ZWO Seestar 50

[powerlord]

2 hours ago, Cosmic Geoff said:

I received the SS50 a few days ago and on Friday I was able to take it on a dark skies weekend and give it its 'first light'. 

First impressions are that it is extremely easy to use, except that the app is not that easy to use, and in total darkness it is impossible to see where the little black device is pointing itself - whether somebody is stood in front of it, or if it is pointing at a tree. 

The aiming process (entirely automatic) is not that quick and can take a minute or more while the device plate-solves and re-aims.   One has to initiate the actual stacked image taking manually.   Once taken, the images look good on the smartphone and if you have setup with icloud will copy to your image processing computer without further intervention.

Here, I found that an increase in contrast brings up nebulae in the iphone image nicely.

Images are also stored in the SS50 itself and this is a different story. First, these are not the same images as sent to the smartphone. There is a low-resolution jpg which is essentially a thumbnail, and a high-resolution FITS file.

A big GOTCHA here for anyone who is used to using Sharpcap for live-stacking and saving a file.  This is apparently a different variety of FITs file and needs to be stacked in Deep Sky Stacker or Siril, before processing in (e.g.) GIMP.   It took me a while to realise this, following a search online. So I downloaded and installed Siril, and tried to follow an instructional video for processing SS50 FITS that I found on Youtube.

Turns out after further head-scratching that this involves a script file that has to be downloaded separately because it's not in my Siril.  Could not find script, and gave up.

TBF I'm not impressed with this.  It's really easy for any newbie to use this device, but if you want to process the saved images, you are expected to instantly transform into Image Processing Expert?

fancy uploading a zip of fits for us to play with here ?

It does sound like they are just regular fits files if they work in Siril, etc. Never used sharpcap. Siril isn't very user friendly for sure.

When did you order if you don't mind me asking ? I ordered the 2nd day it was announced and mine is still 'processing' 😞

 

[Elp]

2 hours ago, Cosmic Geoff said:

Siril

To stack you follow the tabs on the RHS in order, for simplicity I won't include the calibration step but it's easy to load a master dark, flat at this process:

1. "Conversion" tab, load your lights by pressing the plus button and navigate to where your light images are, select and add.

2. Give it a sequence name under "destination" (Siril in my workflow works best when you assign each set of images you're processing a sequence name and changing the drop down box next to it from fits images to fits sequence), the reason is in the "sequence" tab the active sequence is the one being processed at the time and is much easier to manage than a lot of fits files. Every time Siril does an operation on a sequence it will update the sequence to a new sequence name by the name you provide so the process is non destructive.

3. Check the debayer option (as it's colour data) and press the convert button (I usually debayer at the calibration stage). The console will become active telling you what it's doing and when it's complete. There's also a blue progress bar underneath showing you the live progress.

4. As I'm skipping calibration next is the "registration" tab. Can leave all on default, registration method Global Star Alignment usually works well. Click the Go register button and it will analyse your stars in each image and provide a quality graph under the "plot" tab if you're interested (can go much more in depth).

5. "Stacking" tab, you can leave everything default, under image rejection I normally change from all to weighted FWHM and set it to 80-90pc, so the remaining poor star images will be rejected. Press the start stacking button.

6. Once done your stack is visible in the main window (it updates after every process operation), for the sake of previewing it you can change under the image the drop-down menu from "linear" which is by default what the data is still in, to "asihn/autostretch", note this only changes the preview, the image is still in linear until you start post processing further. You can save the current linear file by pressing the download icon next to save and if you want to save as tif change the extension after the filename. Siril will automatically save the stack as a fit file in the default Siril processing directory you give it, under windows I think it defaults to the "pictures" folder. Note once done you'll want to delete all the files Siril generates in this folder as it'll eat up space over time as well as be confusing if you end up doing multiple projects without clearing it.

7. On the linear stack for a very basic process of stretching you can go to "image processing", "histogram transformation" and bring up the black point slider closer to the left of your histogram peak, and the mid point to the right of the peak and press apply. Do this at least 6 times or more to bring the faint stuff out and resave the image once done.

Siril seems complicated but it really isn't. It's laid out in a logical way and why I always advocate to learn to process step by step rather than rely on scripts as you learn to troubleshoot your data along the way.

[Cosmic Geoff]

I have established by using NASA's FV fits viewer that the SS50's FITS files definitely contain multiple images - the number varies depending which file I checked. They differ from Sharpcap's stacked FITS files.

