ZWO Seestar 50

[Elp]

51 minutes ago, cimh said:

enable me to stack images from more than one session

I don't have a SS but this is what I do. I stack every session generally the next day with calibration files, then to complete a project stack each stack (you have to go through the usual workflow, but no calibration, just register and stack). It's generally better to stack all frames in one go rather than stack stacks, but the above is easier to mentally manage, it's also a good way to check you didn't have issues during the session.

Regarding satellite trails, if you're using standard AP software to stack, use a Kappa Sigma rejection algorithm with a narrow or low outlier range (you'll have to test what works) and it'll remove the trails in the stack as long as you have a largish number of total subs.

Edited April 17 by Elp

[cimh]

3 hours ago, LaurenceT said:

Is it possible to show your Seestar in EQ mode or if not possible then a description of how you do it?

I am following Cuiv's excellent video https://youtu.be/QlLiK-wcLqk

My set up is in the image. You should think about a more robust tripod as the seestar is heavy and might topple the std one. You need a wedge like the skywatcher i have which you adjust to point to polaris. I have taped on a bit of 15mm copper pipe and this works really well. I always use the power bank which would probably power the Seestar with the dew heater all night. 

So compass calibrate the seestar.
Attach it to a reasonably level tripod
Sight polaris in the copper tube by manually adjusting the wedge.
Then use the app to point the Seestar somewhere overhead at some obvious stars and press the red photo button.
Seestar plate solves to work out what it is looking at and then does its 3 point calibration.
As soon as that has finished press cancel. That's it.

Then use the app as normal to select what you want to observe. 
Note: It is important to secure the shoe to the base of the seestar reasonably tight so that it does not loosen. This screw connection will be subjected to more torque because of the angle of the seestar. 

Hope that all makes sense.  

 

 

 

 

 

 

 

Edited April 17 by cimh
adding update

[Elp]

I believe there's the note in EQ they'll be the opposite pole restriction of seeing targets below a certain altitude due to the physical orientation.

[cimh]

37 minutes ago, Elp said:

I believe there's the note in EQ they'll be the opposite pole restriction of seeing targets below a certain altitude due to the physical orientation.

Yes, because Seestar is tilted then viewing towards the south becomes restricted as it thinks the horizon is much higher than it really is. I think polaris sinks lower in the sky as you move towards the equator in which case people living in lower latitudes will be more restricted as the seestar has to be tilted more to line up with Polaris.  I hope that's right

[Oortraged]

43 minutes ago, cimh said:

Yes, because Seestar is tilted then viewing towards the south becomes restricted as it thinks the horizon is much higher than it really is. I think polaris sinks lower in the sky as you move towards the equator in which case people living in lower latitudes will be more restricted as the seestar has to be tilted more to line up with Polaris.  I hope that's right

That's certainly the same way I've understood what Cuiv is saying in the videos around this set up Cimh. Your image earlier is certainly impressive - I've been reluctant to add the wedge in, but you've tempted me again! Thanks for the detailed write up too 👍

[Oortraged]

2 hours ago, Elp said:

I don't have a SS but this is what I do. I stack every session generally the next day with calibration files, then to complete a project stack each stack (you have to go through the usual workflow, but no calibration, just register and stack). It's generally better to stack all frames in one go rather than stack stacks, but the above is easier to mentally manage, it's also a good way to check you didn't have issues during the session.

Regarding satellite trails, if you're using standard AP software to stack, use a Kappa Sigma rejection algorithm with a narrow or low outlier range (you'll have to test what works) and it'll remove the trails in the stack as long as you have a largish number of total subs.

Thanks Elp, I've had the same question and appreciate the guidance!

[LDW1]

3 hours ago, cimh said:

Yes, because Seestar is tilted then viewing towards the south becomes restricted as it thinks the horizon is much higher than it really is. I think polaris sinks lower in the sky as you move towards the equator in which case people living in lower latitudes will be more restricted as the seestar has to be tilted more to line up with Polaris.  I hope that's right

And 90% of the great objects are in the south quadrant so if it takes the horizon too high a SS'er will miss out on a high number of dso's !  In the summer Scorpius, Sagittarius, etc. and a lot that goes alongside them !  Hopefully not but ......... ?

Edited April 17 by LDW1

[Elp]

I hate my south roof... there's one directly north too. And a lamppost directly east...

[LDW1]

4 minutes ago, Elp said:

I hate my south roof... there's one directly north too. And a lamppost directly east...

Better take up golf, lol !

[Elp]

3 minutes ago, LDW1 said:

Better take up golf, lol !

Can't afford it, it's all invested into astro.

[LaurenceT]

I decided to have a go at the Iris Nebula when the stars appeared briefly last night. I only managed to get 20 minutes of total integration of 10 second subs.

It was over the northern part of my garden which is heavily light polluted due to street lamps and Heathrow in the distance so I have previously avoided it. There were also many intermittent cloud bands.

I tried several apps for stacking and stretching but the best one for bringing out the blue nebulosity turned out to be Astro Pixel Processor, unfortunately there is no structural detail visible which doesn't really surprise me!

I realise this is precisely why I have the Seestar, the forecasts last night showed continual cloud cover, I wouldn't have contemplated setting up my astrophotography kit. If I had set up my longest scope the iris nebula would still have been a tiny blob.

Setting up the Seestar took just over 5 minutes.

