First night guiding, some advice please :D

[Grant93]

Hello everyone,

Had a nice week off work with a nice gift of a ASI224mc for Christmas for use of mainly guiding but also future Lunar and Planetry work once I get some more focal length for it .

But as typical, havent had a single clear night whilst being off during a new moon and nice gifts to try out. But I had a partial clear night yesterday, so I decided to set up to try and educate myself on guiding and get some minor amounts of data to try it out, just so I wouldnt waste a fully clear night learning. I got the hang of it mostly, managing my first 2 minute exposures on the ZS61 with nice round stars, don't think I would want much longer as the histogram seems to be in the perfect spot at 2mins in my Bortle5, I'll explain how I had everything set up and have a few questions so please bare with me .

I had the Raspberry Pi4 plugged into the guidecam and 800d. I had the guidecam plugged into the Autoguiding port, and I had an ethernet from the laptop into the house. I don't plug the raspberry pi4 into the HEQ5 as I like to use my handcontroller as I only stick to one object per night and also I like the polar allignment feature on the controller, seems to do a great job. I had Ekos and PHD4 open on the pi.

1. Guidecam exposure - It didn't guide very well when the exposure was higher than .2s on the guidecam, it would cause the stars to zigzag on the final picture, I thought I was ok with .2s with that but then I read most people use between 1-4s guidecam exposure. How come this would happen with even a 1 second exposure on the guidecam.

2. Focus in the guidecam - How in focus does the guidecam have to be? Am I ok aslong as I see stars on the screen that are near enough (but not perfectly) pinpoint?

3. Dithering only being plugged into the autoguide port - As I don't have my Pi4 plugged into the mount, will PHD4 still work with Ekos and dither through the autoguide port between images, or to dither will I have to have Ekos controlling my mount too? (I hope not, as I said above I like using the hand controller).

4. A question I've always wondered but unrelated to guiding, but don't seem to be able to find a clear answer to - Does anyone ever shoot through wispy high clouds? I often watch some of the more popular youtubers, and have noticed they sometimes mention of high wispy clouds, but they're shooting anyway. But some people also say they throw away data if it has any amount of cloud drifting through it. What are your thoughts?

Hope everyone had a nice Christmas!

Thanks for your time and help .

Grant

 

[teoria_del_big_bang]

I had the Raspberry Pi4 plugged into the guide cam and 800d. I had the guide cam plugged into the Autoguiding port, and I had an ethernet from the laptop into the house. I don't plug the raspberry pi4 into the HEQ5 as I like to use my hand-controller as I only stick to one object per night and also I like the polar alignment feature on the controller, seems to do a great job. I had Ekos and PHD4 open on the pi.
I am not quite sure what you mean here, please forgive me but can you explain a but further?
You say RPi4 plugged into the guide cam - I presume this is via the USB cable into the USB on the CCD ?
But then you are also using the guide cam autoguiding port. I am also assuming by this you mean the ST-4 port on the CCD, is that correct and if so where does the other end go ? again my presumption is it goes directly to the mount.

 

1. Guidecam exposure - It didn't guide very well when the exposure was higher than .2s on the guidecam, it would cause the stars to zigzag on the final picture, I thought I was ok with .2s with that but then I read most people use between 1-4s guidecam exposure. How come this would happen with even a 1 second exposure on the guidecam.
If I read this correctly you are using 0.2 sec exposures on guidecam, this seems very fast as I think the norm is between 1 and 4 Seconds, in my case this somewhere about 1.5 to 2 seconds seems to work best.

2. Focus in the guidecam - How in focus does the guidecam have to be? Am I ok aslong as I see stars on the screen that are near enough (but not perfectly) pinpoint?
I think focus needs to be somewhere close but not necessary to have pin point focus.
Some say slightly out of focus actually works better but personally never really seen a difference in correct focus and slightly out of focus.

