Seestar S50 self-help group

[Dr Paul Leyland]

Any other Seestar S50 users here, especially newbies who could swap problems and solutions?

A S50 turned up a couple of days ago and although it sort of works, I hit problems.

Managed to take a “scenery” image of the garden but have yet to take anything of astronomical interest.

Paul

[Lars Lindhard]

Hi Paul

I don’t think I am a newbie anymore but if I can help please let me know.

[Dr Diane Clarke]

I am currently using an S50,& have some exp using same, what problems have you encountered ?

[Dr Paul Leyland]

Thanks both.

I have a series of questions but will deal with them one at a time to help reduce confusion. Further, please note that I know very little about this system, in part because of the woefully limited documentation that ZWO provides, so may have some completely false assumptions and preconceptions.

First concerns set-up. I thought that the S50 would use Bluetooth to communicate with an Android phone. At initialization time the S50 states “Need bluetooth access to search Seestar nearby” and it is necessary to set the phone’s Wifi connection to the 10.0.0.0/8 local network created by the S50. Connection then proceeds satisfactorily but, of course, the phone no longer has access to the internet — seriously crippling other important features.

I have tried everything I can think of to configure the phone to allow the use of Bluetooth, without success. The phone will happily pair with other devices, such as a laptop so much is clearly working.

Any suggestions? If it helps, the Seestar firmware is V2.95

[Lars Lindhard]

I use Iphone and I don’t know if the system is similar on Adroid, but I can connect to the Seestar through Seestar’s wifi and still have access to the internet.

If you observe near your house with the Seestar, you can use station mode, where the Seestar connects to your internet source and you can have connection to it from your phone from anywhere

[Dr Diane Clarke]

With regard to the Bluetooth not connecting, have you pushed the reset & then tried to re-connect ?

[Dr Paul Leyland]

Thanks Diane,

Yes, I have, many times.

[Dr Paul Leyland]

Thanks Lars,

I have now set it up in station mode and will see how I get on.

[Dr Paul Leyland]

OK, so far, so good. A brief gap in the clouds allowed an image of Albireo to be taken. Only four images were successful, it seems, out of an imaging session which lasted two or three minutes, but lets let that go for a moment.

The only way I could find to get them off the phone was to connect a USB cable and use the file browser to copy them to the local disk. Again, lets let that go for a moment.

There were 5 files, corresponding to four 10-second subs and a stack of four. All the files are in JPEG format and the stack is included here.

Next question: I would like to do precision photometry, so how can raw FITS files be created by the Seestar app in a place which is generally accessible? The JPEG shows clear artifacts which I would prefer not to have imposed. AIUI, the raw images can be saved and transferred.

Thanks,
Paul

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   1729368401626.jpg
   

[Alex Pratt]

Hi Paul,

I don’t have a Seestar but I found these presentations which might be of use, or at least of interest

https://www.youtube.com/watch?v=vMCf7nFMQmo

https://www.youtube.com/live/4BhlkOqo8cU?t=619s

Alex.

[Steve Knight]

Paul,

Have had a Seestar for about a year, very very happy. You have to set it to save individual frames internally. FITS files are stored in its internal memory in a sub folder. If it is in station mode you navigate to it on your network and download files. You can do this as it’s acquiring data.

Steve

[Dr Paul Leyland]

Thanks Steve.

I found that connecting the USB cable to a Windows PC makes the FITS files available as an external storage device. It doesn’t (yet) work on a Linux box.

Initial experiments with station mode were not very productive but as I don’t really know what I am doing, perhaps that may be expected.

TFM is woefully inadequate and saving individual frames is presently beyond my ability. That will almost certainly change fairly soon.

Paul

[Dr Diane Clarke]

When connecting to USB 3 there is a faster connection / transfer rate between the S50 & the P.C. / Laptop, also you can save all fits files from within the S50 app settings. go to “Advanced Features” then select “Save Each Frame”.

[Dr Paul Leyland]

Thanks Diane. Turns out that I had already done that without noticing. Once station mode was started properly a file browser on the Linux box could also see the internal storage and was able to copy the individual frames.

Also: wrt Bluetooth I found that giving the app permission to chane system setting was necessary. Not at all sure that is wise from a security point of view so may disable it again and rely on station mode for access within range of the wifi and USB cable when I am on the road.

• This reply was modified 2 weeks, 2 days ago by Dr Paul Leyland.

[Dr Paul Leyland]

Now that I seem to have control over most of the needed functionality, I turn to image quality.

Only one object has been imaged so far, Albireo or β Cyg. It was taken on a poor night but during the only clear spell so far available. Bear in mind that thin haze may have been present. The image shown is the green channel of the 40s stacked image. β Cyg B shows a very obvious ring around it, measured at a radius of 14 arcsec from the center of the stellar image. Other fainter stars show similar rings at 11-14 arcseconds radius. The radius Airy disk of a 50mm aperture in green light is 2.4 arcsec (and pretty much the same for FWHM) and the first bright diffraction ring should be at 5.4 arcsec assuming I calculated correctly. Much less than 14 arcsec anyway. The image scale is 2.37 arcsec/pix according to astronomy.net; this is a good match to the Airy disk size.

Any ideas what may be causing this? Stray reflections is one possibility that comes to mind, as is rather bad spherical aberration.

I will take more images on properly clear nights to see whether the effect is reproducible but I would be interested to learn whether other Seestar users experience the same effects. If not, perhaps it should be fixed / or exchanged under warranty.

Here’s the image which shows the ring.

• This reply was modified 2 weeks, 2 days ago by Dr Paul Leyland. Reason: Add image scale information

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   Albireo.png
   

[Dr Diane Clarke]

Paul I have also imaged Albero, when at a recent outreach event, this is a jpeg generated by the s50 from a stack of 103 10sec frames, I did have the dew heater active & a dew shield fitted to the front of the s50.

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   Stacked_103_Albireo_10.0s_IRCUT_20240927-204808A.jpg
   

[Dr Paul Leyland]

Thanks. It looks like a generic problem as your image also shows rings around the brighter stars.

Not a deal breaker as photometry is very tolerant of slightly blurred and/or trailed images and I want to do science and not artwork.

Anyway, such artefacts can often be cleaned up in post-processing.

[Dr Diane Clarke]

Afternoon All,

I have just found out V2.01 is out –

V2.1 supports what ZWO used to call mosaic now calls it framing mode. Available for iOS now, Not there for Android but should be very soon.

Diane.

[Dr Paul Leyland]

Dr Paul Leyland wrote:

Thanks. It looks like a generic problem as your image also shows rings around the brighter stars.

Not a deal breaker as photometry is very tolerant of slightly blurred and/or trailed images and I want to do science and not artwork.

Anyway, such artefacts can often be cleaned up in post-processing.

It appears that my image is not properly focused. It should be obvious, but wasn’t, that auto-focus should be run every time before taking images. One day I will print a Bahtinov mask to see how well AF works. Reports are that it is pretty good.

[Dr Paul Leyland]

I’m curious. The current Android version is labelled V2.95 which to me is a larger number than 2.1

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