ZWO Seestar S50 vs. Seestar S30: Which Smart Telescope is Right for Your Stargazing Adventure?

The ZWO Seestar series is bringing the night sky closer for both beginners and enthusiasts by making astrophotography more accessible than ever. With the Seestar S50 already a popular choice and the Seestar S30 joining the lineup, each smart telescope offers unique strengths. Here’s a closer look to help you decide which one best suits your style.

Design and Portability: S30 for Grab-and-Go, S50 for Stability

If portability is top of mind, the Seestar S30 smart telescope is a great option. Weighing just 1.65 kg, it’s about as light as a small water bottle, so you can take it anywhere. Its compact frame is perfect for travelers, hikers, or anyone working with limited space. The Seestar S30 also features a dual-lens system with a main telephoto lens for close-up views and a wide-angle lens for broader sky scenes, giving users flexibility for both detailed and expansive imaging without changing equipment.

The Seestar S50 is a bit heftier at around 3 kg but still compact enough for easy transport (Personally flown with mine in hand luggage). This added weight gives it a bit more stability, which can come in handy for longer stargazing sessions. If you’re planning to set up in one spot and settle in for the night, this extra stability might make the S50 a more comfortable choice.

Aperture, Focal Ratio, and Field of View: Bringing Clarity to the Night Sky
If you’re weighing up the Seestar S30 and S50, it’s useful to understand how features like aperture, focal ratio, and focal length come together to shape your view of the night sky. Don’t worry—while these terms may sound technical, they’re easy to grasp with a quick breakdown.

Aperture and Focal Ratio: Aperture refers to the diameter of the lens or mirror that collects light. In this case, the S30 has a 30mm aperture, while the S50 offers a larger 50mm. A bigger aperture means more light collection, resulting in brighter, clearer images, especially for dim objects.

The focal ratio, or f/number, is calculated by dividing the focal length by the aperture. Both models have a focal ratio of f/5, meaning they can gather light efficiently and produce bright images quickly. This f/5 ratio is considered “fast,” making these telescopes ideal for wide-field astrophotography where you want to capture large sections of the night sky—think star clusters and nebulae.

Focal Length and Field of View: The telescope’s field of view—the amount of sky you see in a single shot—is more influenced by focal length. The S30 has a shorter focal length of 150mm, giving it a broad field of view that’s perfect for capturing large portions of the sky in one go. On the other hand, the S50 has a longer focal length of 250mm, narrowing the field of view a bit, which is helpful for focusing on details in specific objects like the Moon or galaxies.

In summary, the S30’s combination of a 150mm focal length, 30mm aperture, and dual-lens system provides bright, wide views ideal for sweeping sky scenes. Meanwhile, the S50, with its 250mm focal length and larger 50mm aperture, pulls in more light and detail, making it suitable for both wide fields and close-ups of individual celestial objects.

Built-In Filters and Imaging Sensors

Both the Seestar S30 and S50 come with built-in filters and quality sensors, each tailored slightly differently:

• Seestar S30: Uses the Sony IMX662 sensor, known for its low noise and high sensitivity, which is helpful for capturing sharp images even with ambient light. The S30 also includes three filters—a dark field filter, UV/IR cut filter, and a dual-band light pollution filter—that enhance clarity by reducing urban light pollution. The dual-band filter isolates Oxygen III (OIII) and Hydrogen-alpha (Hα) wavelengths, which is especially useful when photographing nebulae and other emission-rich objects.

• Seestar S50: Equipped with the Sony IMX462 sensor, the S50 also performs well in low light and captures fine details thanks to its larger aperture. This model includes a a dark field filter, UV/IR cut filter, and the same dual-band light pollution filter found in the S30, designed to block specific wavelengths for clearer images in light-polluted areas. Users can switch filters on via the app, providing flexibility based on viewing targets and conditions.

App Functionality

Both models connect seamlessly to the Seestar app, providing an intuitive experience for everything from object selection to image capture. Designed to simplify astrophotography for all users, the app continues to evolve—ZWO regularly adds powerful new features at no extra cost.

Key features now include:

• One-Touch Imaging:
  Both the S30 and S50 allow you to capture images of planets, galaxies, and nebulae with a single tap. This removes the complexity of adjusting exposure or gain manually—perfect for beginners.
• Mosaic Mode (Framing):
  The app’s Framing tool lets you capture large celestial objects in high resolution by automatically stitching multiple images. Ideal for wide targets like the Andromeda Galaxy or Milky Way starfields.
• Scene Selection:
  Choose from presets tailored to planets, deep-sky objects, or the Moon. The app adjusts settings automatically to optimise your results for each type of target.
• AI-Enhanced Image Quality:
  Real-time processing and noise reduction help stabilise images and boost clarity—especially useful for wide fields on the S30 and planetary detail on the S50.

New in 2025

• Equatorial (EQ) Mode now with 60s Exposures:
  Mount your Seestar on a compatible star tracker to unlock EQ Mode, allowing up to 60-second guided subs. This captures finer detail in faint nebulae and star clusters without overexposing.
• Flat-Frame Capture:
  You can now create and apply calibration flats directly within the app, reducing vignetting and removing dust artefacts from your final stacked images—no extra software required.
• RAW in Scenery Mode:
  For users who want full post-processing control, Scenery Mode now includes 16-bit RAW (FITS) capture alongside standard JPEG, preserving maximum image data.

With features like these—and a steady stream of free upgrades—the Seestar app delivers a flexible imaging experience that grows with you. Whether you're capturing your first Moon shot or diving into guided deep-sky imaging, it's built to support every step of your astrophotography journey.

So, Which Smart Telescope Should You Choose?

If you’re looking for a lightweight, wide-field smart telescope that’s easy to take on the go, the Seestar S30 is a solid choice. Its compact design and smart features make it convenient for outdoor adventures, and it’s ideal for capturing large, sweeping views of the night sky.

On the other hand, if you’re interested in capturing finer details with a higher light-gathering ability the Seestar S50 smart telescope could be the better fit. Its 250mm focal length, larger aperture, and manual filter options make it a versatile choice for both focused observations and adaptable image enhancement in different environments.

Both the Seestar S50 and S30 offer high-quality, accessible stargazing experiences. With a consistent app interface across both models, ZWO’s smart telescope series makes it easy to dive into the night sky, whether you’re after broad views or more detailed exploration. Both deliver impressive performance for their price, offering excellent value for beginners and experienced stargazers alike. Stay tuned as we update this blog with further information, real-world reviews, and app enhancements to keep you informed on the latest developments.

Specifications comparison Chart

The following chart will help you compare the specs directly with more details below the table.

Note: This comparison is based on information provided by the manufacturer. Real-world performance and user experiences may vary. We’ll update this blog with additional insights as more hands-on reviews and comparisons become available.

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