Any pointers to improve guiding?

[Dan13]

Morning, first time out guiding last night and on the whole it was good and seemed to get some good sub time without trailing! 

I've attached some pictures below of my graphs , where I'm new I'm not sure if anything can be tweaked to achieve a more "tighter" guiding graph? 

 

Also attached a pic of sharp cap polar allign,while fiddly I did find it a very good tool 

[vlaiv]

What mount is this?

Only recommendation that I can give you - use a bit longer exposure. Maybe 3s or 4s. That will smooth out the seeing. Otherwise, that guiding is ok for mount like HEQ5/EQ6 or similar.

 

[Craney]

Your guiding graph does not look that bad to my untrained eye.   I suppose it depends what rig you are running..... 12" Newt on an Eq3 ??... now that would be impressive!!

On 'normal' everyday mounts people say balance is the key, and then follow that up with saying that the axes should be slightly biased ( East heavy etc ) towards a certain direction so that the motor gears/worms are always meshing and driving.

Thats a very satisfying polar alignment    

There is a "Guiding Assistant" on PhD2. 

Does a lot of fancy things I don't understand but does suggest improvements at the click of a button..... might be worth a try.

[Dan13]

5 minutes ago, vlaiv said:

What mount is this?

Only recommendation that I can give you - use a bit longer exposure. Maybe 3s or 4s. That will smooth out the seeing. Otherwise, that guiding is ok for mount like HEQ5/EQ6 or similar.

 

It's a HEQ5 Vlaiv, 

Ah ok I thought lower the better? I will give this a try next clear sky thank you.

[Dan13]

5 minutes ago, Craney said:

Your guiding graph does not look that bad to my untrained eye.   I suppose it depends what rig you are running..... 12" Newt on an Eq3 ??... now that would be impressive!!

On 'normal' everyday mounts people say balance is the key, and then follow that up with saying that the axes should be slightly biased ( East heavy etc ) towards a certain direction so that the motor gears/worms are always meshing and driving.

Thats a very satisfying polar alignment    

There is a "Guiding Assistant" on PhD2. 

Does a lot of fancy things I don't understand but does suggest improvements at the click of a button..... might be worth a try.

Hi , it's a HEQ5 with a 130pds and canon 600d.

I aim to be "east heavy" when balancing.

Excellent I will take a look at the assistant and see what it suggests, that's a great help.

And yes I was very happy with the PA last night !:)

[vlaiv]

1 minute ago, Dan13 said:

It's a HEQ5 Vlaiv, 

Ah ok I thought lower the better? I will give this a try next clear sky thank you.

On average night you can expect 0.6-0.7" RMS - as far as I can tell - you are already there?

On a good night - it will go down to 0.5" RMS total - but for that you need to smooth out the seeing - and this is why you want 3s exposure - it will average out seeing but still short enough to pick up any irregularity in mount motion.

[Tomatobro]

we are all graph watchers between takes but in the end its the quality of the subs that count.

[Dan13]

1 minute ago, vlaiv said:

On average night you can expect 0.6-0.7" RMS - as far as I can tell - you are already there?

On a good night - it will go down to 0.5" RMS total - but for that you need to smooth out the seeing - and this is why you want 3s exposure - it will average out seeing but still short enough to pick up any irregularity in mount motion.

Thank you, I'm guessing I change the slider to the right of the stop sign to do this yes? 

Also where does it say on that graph arc seconds/min?

[Dan13]

1 minute ago, Tomatobro said:

we are all graph watchers between takes but in the end its the quality of the subs that count.

This is very true! Other then a washed out evening due to the moon I did get some solid stars with no trailing at 4min subs so happy with that and seems I'm on the right track which is good to know

[vlaiv]

2 minutes ago, Dan13 said:

Thank you, I'm guessing I change the slider to the right of the stop sign to do this yes? 

Also where does it say on that graph arc seconds/min?

Red arrow shows drop down that you can use to select exposure length (slider is for brightness of the view, I believe - it won't change exposure length, but I'm not sure).

Blue arrow shows stats - RA error in pixels (and in arc seconds in parenthesis), DEC error and combined (total) error.

You want total error in arc seconds to be as low as possible - but 0.5" is realistic bottom value - it is very unlikely you'll have better value than that on Heq5 (Mesu200 does 0.2" for example - but costs x6-7 more ).

This value depends if you entered pixel size and focal length of your guide scope correctly - it's worth double checking those as well.

[Dan13]

1 minute ago, vlaiv said:

Red arrow shows drop down that you can use to select exposure length (slider is for brightness of the view, I believe - it won't change exposure length, but I'm not sure).

Blue arrow shows stats - RA error in pixels (and in arc seconds in parenthesis), DEC error and combined (total) error.

You want total error in arc seconds to be as low as possible - but 0.5" is realistic bottom value - it is very unlikely you'll have better value than that on Heq5 (Mesu200 does 0.2" for example - but costs x6-7 more ).

This value depends if you entered pixel size and focal length of your guide scope correctly - it's worth double checking those as well.

Excellent info Vlaiv greatly appriciated!! 

I see...so 0.67" I'm guessing under 1 arc second.

Yep checked pixel size last night and that's correct , looks like bar some very minor tweaks I'm achieving what I can do from the mount I have. That's great news and again thank you for the info and help 

[Star101]

My workflow on guiding is-

Connect PHD2, select the Brain or in menu "Advanced Setup" and Guiding, slect Clear Mount Calibtation.

Select a star and start guiding. Select 3 seconds on the bottom menu.   The PHD2 will calibrate West, East, North and South and then it will start guiding.

Once it starts guiding, go to the dropdown menus and select Tools, Guiding Assistant.

Let it run for at least 120 seconds. Basically wait until the numbers in the highlighted box become stable or as low as possible.

