SGP & PHD2 guidance

[souls33k3r]

Hi All,

So here we are with my second thread. Some of the things i would like to refine my process on so would appreciate some guidance.

This thread will also include a question related to PHD2 but only from the SGP standpoint so please do bear with me

Question 1) How do you set up your SGP for a sequence

Right so right now i'm creating sequence and imaging without any issue and one that works for me but i'm sure this isn't the correct way but just wanted your take on it and see if i can better this process. 

I have my scope in rough spot where my Lum filter is in focus'ish. I fire up SGP, connect all my gear, create the sequence by choosing "Framing and mosaic wizard", fetch the object, draw the rectangle and create the sequence. I then run the sequence which platesolves the object. Just as the sequence is about to begin, i pause the sequence, choose my filter to say "Ha" and use "Frame and Focus", put bahtinov mask on and focus my Ha. Once the Ha is focused I then resume the sequence and away i go. 

What i would like to know, what am i doing wrong here because the way how i see it i would like to focus my first filter before the sequence begins and then it should platesolve and my sequence should carry on.

Question 2) PHD2 losing guide star (Star loss) and SGP ending sequence

Again might be a very simple answer to this but i have had this issue where PHD2 would lose a guide star (my other PHD2 thread explain all the issues that i've been having with the software so if you think this question is best answered there then please would appreciate that)

Now when the guide star is lost, SGP wants to end the sequence. How do you guys (those who do un-attended session and go to sleep) deal with this? Is there an option in SGP that you have to tick that if the guide star is lost to tell SGP to choose a new guide star and NOT give that message to end sequence? Also as per the other PHD2 thread, is there a way from SGP or PHD2 you can tell any of these softwares to choose a different exposure rate because some times i have to fiddle around with different exposures as my screen would show no stars and then dropping down the exposure rate to half a second would bring all the stars back and guiding is fine again.

Many thanks in advance.

[coatesg]

There's the sequence recovery options in the Tools > Options: "Sequence Options" dialog - this tells SGP to try and recover the sequence in certain circumstances (I could see this being eg after guide star loss due to cloud).

PHD2 has an auto exposure option in the exposure drop down but it's more for AO users from the docs - but I'm not sure that's really what you should be doing here: half second is a very short guide exposure and you're liable to chase seeing - multi second exposures will smooth out the seeing and potentially give you (or the auto-selection) algorithm more choice in finding a guide star.

[souls33k3r]

2 minutes ago, coatesg said:

There's the sequence recovery options in the Tools > Options: "Sequence Options" dialog - this tells SGP to try and recover the sequence in certain circumstances (I could see this being eg after guide star loss due to cloud).

PHD2 has an auto exposure option in the exposure drop down but it's more for AO users from the docs - but I'm not sure that's really what you should be doing here: half second is a very short guide exposure and you're liable to chase seeing - multi second exposures will smooth out the seeing and potentially give you (or the auto-selection) algorithm more choice in finding a guide star.

Cheers @coatesg, i'll taker a look at the "Sequence Option" dialog, but am i doing it the correct way this whole create sequence, platesolve and then pause sequence and then focus filter and resume sequence? I'm sure there must be a better way of doing all of this.

As for the PHD2, the issue has been weird where say at 2s i'm guiding fine and then all of a sudden i see "Star loss" message and can only see one of two of the brightest stars and then as soon as i drop the exposure to half a second, i see all the stars back again and guiding is fine. I must admit, at this is what i've seen only when guiding at 2s and then dropping it to 1.5s is fine. I'm using QHY5L-II M camera for my guiding.

[RayD]

Hi mate.  You're not far away.

I personally only use the framing and mosaic module if I am doing a mosaic, but getting and plate solving on your image is the right first step, but you can just have your sequence centre on your target on start (click the gear icon next to your target and tick the centre on box).  SO long as you have the coordinates, which you can get and apply to your target during a plate solve, then the rest happens when the sequence starts.

Once the sequence starts you can select for it to focus at that point, or on filter change.  I tend to not focus on sequence start, but do the first focus before starting so I can get PHD2 set up (I use OAG), and then focus again on every filter change, and at every 1.0 degree of temperature change.

All te processes once you select start sequence should be fully automated.  I'm hopefully imaging tonight, so if you want me to record a video of my procedure I'm happy to.

[souls33k3r]

3 minutes ago, RayD said:

Hi mate.  You're not far away.

I personally only use the framing and mosaic module if I am doing a mosaic, but getting and plate solving on your image is the right first step, but you can just have your sequence centre on your target on start (click the gear icon next to your target and tick the centre on box).  SO long as you have the coordinates, which you can get and apply to your target during a plate solve, then the rest happens when the sequence starts.

