 90 AZ
$188.59 price checked August 2026
If you want a smartphone telescope with high transmissive glass eyepieces, this is the one to price-check.
What the TourStar Pro 90 Is, and Who For
The SpectrumOI TourStar Pro 90 AZ is for the beginner astronomer who needs to resolve lunar craters and Jupiter’s moons, as its 90mm aperture clears the 70mm minimum diameter threshold.
Blurry images of the Moon or Jupiter often stem from using a telescope with an aperture too small to collect sufficient light. When the optics cannot resolve fine details like craters or cloud bands, the experience of stargazing feels limited to vague shapes rather than clear celestial features.
The SpectrumOI TourStar Pro 90 AZ provides a solution with a 90mm aperture, which exceeds the 70mm threshold required for clear lunar and planetary resolution. This size ensures that you can see distinct details that smaller beginner scopes might miss.
We evaluated the other refractor telescope options we compared to select the best performers for this category. This review is for the user looking to upgrade from a basic starter scope to a more capable entry-level refractor.
How RecommendedOptics picked: we started from the 119 most-reviewed refractor telescope listings in our retail dataset, removed duplicates, accessories and off-category products, and 82 qualified. This product is one of 15 from that pool chosen for a full review. Our scores blend buyer satisfaction (60%), price position against comparable products (25%) and rating volume (15%). Specifications come from manufacturer listings and ratings from verified Amazon buyer reviews (data checked August 2026).
The Short Answer on the TourStar Pro 90
Best for: you need to see lunar craters and Jupiter’s moons clearly but want a more portable setup than a large 100mm+ aperture refractor.
The SpectrumOI TourStar Pro 90 AZ is a strong choice at $188.59.
- Pro: The 90mm aperture clears the 70mm threshold required to resolve lunar craters and Jupiter’s moons.
- Pro: It includes a 2X Barlow Lens and three glass eyepieces (4mm, 10mm, and 20mm) for versatile magnification.
- Pro: The 660mm focal length provides a balanced reach for planetary observation.
- Con: The lack of an Apochromatic (ED) glass specification means you may see some purple fringing on bright objects.
- Con: The AZ mount lacks the tracking capabilities of an Equatorial (EQ) mount for long-exposure photography.
Price assessment: At $188.59, this is a fair price for a 90mm refractor that includes a 2X Barlow and multiple glass eyepieces.
RecommendedOptics score: 7/10 (data-driven – see “How we picked” above)
If you need a different mount style, see how the Gskyer Refractor Telescope performs in our analysis.
New owners should consult our guide to the best refractor telescope for adults before making a final purchase.
The Numbers on the Spec Sheet
| Aperture | 90mm |
| Focal Length | 660mm |
| Optical Coating | Fully Multi Layer coated glass with Magnesium Difluoride |
| Included Eyepieces | 4mm (Aspherical), 10mm, and 20mm |
| Barlow Lens | 2X |
| Weight | 15.92 pounds |
| Dimensions | 40 x 40 x 48 inches |
The 90mm aperture clears the 70mm threshold required to resolve lunar craters and Jupiter’s moons clearly.
Performance in Practical Terms
Magnesium Difluoride Optical Coatings
The TourStar Pro 90 uses Magnesium Difluoride coatings to minimize color fringing and improve light transmission. These coatings help you achieve sharper images of bright objects like the Moon and Jupiter by reducing the chromatic aberration common in standard glass.
Aspherical Eyepiece Clarity
The included 4mm aspherical eyepiece allows for higher magnification with reduced spherical aberration. You can use the 4mm, 10mm, and 20mm glass eyepieces to transition from wide-field views of star clusters to closer looks at planetary surfaces.
Smartphone Integration
Smartphone integration is supported via an included adapter, allowing you to capture photos of the night sky directly to your mobile device. This setup enables you to share observations without needing a separate dedicated camera system.
Is the mount stable enough to keep the image steady when I’m zoomed in on the moon?
The TourStar Pro 90 features an AZ (Alt-Azimuth) mount which allows for simple up-down and left-right adjustments. To ensure the image stays steady when you are zoomed in, check the tripod’s weight capacity and height in your specific environment, as the provided data does not specify the maximum weight limit or tripod stability ratings.