As for how to unbundle and stack them, I still don't see how.

[happy-kat]

ZWO has a fits viewer in their desktop asi studio

[powerlord]

4 hours ago, Cosmic Geoff said:

I have established by using NASA's FV fits viewer that the SS50's FITS files definitely contain multiple images - the number varies depending which file I checked. They differ from Sharpcap's stacked FITS files.

As for how to unbundle and stack them, I still don't see how.

lots of fits do - thumbnails, etc. it's part of the format. you shouldn't need to unbundle them to stack them. fits is a very broad 'standard' though. does siril open them natively ? if it doesn't sirilic is the easiest automatic conversion and stacking app (google it). If it does, just watch a youtube video on stacking and do one with no flats/darks/etc to start - no need for scripts - can be done straight in siril.

[DaveL59]

Now received the mask from ebay, looks well made. I note there's a slight dimple in the rim that fits into the S50, possibly to get it to snug fit and hold in position.

Also found my x1.4 tele/wide adaptors which are Tokina ones. Quite light so may carry easily enough on the S50, 49mm thread and a 52mm adaptor, so with your filter ring I'd sort a 49-48 step-down to fit it, perhaps.

In case useful for verification, diameter across with the nib. Depth of the section going into the S50 opening 4.7mm.

 

[M40]

Using a mask with the seestar, where there is no manual focus unless I have missed it, I presume we goto a bright star insert the mask, then autofocus? What do you think.

[powerlord]

5 hours ago, DaveL59 said:

Now received the mask from ebay, looks well made. I note there's a slight dimple in the rim that fits into the S50, possibly to get it to snug fit and hold in position.

Also found my x1.4 tele/wide adaptors which are Tokina ones. Quite light so may carry easily enough on the S50, 49mm thread and a 52mm adaptor, so with your filter ring I'd sort a 49-48 step-down to fit it, perhaps.

In case useful for verification, diameter across with the nib. Depth of the section going into the S50 opening 4.7mm.

 

thanks, yeh that dimple is just an artifact of 3d printing where the cylinder lines start each time - pretty normal.

stu

[powerlord]

Just now, M40 said:

Using a mask with the seestar, where there is no manual focus unless I have missed it, I presume we goto a bright star insert the mask, then autofocus? What do you think.

no, the idea is you let it autofocus as normal, but at the end, you pop in the mask and you will be able to verify if the routine worked properly or if it's out of focus and you need to try it again.

later when manual focus is added you can keep it on while manually focusing.

it won't autofocus with the mask on - it'll just confuse it.

stu

[M40]

1 minute ago, powerlord said:

it won't autofocus with the mask on - it'll just confuse it.

Ta muchly, I do like the sound of confusing a computer though 🤣

[DaveL59]

1 hour ago, M40 said:

Using a mask with the seestar, where there is no manual focus unless I have missed it, I presume we goto a bright star insert the mask, then autofocus? What do you think.

seems so from the videos, at lest it'll confirm focus is good. MF may come along in a firmware update which would make the mask more useful.

[Cosmic Geoff]

On 19/09/2023 at 16:17, powerlord said:

When did you order if you don't mind me asking ? I ordered the 2nd day it was announced and mine is still 'processing' 😞

I ordered mine on 17 April.

I am still trying to figure out what's what with the FITS files.  Some testers apparently received units which (like mine) produced a composite FITS file which did not need stacking.

[powerlord]

post a few here - you have an audience of knowledgeable folk (not including myself here!)

[DaveL59]

Another updated review, seems MF may be there in the update he's installed.

 

[LDW1]

I have probably read this some time but what is the minimum temperature that the SS can effectively be used !  Below freezing, if so how much ?

[StevieDvd]

8 hours ago, LDW1 said:

I have probably read this some time but what is the minimum temperature that the SS can effectively be used !  Below freezing, if so how much ?

All the specifications are on https://astronomy-imaging-camera.com/product/zwo-seestar

[LDW1]

4 hours ago, StevieDvd said:

All the specifications are on https://astronomy-imaging-camera.com/product/zwo-seestar

So it is all hidden in one line in the spec. block ie recommended 0-40° C !  I would really have thought that would be an important factor / feature to be clearly pointed out because many of us new owners will / do live in some pretty cold climates when, say, Orion, the Pleides are at their best !  Maybe even give, very clearly, the reason or the hazards if using it below 0° other than maybe fast battery drain, I guess maybe the powers that be don't really care about that end, lol ?