Once happy its run long enough and stable, select STOP. Two buttons will appear in the blank space below RMS readins. Apply both buttons and close.

Start imaging.

If you feel the graph could be better, try increasing the exposure time from 3 seconds upto what ever. With my Mesu mount, I run at 6s and have a very smooth graph.

[vlaiv]

18 minutes ago, Star101 said:

If you feel the graph could be better, try increasing the exposure time from 3 seconds upto what ever. With my Mesu mount, I run at 6s and have a very smooth graph.

Mount PE needs to be smooth to be able to guide with long exposures like 6 or 8s. I tried that with my Heq5 after belt mod and I've found that at around these exposure lengths PE starts to make my guiding worse - too much time passes between corrections and mount deviates too much. For rough mounts like Heq5 it's best to keep it under 4-5s.

[Skipper Billy]

You might find this document interesting - essentially its how to get the best out pf PHD2.

Second item down on this page. https://www.davidbanksastro.com/how-to

[RolandKol]

In my case with NEQ6 + 130PDS, guiding via EvoGuide +Asi120MM Mini

If I increase subs to 2-3s, I get results above 1.2 Total RMS...

1s produces around 0.7 - 0.8 Total RMS, which is enough for me, plus, calibration and PHD graph settling gets faster on 1s

Not everything works nice and as prescribed....

 

Edited May 7, 2020 by RolandKol

[Dan13]

48 minutes ago, Star101 said:

My workflow on guiding is-

Connect PHD2, select the Brain or in menu "Advanced Setup" and Guiding, slect Clear Mount Calibtation.

Select a star and start guiding. Select 3 seconds on the bottom menu.   The PHD2 will calibrate West, East, North and South and then it will start guiding.

Once it starts guiding, go to the dropdown menus and select Tools, Guiding Assistant.

Let it run for at least 120 seconds. Basically wait until the numbers in the highlighted box become stable or as low as possible.

Once happy its run long enough and stable, select STOP. Two buttons will appear in the blank space below RMS readins. Apply both buttons and close.

Start imaging.

If you feel the graph could be better, try increasing the exposure time from 3 seconds upto what ever. With my Mesu mount, I run at 6s and have a very smooth graph.

Thank you for the info Star will def take this on board. 

[Dan13]

19 minutes ago, Skipper Billy said:

You might find this document interesting - essentially its how to get the best out pf PHD2.

Second item down on this page. https://www.davidbanksastro.com/how-to

Thank you Billy I'll take a look 

[Dan13]

17 minutes ago, RolandKol said:

In my case with NEQ6 + 130PDS, guiding via EvoGuide +Asi120MM Mini

If I increase subs to 2-3s, I get results above 1.2 Total RMS...

1s produces around 0.7 - 0.8 Total RMS, which is enough for me, plus, calibration and PHD graph settling gets faster on 1s

Not everything works nice and as prescribed....

 

I'll will have a play arround and see what works best for me and my mount. After seeing all the info here I'm wandering if keeping it how it was may just do the trick but will def try the exposure time change and see what that brings.

[RolandKol]

29 minutes ago, Dan13 said:

I'll will have a play arround and see what works best for me and my mount. After seeing all the info here I'm wandering if keeping it how it was may just do the trick but will def try the exposure time change and see what that brings.

And do not forget to test how your guiding performs after the Meridian Flip.. Especially if you balanced it East Heavy and you do not adjust weights after the flip.
In my case, (it does not mean it will happen to you also), East Heavy was not an option... Yes, it had quite a better guiding results on the East side, but not on the West...
So I stayed with a completely balanced setup with a bit worse, but constant guiding results (around 0.7 - 0.8 Total RMRS) on Both sides of the Meridian, but without any manual adjustments, - means, I can sleep.

Before you push the guiding to the limits, - you should know values which are enough for your imaging.
Thanks to @vlaiv who has explained it to me few years ago, however I am not so bright and do not remember all of the maths
But as per your set up, - I am almost sure, even with 1 Total RMS error, - you will not notice much difference (or no difference at all) at the final image if you will compare it with 0.7 guiding.
(especially with a shorter subs, - somewhere below 3min)

Edited May 7, 2020 by RolandKol

[david_taurus83]

Your guiding is good. Dont concentrate too much on what the graph looks like. You will have good nights and bad  nights. Look at the stars in the subs.

[Dan13]

2 hours ago, RolandKol said:

And do not forget to test how your guiding performs after the Meridian Flip.. Especially if you balanced it East Heavy and you do not adjust weights after the flip.
In my case, (it does not mean it will happen to you also), East Heavy was not an option... Yes, it had quite a better guiding results on the East side, but not on the West...
So I stayed with a completely balanced setup with a bit worse, but constant guiding results (around 0.7 - 0.8 Total RMRS) on Both sides of the Meridian, but without any manual adjustments, - means, I can sleep.

Before you push the guiding to the limits, - you should know values which are enough for your imaging.
Thanks to @vlaiv who has explained it to me few years ago, however I am not so bright and do not remember all of the maths
But as per your set up, - I am almost sure, even with 1 Total RMS error, - you will not notice much difference (or no difference at all) at the final image if you will compare it with 0.7 guiding.
(especially with a shorter subs, - somewhere below 3min)

Thank you. I've not needed nor tried a meridian flip just as yet. 

I tried to image arround 4-5mins subs at present 

[Dan13]

20 minutes ago, david_taurus83 said:

Your guiding is good. Dont concentrate too much on what the graph looks like. You will have good nights and bad  nights. Look at the stars in the subs.

Thank you David. Stars look good, so I'm happy atm. I will change the exposure rate just to see but other then that by the looks of it , it could be a if not broke dont fix it sort of thing