3. Dithering only being plugged into the autoguide port - As I don't have my Pi4 plugged into the mount, will PHD4 still work with Ekos and dither through the autoguide port between images, or to dither will I have to have Ekos controlling my mount too? (I hope not, as I said above I like using the hand controller).
I don't think so as PHD2 will control the dithering via the guidecam and ST-4 cable to the mount (I say I think as I have never used ST-4 so am assuming this to some extent) 

4. A question I've always wondered but unrelated to guiding, but don't seem to be able to find a clear answer to - Does anyone ever shoot through wispy high clouds? I often watch some of the more popular youtubers, and have noticed they sometimes mention of high wispy clouds, but they're shooting anyway. But some people also say they throw away data if it has any amount of cloud drifting through it. What are your thoughts?
I am sure in the UK many have to do some amount of imaging through some high thin cloud.
It is all a matter of how thick the high cloud is and how much of it is about.
If in the UK we wait for absolutely not a single cloud then those nights would be very few and far between.
For me at least it seems to be a matter of judging how much cloud is about and whether it is worth an all night imaging session.
Then if all goes well I would look at stretched images of each frame I took and decide whether to keep or discard from a final image.
Trouble I find with clouds is that if I decide to leave the rig out all night imaging, unattended, often the clods can momentarily cover my target enough at some stage  to stop guiding as it looses the guide star for a while and thus stops the sequence and the rest of the night my target may be clear but the imaging sequence has stopped.
 

For me what seems odd in your setup is why you have to have 0.2 Sec exposure time and not the more usual 1 to 4 Sec.
What is the tracking like without any guiding at all, if the PA is good then you should get 30S exposures at least without significant star trails.
Remember that PHD2 and a guide-cam are there just to get that bit better guiding than your tracking on the mount, to allow for 5 to 10 minute exposures or higher, it should not be the only thing that is keeping your camera on target. 
So maybe the first approach is to get decent tracking of the mount unguided, then add the guiding.
Are you sure the tracking rate is 1X sidereal and set to Northern hemisphere ?
I am not familiar with your actual mount but don't see why it should be any different to the HEQ5 or IOptron CEM60 I use. 

Maybe if you can show your PHD2 settings and maybe one of your images with zig-zag stars when using 1S exposures on guide cam it may help/

Steve

Edited January 2, 2022 by teoria_del_big_bang

[Grant93]

16 minutes ago, teoria_del_big_bang said:

I had the Raspberry Pi4 plugged into the guide cam and 800d. I had the guide cam plugged into the Autoguiding port, and I had an ethernet from the laptop into the house. I don't plug the raspberry pi4 into the HEQ5 as I like to use my hand-controller as I only stick to one object per night and also I like the polar alignment feature on the controller, seems to do a great job. I had Ekos and PHD4 open on the pi.
I am not quite sure what you mean here, please forgive me but can you explain a but further?
You say RPi4 plugged into the guide cam - I presume this is via the USB cable into the USB on the CCD ?
But then you are also using the guide cam autoguiding port. I am also assuming by this you mean the ST-4 port on the CCD, is that correct and if so where does the other end go ? again my presumption is it goes directly to the mount.

Yes, USB from the Pi to the Guidecam, then from the guidecam Via ST-4 port to the autoguiding port on the mount. Just specified this really as I wanted to reiterate this is the only thing other than the hand controller plugged into the mount.

18 minutes ago, teoria_del_big_bang said:

1. Guidecam exposure - It didn't guide very well when the exposure was higher than .2s on the guidecam, it would cause the stars to zigzag on the final picture, I thought I was ok with .2s with that but then I read most people use between 1-4s guidecam exposure. How come this would happen with even a 1 second exposure on the guidecam.
If I read this correctly you are using 0.2 sec exposures on guidecam, this seems very fast as I think the norm is between 1 and 4 Seconds, in my case this somewhere about 1.5 to 2 seconds seems to work best.

 

Yes this is what I thought that its extremely short.. I didnt try longer exposures for some reason, but tried the shorter ones and that seemed to help, will try longer next time and see how it goes.