Once the sequence starts you can select for it to focus at that point, or on filter change.  I tend to not focus on sequence start, but do the first focus before starting so I can get PHD2 set up (I use OAG), and then focus again on every filter change, and at every 1.0 degree of temperature change.

All te processes once you select start sequence should be fully automated.  I'm hopefully imaging tonight, so if you want me to record a video of my procedure I'm happy to.

You top top man. That would be handy for sure only if it's not going to make to lose your focus on the imaging run mate.

One slight issue, i am manually focusing using bahtinov mask.

and this PHD2 guide star loss thing is super annoying. How does SGP handle (or tells PHD2 to handle that) then? unless there's a setting in PHD2 that you can set to say choose the next available guide star before SGP throws a fit?

[RayD]

2 minutes ago, souls33k3r said:

You top top man. That would be handy for sure only if it's not going to make to lose your focus on the imaging run mate.

One slight issue, i am manually focusing using bahtinov mask.

and this PHD2 guide star loss thing is super annoying. How does SGP handle (or tells PHD2 to handle that) then? unless there's a setting in PHD2 that you can set to say choose the next available guide star before SGP throws a fit?

Ah sorry mate, I thought you had auto-focus for some reason.  You do it manually......that is so last year 

In that case, focus first on your main scope and your guide then plates olve your image and then start your run.  You will need to focus again if you are using a different filter for capture if yours are not par focal, but I would anyway as they are not normally spot on.

I'll log on and have a look at the PHD2 issue.  Don't forget most of the guiding settings are controlled by PHD2, not SGP.  The selection and re-selection of guide stars is carried out by PHD2.  I'm not sure why you would be getting better results with shorter subs as that is a little odd.  Have you checked over your PHHD2 settings with regards to camera pixel size and FL etc?

[RayD]

Don't forget of course that the centre on sequence start option mentioned above will do the plate solve for you.  It will slew to the target coordinates and then plate solve, all automatically.

[coatesg]

I think for the PHD2 guide star issue, SGP doesn't care less what it's doing - it just tells it to start/stop guiding and acts on the numerical output.

If you can get PHD2 to auto-select and guide on it's own, then SGP will work. If you are using short exposures, I think making them longer will help with not chasing seeing and having more stars to auto-select.

Also, what happens when it loses the guide star? Stars don't tend to just disappear, unless you're guiding behind the filter and you've just done a filter change? What kind of SNR are you getting for the guide star in PHD2? 

[RayD]

1 minute ago, coatesg said:

I think for the PHD2 guide star issue, SGP doesn't care less what it's doing - it just tells it to start/stop guiding and acts on the numerical output.

If you can get PHD2 to auto-select and guide on it's own, then SGP will work. If you are using short exposures, I think making them longer will help with not chasing seeing and having more stars to auto-select.

Also, what happens when it loses the guide star? Stars don't tend to just disappear, unless you're guiding behind the filter and you've just done a filter change? What kind of SNR are you getting for the guide star in PHD2? 

Spot on Graeme.  PHD2 does the work, SGP just interfaces with it but doesn't do any of the guiding.  

That's what I can't work out with the stars, is that shorter exposures are better, but that doesn't make sense to me as the SNR would normally then drop and the fainter stars would disappear.

[souls33k3r]

10 minutes ago, RayD said:

Ah sorry mate, I thought you had auto-focus for some reason.  You do it manually......that is so last year 

In that case, focus first on your main scope and your guide then plates olve your image and then start your run.  You will need to focus again if you are using a different filter for capture if yours are not par focal, but I would anyway as they are not normally spot on.

I'll log on and have a look at the PHD2 issue.  Don't forget most of the guiding settings are controlled by PHD2, not SGP.  The selection and re-selection of guide stars is carried out by PHD2.  I'm not sure why you would be getting better results with shorter subs as that is a little odd.  Have you checked over your PHHD2 settings with regards to camera pixel size and FL etc?

Hahahaha trust me, i would've bought a focuser if i had the necessary funds. Was going to last October and then went to Kelling Heath and came back with a mission to sort out my cable management and splashed out on the Pegasus and the Power Supply. Now in the midst of saving up once again .. but very soon i hope

I'm using Astronomik NB filters and Ha & SII are very parfocal (super tiny adjustment required) but the OIII is a little out, again by not that much but i do focus on filter change.