[Carbon Brush]

The cost conscious markets (including amateur astronomy) use commercial grade electronics, which is sometime only specced to 0C.
However, in practice it does continue to work at lower temperatures.
Looking at the many discussions discussions on various mount operation in the cold, grease thickening is mentioned more than freezing electronics.

The most temperature sensitive part of most amateur astro kit is the battery.
ZWO say the device can be used to -10C, which is a reasonable limit for lithium discharge. Without knowing the exact spec of the cells, I cannot comment further.
Note charging temperature for lithium is more restrictive. However, the charger control should look after this for you by disabling charge if too hot or too cold.
ZWO say charging is allowed from 0C to 40C.

HTH, David.

[LDW1]

22 minutes ago, Carbon Brush said:

The cost conscious markets (including amateur astronomy) use commercial grade electronics, which is sometime only specced to 0C.
However, in practice it does continue to work at lower temperatures.
Looking at the many discussions discussions on various mount operation in the cold, grease thickening is mentioned more than freezing electronics.

The most temperature sensitive part of most amateur astro kit is the battery.
ZWO say the device can be used to -10C, which is a reasonable limit for lithium discharge. Without knowing the exact spec of the cells, I cannot comment further.
Note charging temperature for lithium is more restrictive. However, the charger control should look after this for you by disabling charge if too hot or too cold.
ZWO say charging is allowed from 0C to 40C.

HTH, David.

You know that and I know that from many years of experience but there are very likely many new comers that don't and thus my post, my comments and the ensuing learning curve.  And you are correct Lithium batteries are not cold weather batteries in any appliance incl. portable work tools, etc. So why shouldn't the manufacturer give them a full, honest explanation, its important.

Edited September 24, 2023 by LDW1

[Cosmic Geoff]

ZWO have been issuing firmware upgrades for the Seestar 50, but nowhere on their site do they list the versions and what changes they introduce.  The instruction manual is also vague about the features.  Viewing the Youtube reports, one sees that some Seestars produce a composite FITS file while others (presumably with later firmware), appear to produce multiple FITS files.  One report claims that  late firmware delivers manual focus and the ability to connect to your home WiFi network (I'm not sure what this would do for you, other than dispensing with a cable to retrieve the FITS files).

We really need someone to compile an 'unofficial' user manual for the Seestar.

I upgraded the firmware on mine from v1.21 to v1.52, but without a sky to try it on it is not evident what difference, if any, this has made. This upgrade, incidentally, was accomplished in minutes with a few pokes of the finger. Compare that with the fooling around with cables, apps, and software libraries required to update the firmware on a Synta mount.   Celestron and Skywatcher had better watch their backs.

[Carbon Brush]

49 minutes ago, LDW1 said:

You know that and I know that from many years of experience but there are very likely many new comers that don't and thus my post, my comments and the ensuing learning curve.  And you are correct Lithium batteries are not cold weather batteries in any appliance incl. portable work tools, etc. So why shouldn't the manufacturer give them a full, honest explanation, its important.

Thanks for your comment. ZWO are not alone in providing little by way of specification and explanation.
A look at the vague statements made by many astro kit manufacturers shows ZWO are following a trend🤨
In terms of well understood and affordable rechargeable batteries, lithium is (in my view) the best choice for this application.

Lead acid offers far reduced performance sub zero. Historically we have got around this by putting astro leisure batteries in insulated boxes. Also by rating the leisure battery to be sometimes 10x the energy required in a night.
If you look at car batteries, there is a 'CCA' quoted. That is 'cold cranking amps' to help answer whether your car will start in winter.
The manufacturers well understand how lead acid performance falls of when cold.

Nickel cadmium (NiCd) and nickel metal hydride (NiMH) provide better performance than lead acid at low temperature.
But they still provide significantly reduced performance when cold.

Lithium rechargeable (in various varieties) do offer good performance with little performance degradation until they are so cold, they should not be used.
Actual temperatures and performance reduction vary between chemistry & manufacturer. But they are always better than the mature technologies.

A further big driver for choosing lithium is power per kilo of battery mass, and power per litre.
Figures vary, but if you think in terms of 3x lead acid performance, you aren't far out.
Would we be happy if the Seestar had an external power pack?

I have not had a close look inside a Seestar. I hope ZWO have included a thermistor in the battery pack to allow temperature measurement.
The signal from this device can prevent charging when too hot or too cold.
Further during discharge it can signal switch off outside of allowed operation temperature.
Typically lithium cells can be stored safely to 65C and hotter. But using them at elevated temperature does restrict life and can cause damage.