19 minutes ago, teoria_del_big_bang said:

4. A question I've always wondered but unrelated to guiding, but don't seem to be able to find a clear answer to - Does anyone ever shoot through wispy high clouds? I often watch some of the more popular youtubers, and have noticed they sometimes mention of high wispy clouds, but they're shooting anyway. But some people also say they throw away data if it has any amount of cloud drifting through it. What are your thoughts?
I am sure in the UK many have to do some amount of imaging through some high thin cloud.
It is all a matter of how thick the high cloud is and how much of it is about.
If in the UK we wait for absolutely not a single cloud then those nights would be very few and far between.
For me at least it seems to be a matter of judging how much cloud is about and whether it is worth an all night imaging session.
Then if all goes well I would look at stretched images of each frame I took and decide whether to keep or discard from a final image.
Trouble I find with clouds is that if I decide to leave the rig out all night imaging, unattended, often the clods can momentarily cover my target enough at some stage  to stop guiding as it looses the guide star for a while and thus stops the sequence and the rest of the night my target may be clear but the imaging sequence has stopped.

This is the answer I wanted - as I always give up nights with high wispy clouds, because I thought it would be a waste of time.. Which means I get 4 nights a month imaging as I have to work it around my worklife.. more if I am super lucky.

 

21 minutes ago, teoria_del_big_bang said:

For me what seems odd in your setup is why you have to have 0.2 Sec exposure time and not the more usual 1 to 4 Sec.

What is the tracking like without any guiding at all, if the PA is good then you should get 30S exposures at least without significant star trails.
Remember that PHD2 and a guide-cam are there just to get that bit better guiding than your tracking on the mount, to allow for 5 to 10 minute exposures or higher, it should not be the only thing that is keeping your camera on target. 
So maybe the first approach is to get decent tracking of the mount unguided, then add the guiding.
Are you sure the tracking rate is 1X sidereal and set to Northern hemisphere ?
I am not familiar with your actual mount but don't see why it should be any different to the HEQ5 or IOptron CEM60 I use. 

Maybe if you can show your PHD2 settings and maybe one of your images with zig-zag stars when using 1S exposures on guide cam it may help/

Steve

My tracking is fine when I polar allign via scope, then do a couple of polar allignments with help via handcontroller.. With the ZS61 and 800D/600D I can get 40-50s unguided before noticeable trails. Which I did all this before guiding, the actual trails before I lowered the exposure on the guidecam were more extreme than anything I'd seen. I'm not sure what settings I should show on PHD2, but heres and image of the zigzag trails when at 1s Guidecam exposure.

Thank you for the detailed answer & Help

Grant

 

[kens]

Those start trails look remakably like what you would get if PHD2 was calibrating while you were imaging. With ST4 guiding you calibrate on each target so you need to let the claibration complete before starting imaging.

Another possible reason for poor guiding with the longer guide expsoures is that ht e guide star is saturated. Use the star profile view to check that and if the profile has a flat top, reduce the gain on your camera.

If you can attach your guide log that would be helpful to analyse.

[teoria_del_big_bang]

I think @kens has hit the nail on the head.
But why it does not show the same effect at faster frame rates I am not sure, maybe it just calibrates much faster and so you do not see the effect so much in the final image as there is more exposure when guiding correctly.

Steve

 

Edited January 2, 2022 by teoria_del_big_bang

[teoria_del_big_bang]

1 minute ago, kens said:

Those start trails look remakably like what you would get if PHD2 was calibrating while you were imaging. With ST4 guiding you calibrate on each target so you need to let the claibration complete before starting imaging.

Another possible reason for poor guiding with the longer guide expsoures is that ht e guide star is saturated. Use the star profile view to check that and if the profile has a flat top, reduce the gain on your camera.

If you can attach your guide log that would be helpful to analyse.

Ah, yes I think you are right, I couldn't think where I had seem similar images before but now that has remined me 🙂 

Steve

[kens]

6 minutes ago, teoria_del_big_bang said:

I think @kens has hit the nail on the head.
But why it does not show the same effect at faster frame rates I am not sure, maybe it just calibrates much faster and so you do not see the effect so much in the final image as there is more exposure when guiding correctly.

Steve

 

I suspect you are right and it is just that the calibration goes much faster. The good news is that it looks like a good, orthogonal calibration

[Grant93]

Well that may explain it then.. I was clicking start guiding and the photographing sequence at the same time 😂 I never realised there was a calibration between 🤭

[teoria_del_big_bang]

1 minute ago, Grant93 said:

Well that may explain it then.. I was clicking start guiding and the photographing sequence at the same time 😂 I never realised there was a calibration between 🤭

If you watch the PHD2 screen it will tell you at the bottom LH of the screen when it is calibrating, it will say something like "West step" then a number and a distance., also to begin with at the bottom RH it will have CAL in red until calibration is finished then it turns green.