[paulastro]

APRIL 16TH/17TH  

A few Seestar images.

https://stargazerslounge.com/topic/421231-april-16th17th-lunar-obs-deep-sky-with-seestar-s50/#comment-4478869

 

[LDW1]

The 2" filter holder that I ordered from Oak Astro just arrived !  It works well, fits a little snug so I will sand it a bit, works well when the SS retracts as designed.  I can hardly wait to try it with several of my 2" scope filters, even if they don't work it wll be fun experimenting.  The filter shown is a Burgess CX - 4, may he RIP, a great astro builder !

 

Edited April 18 by LDW1

[Neil H]

Hi I want to ask a question but don't know we're to ask it so I hope you don't mind me asking here , when I use my seestar most of the time I get messages like "stack failed star trails so binned" or not enough stars , any ideas why I get these ?

Kind regards Neil

[LaurenceT]

3 minutes ago, Neil H said:

Hi I want to ask a question but don't know we're to ask it so I hope you don't mind me asking here , when I use my seestar most of the time I get messages like "stack failed star trails so binned" or not enough stars , any ideas why I get these ?

Kind regards Neil

I think there can be various causes, but the one that comes to mind is that if the target is very close to the zenith then alt az mounts have more difficulty tracking.

[paulastro]

19 minutes ago, Neil H said:

Hi I want to ask a question but don't know we're to ask it so I hope you don't mind me asking here , when I use my seestar most of the time I get messages like "stack failed star trails so binned" or not enough stars , any ideas why I get these ?

Kind regards Neil

It can also be affected by wind which can cause the stars to trail.  Even if there's a little wind I try to set up where it's sheltered.  If it's too windy I leave it fir another day.

[Geoff Lister]

3 hours ago, LaurenceT said:

the one that comes to mind is that if the target is very close to the zenith then alt az mounts have more difficulty tracking.

I found that there is a mechanical stop at about 85 degrees in elevation (altitude), so there will be a "blind" cone within about 5 degrees of the zenith. The "voice" confirms the end stop when you hit it. If clouds permit, you can wait until the target drops in altitude.

Geoff

[AstroKeith]

Imaging near the Zenith produces massive image rotation. Even if the Seestar can compensate when stacking, the useable field of view reduces from a tall rectangle towards a square.

The image below has been black level adjusted to demonstrate - M51 was about 82 degrees altitude.

Edited April 19 by AstroKeith

[cimh]

21 hours ago, AstroKeith said:

Imaging near the Zenith produces massive image rotation. Even if the Seestar can compensate when stacking, the useable field of view reduces from a tall rectangle towards a square.

The image below has been black level adjusted to demonstrate - M51 was about 82 degrees altitude.

 

This is the advantage of the EQ mount. This is an uncropped stacked & processed image taken last night over 1.5hrs. (M51 was at 52 degrees at the start, 82 by the end).

 

 

Edited April 20 by cimh
adding update

[LDW1]

2 minutes ago, cimh said:

This is the advantage of the EQ mount. This is an uncropped stacked & processed image taken last night over 1.5hrs. (M51 was at 52 degrees at the start, 82 by the end).

 

 

I don't see much difference unless I stare for a while or maybe use a magnifying glass vs the hassles of using an EQ set up ! ZWO got it right and I think at a much better price, no wonder 98% of us have smiles on our faces, lol !

[cimh]

45 minutes ago, LDW1 said:

I don't see much difference unless I stare for a while or maybe use a magnifying glass vs the hassles of using an EQ set up ! ZWO got it right and I think at a much better price, no wonder 98% of us have smiles on our faces, lol !

I agree,  on a small DSO rotation does not matter, you can just crop. But it might make a difference on larger objects and longer time frames. I am not promoting EQ and I agree it isn't needed to enjoy the Seestar. But I think it is interesting. The extra set up time is 3-5 mins (sighting polaris, 1 random plate solve followed by the horizon calibration. I have only used it twice. Will I continue to use it ? . . Probably. It is simple to use but time will tell. But yes, the joy of the Seestar is its ease of use and set up speed, so I would not continue to use EQ if either of these were affected.

Edited April 20 by cimh
shorten

[cimh]

Following on from Astrokeiths post.

On 19/04/2024 at 15:45, AstroKeith said:

Imaging near the Zenith produces massive image rotation. Even if the Seestar can compensate when stacking, the useable field of view reduces from a tall rectangle towards a square

 

The images below show the 20s images of M51 taken at 21.13 & 23.00 at the start and end of my session (1hr 45 mins) I have drawn a line between M51 and a star. From this and the stars at the edges of both images that EQ mode does prevent any rotation over this time period.  

   

[M40]

On 19/04/2024 at 11:21, Neil H said:

Hi I want to ask a question but don't know we're to ask it so I hope you don't mind me asking here , when I use my seestar most of the time I get messages like "stack failed star trails so binned" or not enough stars , any ideas why I get these ?

Kind regards Neil

I think there's two things going on here, the star trails I've found comes from vibration or wind. We live reasonably close to a main road and should a lorry hit one of the many potholes it shakes the ss50 and you get the fail message. My thoughts there are to get some of those anti vibration pads to see if it helps. With the not enough stars, I think thats down to clouds. It happens a lot to me with the asiair and I up the gain on the camera which either helps or its game over for the night.

Is there a manual gain setting for the ss50?

[cimh]

On 19/04/2024 at 11:21, Neil H said:

when I use my seestar most of the time I get messages like "stack failed star trails so binned" or not enough stars , any ideas why I get these ?

That is frustrating when it happens - Other things to think about - Compass calibration, Is tripod level, is the seestar screwed to the tripod reasonably well so there is no slip, are the stars focussed. If all of that is ok and there is no wind perhaps try imaging something lower in the sky to see if that helps.

[LDW1]

A couple more from a not too bad sky !

Edited April 20 by LDW1
reduce photo size