How the TourStar Pro 90 Compares to Alternatives
The TourStar Pro 90 offers a 90mm aperture, which clears the 70mm threshold required to resolve lunar craters and Jupiter’s moons clearly.
- The TourStar Pro 90 costs $0.29 less than the Celestron AstroMaster 90AZ Refractor Telescope.
- The TourStar Pro 90 holds a 4.2 rating, which is lower than the 4.4 rating of the Celestron AstroMaster 90AZ Refractor Telescope.
- The TourStar Pro 90 costs $1.4 less than the Orion StarBlast 90mm Altazimuth Refractor Telescope.
- The TourStar Pro 90 costs $2.37 more than the ZH-Wang MF40070 Refractor Telescope.
- The TourStar Pro 90 costs $7.4 less than the 114mm Refractor Telescope.
- The TourStar Pro 90 costs $8.6 more than the 70mm Aperture 700mm Focal Length Refractor Telescope.
How does the clarity of the 90mm glass compare to the bigger 100mm or 130mm models?
The 90mm aperture on the TourStar Pro 90 provides a balance of light-gathering power, but 100mm to 130mm refractor models offer more significant resolution for high-magnification viewing. You should check the specific focal length of the larger models you are considering to see how they compare to the 660mm focal length of the TourStar Pro 90.
If you prioritize the highest possible buyer rating, choose the Celestron AstroMaster 90AZ Refractor Telescope instead of the TourStar Pro 90.
Beginners can learn how a refractor telescope works by visiting our foundational guide.
What the Price Buys
The SpectrumOI TourStar Pro 90 AZ sits at the $188.59 mark, which is $1 above the $188 average of the similar refractor telescope products we compared. At this price point, you receive a 90mm aperture and a 660mm focal length, which clears the 70mm aperture threshold required to resolve lunar craters and Jupiter’s moons clearly. The inclusion of three glass eyepieces (4mm, 10mm, and 20mm) and a 2X Barlow lens means you do not need to purchase additional basic optics immediately to begin viewing. However, because the 2X Barlow lens is a standard accessory rather than a high-end component, you should check the specific manufacturer’s optical rating to ensure it maintains clarity at the maximum magnification limits.
This refractor telescope is the right buy if you want a complete starter kit that includes a 90mm aperture and a smartphone adapter for under $190. Since the 2X Barlow lens’s specific optical quality is not detailed in the specs, verify the manufacturer’s clarity rating if you plan to rely solely on it for high-magnification work. If your priority is avoiding the “hidden” cost of extra accessories, the included 4mm, 10mm, and 20mm eyepieces provide a versatile starting point that covers most common viewing needs.
Where this sits in the buyer data: Among the 44 products screened for this category, this one’s 4.2 rating places it #17, on 323 ratings – above the 37-rating median of that group, so the average rests on more feedback than most of its comparables. On price it undercuts 35 of them.
Questions Buyers Ask About the TourStar Pro 90
How much weight can the tripod actually hold before it starts to wobble?
The TourStar Pro 90 is designed for a 90mm aperture, but the specific weight capacity of the included tripod is not listed in the technical specifications. You should check the manufacturer’s weight limit for the included mount to ensure it supports your specific camera or accessory setup.
Does the smartphone adapter actually stay in focus or is it just a holder?
The included smartphone adapter allows you to use the TourStar Pro 90 as a smartphone telescope. Because the data does not specify the adapter’s focal distance or mounting position, you should verify if the phone’s sensor can reach the required focus point for your specific device model.
Is the SpectrumOI TourStar Pro 90 good for viewing planets?
The TourStar Pro 90 is suited for viewing Jupiter and Mars due to its 90mm aperture. This size clears the 70mm aperture threshold required to resolve lunar craters and Jupiter’s moons clearly.
What is the maximum magnification for the SpectrumOI TourStar Pro 90?
The TourStar Pro 90 reaches higher magnification levels when paired with the included 2X Barlow lens. You should verify the specific magnification limits provided by the manufacturer to ensure the image remains clear at high power.