With regards to focus (and here's a real noobish question) does it matter that i have to focus on the object that i'm imaging? What i'm trying to say here is that while my scope is pointing to the celestial pole, can i not just focus using my initial filter and then platesolve it to my target and my object will be in focus too? This will save me the headache of doing platesolving and then pause the sequence and resume.

Yeah all settings are correct, it's just this weird behavior where the guide star gets lost and then PHD is unable to find a new guide star and SGP wants to end the sequence because PHD2 was unable to find the guide star and yeah this dropping down of the exposure setting didn't make sense to me. I sort of know what to do to fix when this happens but then that means i have to be glued to my PHD2 guiding which defeats the purpose.

[souls33k3r]

I'm not sure if the guide logs will have this information as to why this happens? I don't know how to read the logs but can certainly post them here if it helps?

[souls33k3r]

17 minutes ago, RayD said:

Don't forget of course that the centre on sequence start option mentioned above will do the plate solve for you.  It will slew to the target coordinates and then plate solve, all automatically.

Cheers mate, i'll most certainly look in to this as well. I love SGP for what it is, just getting the hang of this software.

[RayD]

5 minutes ago, souls33k3r said:

Hahahaha trust me, i would've bought a focuser if i had the necessary funds. Was going to last October and then went to Kelling Heath and came back with a mission to sort out my cable management and splashed out on the Pegasus and the Power Supply. Now in the midst of saving up once again .. but very soon i hope

I'm using Astronomik NB filters and Ha & SII are very parfocal (super tiny adjustment required) but the OIII is a little out, again by not that much but i do focus on filter change.

With regards to focus (and here's a real noobish question) does it matter that i have to focus on the object that i'm imaging? What i'm trying to say here is that while my scope is pointing to the celestial pole, can i not just focus using my initial filter and then platesolve it to my target and my object will be in focus too? This will save me the headache of doing platesolving and then pause the sequence and resume.

Yeah all settings are correct, it's just this weird behavior where the guide star gets lost and then PHD is unable to find a new guide star and SGP wants to end the sequence because PHD2 was unable to find the guide star and yeah this dropping down of the exposure setting didn't make sense to me. I sort of know what to do to fix when this happens but then that means i have to be glued to my PHD2 guiding which defeats the purpose.

In an ideal world you would focus where you are imaging but I would think it will work fine doing it at the CP and then moving to your target.

Once you've focused you can then hit start sequence, it should look up your target coordinates, slew, solve and centre and then image.  You then set the sequence to pause after the event to allow you to focus on your new filter.

[souls33k3r]

3 minutes ago, RayD said:

In an ideal world you would focus where you are imaging but I would think it will work fine doing it at the CP and then moving to your target.

Once you've focused you can then hit start sequence, it should look up your target coordinates, slew, solve and centre and then image.  You then set the sequence to pause after the event to allow you to focus on your new filter.

That's exactly what i was thinking.

[RayD]

12 minutes ago, souls33k3r said:

Cheers mate, i'll most certainly look in to this as well. I love SGP for what it is, just getting the hang of this software.

It's a great piece of software, and the more you use it the more you like it.  Lots of little things which make imaging a doddle.

Well worth persevering with it. 

[souls33k3r]

Here's the PHD2 guide log if this makes any sense to you guys.

PHD2_GuideLog_2018-05-02_214322.txt

[RayD]

2 minutes ago, souls33k3r said:

Here's the PHD2 guide log if this makes any sense to you guys.

PHD2_GuideLog_2018-05-02_214322.txt

If you want to view logs yourself mate you can download the free log viewer here.

I'll have a look and see if anything stands out.

[souls33k3r]

Just now, RayD said:

If you want to view logs yourself mate you can download the free log viewer here.

I'll have a look and see if anything stands out.

Yeah that's the software i do have as well. I've got it opened up on my work PC but i don't quite understand what i'm looking here if i'm being honest Was about to google for some help around this.

Take a look at your leisure mate, no immediate rush. Please ignore the bad total RMS I generally tend to ignore that number as long as my stars come out round  But the thing which this guide log (am hoping) will point out the reason for the star loss and when i have to switch from 2s to 1.5, i can see the stars better on the screen.

[RayD]

3 minutes ago, souls33k3r said:

Yeah that's the software i do have as well. I've got it opened up on my work PC but i don't quite understand what i'm looking here if i'm being honest Was about to google for some help around this.

Take a look at your leisure mate, no immediate rush. Please ignore the bad total RMS I generally tend to ignore that number as long as my stars come out round  But the thing which this guide log (am hoping) will point out the reason for the star loss and when i have to switch from 2s to 1.5, i can see the stars better on the screen.

