ZWO Seestar S50/S30 Smart Telescopes

Recently, at our April 2024 meeting, FAS member Dr. Bill Rankin gave a most interesting talk about the ZWO Seestar S50 telescope.

Two days after Bill’s talk, the folks at BBC Sky at Night Magazine published a review of the Seestar S50. It is getting a lot of hype lately. So, we thought it would be appropriate to post something on the FAS website about this telescope with some information and a few reviews found online.

Credit: ZWO

Here are a few images from Bill’s Seestar S50 (Credit: Dr. William Rankin). The S50 comes with a solar filter. FAS member Betty Allison took a couple images of the April 8th solar eclipse with her Seestar S50 (Credit: Betty Allison).

In November 2024, ZWO launched the Seestar S30 – a smaller version of the Seestar S50. At a lower price, it has a smaller lens (30 mm), but one with a wider field of view.

We have several more images and resources below as well as some helpful hints on how to use your Seestar.

For more on astrophotography including other “smart” telescope options, see our Astrophotography Page. You can also find a summary of the different types of deep-sky objects on our website.

Please note that FAS does not necessarily endorse or recommend this or any other specific telescope or accessory. We simply provide information that might be interesting and useful for the public.

More Sample Images

FAS member Bruce Gavett has taken several images over the last few months with his Seestar S50. (Credit: Bruce Gavett).

The easiest target was the Moon, highlighted by the August 2024 blue supermoon. Note how clear you can see the rays coming from Tyco. And Copernicus is easy to find near the center. The Sun presents a similar target, although you must use the solar filter provided by ZWO.

Open star clusters can be found and imaged in even light polluted areas with only a short (3 minute or so) set of exposures. However, a longer exposure time will bring out more of the adjacent stars.

Globular clusters were the same – led, of course, by the Hercules cluster (M13) and M15 in Pegasus. However, a longer exposure time does bring out more details and more stars.

Planetary Nebula are easy targets, although, a few, such as the Helix nebula required a much longer set of exposures. Supernovae remnants are a bit more difficult and also require a longer series of exposures, but the Veil nebula, in particular, is worth the effort.

Emission nebulae are a bit more challenging, particularly from a light polluted area, but they can be viewed using longer sets of exposures and with the dual band filter. Larger nebula such as the North American and California nebulae are even more challenging because they exceed the Seestar S50’s field of view.

Galaxies are the most difficult. Light pollution does limit what you can see, therefore, a dark location is best.

A Few Reviews (S50)

A Few Resources (S50)

A Few Videos (S50)

A Few References and Reviews (S30)

Where to buy, Apps and Manuals

Accessories

Seestar Workflow

Here is a suggested workflow for taking and processing images with your SeeStar.

  1. Make sure the option to save individual frames is turned on.
  2. Take 10 sec (or maybe 20 sec) frames for 15 minutes or longer.
  3. Re-stack the image subs (frames) using Seestar’s Deep Sky Stack.
  4. Run Seestar’s AI Denoise routine to clean up your stacked image.
  5. Save your final image.

If you have a bit more experience, here is a more advanced workflow.

  1. Make sure the option to save individual frames is turned on.
  2. Take 10 sec (or maybe 20 sec) frames for 15 minutes or longer.
  3. Connect your Seestar to your computer using a usb c cable.
  4. Copy your saved sub frames from Seestar’s MyWorks folder to your computer.
  5. Restack your sub frames using a 3rd party package such as Siril.
  6. Process your image(s) using a 3rd party package such as Siril.

SeeStar Image Storage

Images taken by your Seestar are stored in its internal memory. You have 65GB (less the operating system) available. To access these images, go to the main screen and choose My Albums. This will take you to a screen that shows you the images you have saved to your device (e.g., iPad or iPhone) and Seestar, the images stored in your Seestar. Select Seestar and you will see the final images along with the “sub_s”, which are the 10 second snap shots.

You can select any of these images and download them to your device. You can also go back to the home screen and choose Deep Sky Sacker to re-stack the available sub_s.

Re-stack Images using Deep Sky Stack

Some of your stacked images will end up with dark corners due to the rotation of Seestar’s field of view over time. There are also times when lines appear due to satellites passing through and, from time to time, trees get in the way.

Make sure you are saving your individual sub frames to Seestar’s My Album and then go back and re-stack them using Seestar’s Deep Sky Stack. Be sure to remove the sub frames with the trees and satellite tracks before re-stacking.

The final image usually looks much better.

Mosaic Mode

In October 2024, ZWO added a “mosaic“ mode. This allows one to take images that are offset from the previous vertical only orientation or to expand the view to capture wider field objects. Note that when using the mosaic mode, you do not have to save individual sub frames – they don’t re-stack well.

AI Denoise

(December 2024) ZWO has just added an AI Denoise feature. When viewing the live image on your screen or an image stored in your Seestar’s My Album, click the denoise button and your Seestar will apply an AI algorithm and clean the image up. You will then have the option of saving the resulting image to your tablet or phone. The changes to your images might be subtle, but in most cases they are noticeable (see before and after below).

Before AI Denoise

After AI Denoise

Process Images in 3rd party software

If you connect your Seestar to your computer with a usb c cable, you can export the individual sub frames (in fit format) for stacking and processing in other software packages such as Siril. Make sure to first remove the “bad” sub frames as noted above. Then copy the sub frames from Seestar’s MyWorks folder to your computer.

The images below were processed in Siril following a basic workflow. They still have a brownish background and a fair amount of background noise.

Using a more advanced (and complex) workflow in Siril will address these issues. (more to come here).

Images processed in Siril (C. Richard et al., Journal of Open Source Software, 2024, 9(102), 7242. DOI: 10.21105/joss.07242)

Summary Illustrating the Entire Process

Here is a summary set of images taking you through the entire process: Original Stacked Image, Original Stacked Image with AI Denoise, Re-stacked Image, Re-stacked Image with AI Denoise, Siril Image with auto stretch, and Siril Image with manual stretch.

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