Is the TourStar Pro 90 Right for You?
The TourStar Pro 90 suits 5 kinds of buyer and is the wrong choice for 4 jobs, listed below with the reason for each.
Who the TourStar Pro 90 is for, and what it does well
Who the TourStar Pro 90 suits
- Parents of children interested in astronomy — the ‘telescope for kids’ designation and included accessories make it an accessible entry point
- High school science students — the 90mm aperture and 660mm focal length provide clear enough views of Mars and Jupiter for classroom projects
- Social media content creators — the included smartphone adapter allows for easy capturing of celestial images for sharing
- Beginner backyard astronomers — the 4mm, 10mm, and 20mm eyepieces provide a range of magnifications suitable for initial learning
- Budget-conscious hobbyists — the $188.59 price point offers multi-coated glass optics without a professional-grade price tag
What the TourStar Pro 90 handles well
- Lunar crater observation — the 90mm aperture and 660mm focal length provide sufficient detail for the Moon
- Planetary viewing — the ‘telescopio profesional para ver planetas’ designation and 2X Barlow lens support high-magnification views
- Astrophotography for social media — the included smartphone adapter allows for direct mobile capture
- Star hopping — the 20mm eyepiece provides a wider field of view for locating constellations
- High-clarity viewing — the Magnesium Difluoride multi-layer coatings ensure sharp images
What the TourStar Pro 90 is the wrong choice for
- Deep-space nebula photography — the 90mm aperture is too small to capture faint, distant galaxies with high detail
- Professional long-exposure astrophotography — the lack of a motorized tracking mount limits use to stationary objects
- Ultra-high magnification of distant moons — the 90mm aperture limits the maximum usable magnification before the image blurs
- Observing very dim galaxies — the 660mm focal length and 90mm aperture are optimized for bright objects like the Moon and planets
What to budget alongside the TourStar Pro 90, and what to skip
Worth buying at the same time
- Sturdy tripod — necessary to stabilize the 660mm focal length telescope for steady viewing
- Moon filter — needed to reduce the glare of the Moon when using the high-magnification 4mm eyepiece
- Astronomy guidebook — needed to identify the celestial wonders mentioned in the product description
- Protective carrying case — needed to transport the glass optics and included accessories safely
What you can skip
- Additional 2X Barlow lens — the product already includes an astonishing 2X Barlow Lens
- Basic 10mm eyepiece — the telescope already includes a 10mm eyepiece in the box
- Basic 20mm eyepiece — the telescope already includes a 20mm eyepiece in the box
- Basic 4mm eyepiece — the telescope already includes a 4mm aspherical eyepiece in the box
Where to Buy the TourStar Pro 90
These retailers sell Refractor Telescope generally – we do not track which of them has this particular model in stock, so check availability and the current price with the retailer before making a trip.
- Target (online and physical stores) — convenient in-store pickup for basic starter scopes
- B&H Photo Video (online only) — reliable shipping and professional photography/optics expertise
- High Point Scientific (online only) — specialist retailer with expert staff and technical advice
- Orion Optics (online only) — specialist retailer with a wide range of dedicated astronomy gear
- Amazon (online only) — wide selection of entry-level and mid-range brands
- Walmart (online and physical stores) — physical availability for common beginner models
Final Verdict on the TourStar Pro 90
If you need a telescope that exceeds the 70mm aperture threshold for clear lunar craters and Jupiter’s moons, the SpectrumOI TourStar Pro 90 AZ is a strong choice at around $188.59.
The TourStar Pro 90 provides a 90mm aperture and 660mm focal length, supported by a 4.2 rating from 323 buyers to validate its performance for beginners.
Skip it if: you require an apochromatic (ED) lens to eliminate color fringing, as this model uses standard multi-coated glass optics.
The rest of our Refractor guides
- The Refractor Telescopes That Work Best for Travel
- Which 90mm Refractor Telescope Is Best for Astronomy?
- Best 80mm Refractor Telescope for Astronomy
- 70mm Refractor Telescopes for Astronomy Compared
- Choosing the Best Refractor Telescope for Adults
- The Refractor Telescopes That Work Best for Portable Use