No worries.  It just says star lost low mass and low SNR, which is normally cloud or bad seeing, and helped with increased exposure length, not less.  You have a short FL (130mm) so you may want to have a try at longer lengths.  Don't be afraid to try 4 or 5 seconds.

[souls33k3r]

7 minutes ago, RayD said:

No worries.  It just says star lost low mass and low SNR, which is normally cloud or bad seeing, and helped with increased exposure length, not less.  You have a short FL (130mm) so you may want to have a try at longer lengths.  Don't be afraid to try 4 or 5 seconds.

Cheers for looking in to this mate. That's really so kind of you.

It sure is a tiny little thing that i've got which to be honest is yet to fail me. 

I was tempted on using a longer focal length guidescope but like i said, this tiny thing just works. I will change it to something like a 60mm if needs be.

Will make sure i try 4/5 seconds too.

The seeing was alright the other night, it wasn't bad bad i must admit. 

Is there a setting in PHD2 that you can select that if there is a star loss it should switch to a different guide star within x number of seconds? and also PHD2 to switch the guide exposures up and down as it sees fit as the night progresses? Not sure if i'm asking too much of PHD2

[RayD]

1 minute ago, souls33k3r said:

It sure is a tiny little thing that i've got which to be honest is yet to fail me. 

I was tempted on using a longer focal length guidescope but like i said, this tiny thing just works. I will change it to something like a 60mm if needs be.

Will make sure i try 4/5 seconds too.

The seeing was alright the other night, it wasn't bad bad i must admit. 

Is there a setting in PHD2 that you can select that if there is a star loss it should switch to a different guide star within x number of seconds? and also PHD2 to switch the guide exposures up and down as it sees fit as the night progresses? Not sure if i'm asking too much of PHD2

No I'm not saying it's too small mate, the mini guiders are fine, I'm just saying at this FL I'm guessing it is a small OTA so may need longer exposures.  If the SNR is low and the mass is changing etc. it would point to this.

I don't think you can get it to change guide star.  You can have it auto-select one, which is what I normally do, but unless you have cloud or change target you shouldn't need another star in theory.  Also once exposures are set they tend to stay the same, but you can set this to auto and it will try between the ranges set within the settings (brain).  I haven't had good results with this.

[RayD]

PS, If you are still using your Star71, I have a spare Lakeside that you can loan to see how you get on with it, complete with the bracket for that scope.

[souls33k3r]

2 minutes ago, RayD said:

No I'm not saying it's too small mate, the mini guiders are fine, I'm just saying at this FL I'm guessing it is a small OTA so may need longer exposures.  If the SNR is low and the mass is changing etc. it would point to this.

I don't think you can get it to change guide star.  You can have it auto-select one, which is what I normally do, but unless you have cloud or change target you shouldn't need another star in theory.  Also once exposures are set they tend to stay the same, but you can set this to auto and it will try between the ranges set within the settings (brain).  I haven't had good results with this.

ah, sorry i misunderstood what you meant Makes complete sense now mate. With regards to SNR of the star, i know someone is going to rip whatever hair is left on my head for saying this but i was told by Bern that it's ok to guide on a saturated star with this tiny thing. I have done so in the past and it has also worked.

Auto-select star, isn't it the ALT+S option? if so then that's what i do but that's when it begins the guiding isn't it. I was hoping that it auto selects a star during the guiding when it loses a star for whatever reason.

I'm pretty sure i did have the range selected for the exposure settings but not sure if there was a check box which i'm missing for it to auto adjust that. 

I sincerely do apologise for these noobish questions, it's just that i really want to get comfortable with PHD2. So far, i know how to make it work but would love for it to just do it's thing without me having to sit next to it and monitor eventually losing subs because PHD2 lost the star and SGP wants to end the sequence.

Speaking of which, is there was way to tell SGP for it NOT try to end the sequence but to wait until PHD2 find the star again?

[souls33k3r]

1 minute ago, RayD said:

PS, If you are still using your Star71, I have a spare Lakeside that you can loan to see how you get on with it, complete with the bracket for that scope.

Top gov mate. Much appreciated  Whenever you're next in town or around my place, just give me a shout and i'm more than happy to pop around myself matey. You're a super star

[RayD]

2 minutes ago, souls33k3r said:

Top gov mate. Much appreciated  Whenever you're next in town or around my place, just give me a shout and i'm more than happy to pop around myself matey. You're a super star

No worries mate.  I'm back home tomorrow and if the weather's nice I'll jump on the bike and pop over.  I have a controller also as I suspect you won't gave a lead for your Pegasus.  Is yours one with a RJ12 or the later RJ45 focus port?