Steve

[michael8554]

Hi Grant

I suggest you read how to use PHD2:

https://openphdguiding.org/PHD2_User_Guide.pdf

And these :

https://openphdguiding.org/phd2-best-practices/

Michael

[alacant]

20 hours ago, Grant93 said:

I had Ekos and PHD4 open on the pi.

Hi

Keep it simple? You may find it -considerably- easier to use EKOS' own first-rate guider rather than adding a third party app to the mix. 

Cheers

[Grant93]

Just now, alacant said:

Hi

Keep it simple? You may find it -considerably- easier to use EKOS' own first-rate guider rather than adding a third party app to the mix. 

Cheers

I didnt realise EKOS has an inbuilt guider Ill have to check that out next time..

Thank you

[teoria_del_big_bang]

7 minutes ago, alacant said:

Hi

Keep it simple? You may find it -considerably- easier to use EKOS' own first-rate guider rather than adding a third party app to the mix. 

Cheers

I agree to keep it simple and use EKOS, but can you use ST-4 guiding with EKOS ?
I did not suggest this because the OP did not want to connect the mount to the RPi, although I think that would be the best route to take.

Steve

[alacant]

27 minutes ago, teoria_del_big_bang said:

ST-4 guiding with EKOS ?

Yes, of course. On the guide tab, simply select:

Via -> On Camera

The connections are

USB: computer - camera

ST4: camera - mount

Note: have at least one spare st4 cable and/or get a proper flexible one.

HTH

Edited January 3, 2022 by alacant

[alacant]

34 minutes ago, Grant93 said:

didnt realise EKOS has an inbuilt guider

Your experience guiding just got a lot easier!

[Grant93]

1 hour ago, teoria_del_big_bang said:

I agree to keep it simple and use EKOS, but can you use ST-4 guiding with EKOS ?
I did not suggest this because the OP did not want to connect the mount to the RPi, although I think that would be the best route to take.

Steve

The reason I don't want to plug my Pi into the mount, is because when I set up I like to do the manual polar allign with the polarscope, then polar allign with the function on the hand controller, which I can do using the screen on my DSLR, then I can slew to the object I plan on imaging, check framing all without the use of a laptop, and I can keep that inside. And as I only ever want to stick to one object on a given night, I don't feel I need to control the mount from my laptop. I can then go inside, and I am hooked upto the Pi on my laptop via a long long ethernet 😅 (I find the Wifi slow and unrealiable on the Pi). And just control the imaging and guiding from my laptop.

This is just me explaining the route I take, not that I think this is the best way to do it, so if anyone has better ideas, please do say as I am always open to advice.

 

[teoria_del_big_bang]

12 minutes ago, Grant93 said:

The reason I don't want to plug my Pi into the mount, is because when I set up I like to do the manual polar allign with the polarscope, then polar allign with the function on the hand controller, which I can do using the screen on my DSLR, then I can slew to the object I plan on imaging, check framing all without the use of a laptop, and I can keep that inside. And as I only ever want to stick to one object on a given night, I don't feel I need to control the mount from my laptop. I can then go inside, and I am hooked upto the Pi on my laptop via a long long ethernet 😅 (I find the Wifi slow and unrealiable on the Pi). And just control the imaging and guiding from my laptop.

This is just me explaining the route I take, not that I think this is the best way to do it, so if anyone has better ideas, please do say as I am always open to advice.

 

I think if that's the way you want to do it then I would go that route, at least for now.
I was just not aware the internal guider could use the ST-4 cable.
Once you have it working you can then think about whether you want to try EKOS pulse guiding, I think doing it this way does bring some advantages but get it working as it is and then think if you want, or would have any advantage, changing to using EKOS.

I have no real experience of using the ST-4 method and so cannot comment to whether this creates any difficulties for you or whether EKOS had any advantages, I know it is regarded as a bit of an outdated method by some but it is still used by many, maybe others can chip in with advice, but certainly get it working correctly as you are set up now and see what guiding does for your setup.

Good luck when you next get a clear night to try it 🙂 

Steve