Off topic possibly but the battery discussion may have prompted thoughts.
Many of the lithium equipment fires we hear about result from incorrect charging regimes.
Part of the safety testing for lithium cell type approval involves putting an almost short circuit on a cell, and there not being a fire or leakage.
The ZWO manual indicates testing has been done, though I have not pursued the details.
If you buy lithium cells and batteries from fleabay or the long river company, this expensive and arduous work may not have done 😮
 

[LDW1]

47 minutes ago, Carbon Brush said:

Thanks for your comment. ZWO are not alone in providing little by way of specification and explanation.
A look at the vague statements made by many astro kit manufacturers shows ZWO are following a trend🤨
In terms of well understood and affordable rechargeable batteries, lithium is (in my view) the best choice for this application.

Lead acid offers far reduced performance sub zero. Historically we have got around this by putting astro leisure batteries in insulated boxes. Also by rating the leisure battery to be sometimes 10x the energy required in a night.
If you look at car batteries, there is a 'CCA' quoted. That is 'cold cranking amps' to help answer whether your car will start in winter.
The manufacturers well understand how lead acid performance falls of when cold.

Nickel cadmium (NiCd) and nickel metal hydride (NiMH) provide better performance than lead acid at low temperature.
But they still provide significantly reduced performance when cold.

Lithium rechargeable (in various varieties) do offer good performance with little performance degradation until they are so cold, they should not be used.
Actual temperatures and performance reduction vary between chemistry & manufacturer. But they are always better than the mature technologies.

A further big driver for choosing lithium is power per kilo of battery mass, and power per litre.
Figures vary, but if you think in terms of 3x lead acid performance, you aren't far out.
Would we be happy if the Seestar had an external power pack?

I have not had a close look inside a Seestar. I hope ZWO have included a thermistor in the battery pack to allow temperature measurement.
The signal from this device can prevent charging when too hot or too cold.
Further during discharge it can signal switch off outside of allowed operation temperature.
Typically lithium cells can be stored safely to 65C and hotter. But using them at elevated temperature does restrict life and can cause damage.

Off topic possibly but the battery discussion may have prompted thoughts.
Many of the lithium equipment fires we hear about result from incorrect charging regimes.
Part of the safety testing for lithium cell type approval involves putting an almost short circuit on a cell, and there not being a fire or leakage.
The ZWO manual indicates testing has been done, though I have not pursued the details.
If you buy lithium cells and batteries from fleabay or the long river company, this expensive and arduous work may not have done 😮
 

A huge explanation, I am well aware of the usability of various types of batteries. My only concern is a brief sentence or two, from the horses mouth, as to how workable or restrictive their batteries are at lower temperatures, just a heads up but not technical. Just to give the unaware astronomers of what to expect, maybe what to prepare for on those cold subfreezing nites when Orion is hanging high above their heads, it dosen't have to be rocket science, just a simple whats up. Too much to ask ?

[saac]

I thought it was pretty much common knowledge that all batteries suffer in performance regarding cold. Anybody into photography or any outdoor pursuit would surely be familiar with cold battery drain so I'm not sure that it is an issue that needs special highlighting as all battery powered equipment is affected similarly. 

Jim  

Edited September 24, 2023 by saac

[LDW1]

36 minutes ago, saac said:

I thought it was pretty much common knowledge that all batteries suffer in performance regarding cold. Anybody into photography or any outdoor pursuit would surely be familiar with cold battery drain so I'm not sure that it is an issue that needs special highlighting as all battery powered equipment is affected similarly. 

Jim  

Two things, first there may be many newcomers into this end of the hobby that don't realize or consider the issue and secondly a confirmation that the temperature range only pertains to battery related concerns, their performance and not other considerations.  You talk as if everyone buying into this new end are experienced whatevers ! As I mentioned a simple heads up for those new learners, a consideration, they won't all be scientifically minded geniuses like some, lol !  PS:  Why does a simple question asked always become a major problem, lol !

[LDW1]

50 minutes ago, saac said:

I thought it was pretty much common knowledge that all batteries suffer in performance regarding cold. Anybody into photography or any outdoor pursuit would surely be familiar with cold battery drain so I'm not sure that it is an issue that needs special highlighting as all battery powered equipment is affected similarly. 

Jim  

Did you ever think that maybe you thought wrong, lol ?