Advice for someone starting with auto-guiding? - Forums

Topic starter

Oct 2, 2021

Howdy,

I've been imaging for just over a year now and so far I've been very happy with my gear (IOptron Guider Pro + WO Zenithstar 61 + Nikon D5300 astromod)

But I've finally took the the next step in my AP journey...... Auto-guiding.
My setup is now improved with a WO uniguide 32, a ASI 120 mini, and the ASIAir Pro.

I gave it a try for the first time a couple of days ago with some test exposures on the Sadr region and I was super happy that I was successful on my very first attempt. It is really exciting to know that I'll be able to go past 3min subs.

I know there will be times where the guiding won't work as fine or that there may be ways to improves. So if anyone has pieces of advice about auto-guiding or things to look for or things to avoid please let me know.

Thx & CS everyone,
Nick

Engaging

wsg

Oct 2, 2021 · Edited: Oct 2, 2021

The asiAir Pro is designed to be fairly foolproof and indeed a press one button and go process. One bit of advise is to do a fresh calibration once you have your target framed, even though your prior Cal is saved I have found the guiding settles faster with a new calibration.
    1- set your guide camera gain to 50% of max gain and exposure to 2 seconds then "clear" calibration data
    2-calibrate guiding before starting Autorun
    3-start guiding mode in auto DEC with corrections switched on
    4-set both RA and DEC aggression to 50
    5-let guiding settle for a complete screen pass. it should be very good as it is but if RA is continually correcting and has a value over 70 or higher raise the RA aggression by 5 or 10. If your seeing is average or better this is often enough. If you are raising you RA agg, above 85 or so your seeing is shit or you have a setting that is not correct
    6- once your guiding is settled change your guide camera exposure time to 3 or 4 seconds
Let Air Pro chose the star to insure MultiStar guiding is activated. Let the guiding settle before deciding to make changes and make only small changes at a time.
There is an excellent write up about fine tuning asiAir Pro guiding here: https://eastwindastro.blogspot.com/2021/02/how-to-adjust-asiair-guide

scott

Helpful Supportive

Rob Calfee

Oct 3, 2021

The asiAir Pro is designed to be fairly foolproof and indeed a press one button and go process. One bit of advise is to do a fresh calibration once you have your target framed, even though your prior Cal is saved I have found the guiding settles faster with a new calibration.
    1- set your guide camera gain to 50% of max gain and exposure to 2 seconds then "clear" calibration data
    2-calibrate guiding before starting Autorun
    3-start guiding mode in auto DEC with corrections switched on
    4-set both RA and DEC aggression to 50
    5-let guiding settle for a complete screen pass. it should be very good as it is but if RA is continually correcting and has a value over 70 or higher raise the RA aggression by 5 or 10. If your seeing is average or better this is often enough. If you are raising you RA agg, above 85 or so your seeing is shit or you have a setting that is not correct
    6- once your guiding is settled change your guide camera exposure time to 3 or 4 seconds
Let Air Pro chose the star to insure MultiStar guiding is activated. Let the guiding settle before deciding to make changes and make only small changes at a time.
There is an excellent write up about fine tuning asiAir Pro guiding here: https://eastwindastro.blogspot.com/2021/02/how-to-adjust-asiair-guide

scott

Sage advice. I second this.

Olaf Fritsche

Oct 3, 2021

I recommend the same approach as wsg. with a small correction:
The iOptron Skyguider Pro corrects only in RA, not in DEC. Therefore you have to switch to RA only in the ASIair Pro

Nick Large

Topic starter

Oct 3, 2021 · Edited: Oct 3, 2021

Thanks guys for the thorough feedback. That is definitively very useful.

The parameters I used are mostly the ones by default in the ASIair app, like Aggressiveness.
The exposure time I used is what I found in various posts, and youtube videos. I'm still learning about various aspects of auto-guiding. For instance I still have no idea what the aggressiveness is. I'm guessing is somehow related to how frequently or how strongly the corrections are made. Something to learn more about because that seems to be something pretty important.

In my case, since I'm using a Skyguider Pro so I can only guide in RA and not in DEC as @Olaf Fritsche pointed out. But since I'll eventually (hopefully) get a goto mount at some point in time, that's still interesting to know.

I didn't' know about the multistar guiding. How do you do that? I haven't seen anything in the ASIair interface about this. Is is something done automatically? From my sole try It looks like it's just guiding on one star.

Thanks for the link @wsg . I'll definitively have a look.

Respectful Engaging Supportive

Olaf Fritsche

Oct 3, 2021 · Edited: Oct 3, 2021

For instance I still have no idea what the aggressiveness is. I'm guessing is somehow related to how strongly the corrections are made.

Exactly.

Olaf Fritsche

Oct 3, 2021

Nick Large:
I didn't' know about the multistar guiding. How do you do that? I haven't seen anything in the ASIair interface about this. Is is something done automatically?

When you go to guiding, just press the cross hair. Then the AISair itself looks for several stars suited for guiding.
Do not select a star by your own. The the ASIair uses only this single star for guiding.

Nick Large

Topic starter

Oct 3, 2021

Thanks @Olaf Fritsche. That's very helpful.
I did select a star on my first try. I did know what type of star to select but I wasn't aware of the multi-star functionality.
My bad :-)

Jure

Oct 26, 2021

Hi,

finally registered here after lurking for a while. About time, too!

I'm in the same boat as you are, Nick! I've been gazing at stars since 1977 but only now I have started imaging DSO. Planets were easy through my 250mm Newt compared to what I am experiencing now.

My imaging gear:
Star Adventurer
60mm APO F/6
AsiAir Pro
ZWO 30mm mini guide scope
ASI 120mm Mini guiding camera
Canon 80D

first off, AsiAir Pro is worth it's weight in gold for such a small and mobile setup. IMHO. And beyond, I guess.

Anyway, Nick, I suggest you install this superb utility: "PHD2 Log Viewer" which can be found here and examine your Guiding log! In the last two imaging sessions I ended up with 4 hours worth of images with elongated stars! After looking at the log it turned out that my aggression is way too low for SA! Which resulted in a "nice" sinusoid R.A. line, oscillating between +5" and -'5".

This is my M31 still with 70-200mm F/2.8 Canon lens - and Default AsiAir Pro settings, before I got "smart". Examining the PHD2 log I can even here see a slight sinusoid which means that SA has quite a severe periodic error.

In general, what I have gathered in the various forums and in my very brief imaging "career":
- play with aggression, increase it if needed, but do not overdo it. When you look at the guiding log the R.A. line should be straight (relatively, of course)
- decrease the interval in which corrections are sent if needed
- in bad seeing increase exposure of your guide camera to around 4 sec or so. AsiAir will take the average value. Or else guiding will be "hunting seeing"
- balance your imaging train so it is slightly pulling to the east and the R.A. gear will be engaged all the time
- if you are not dithering your images (which is otherwise strongly recommended for undersampled images), make sure dithering is OFF in settings
- look at your PA error in the log viewer, that's valuable information, too!

And since I'm a newbie at imaging myself, please feel free to correct me and/or add something I've missed. I could use some advice myself, especially about PA with AsiAir Pro. It's... erratic and I cannot rely on the results for some reason.

Other than that, I'm hopelessly addicted!

Cheers!

Helpful Engaging Supportive

Nick Large

Topic starter

Nov 9, 2021

Jure:
Hi,

finally registered here after lurking for a while. About time, too!

I'm in the same boat as you are, Nick! I've been gazing at stars since 1977 but only now I have started imaging DSO. Planets were easy through my 250mm Newt compared to what I am experiencing now.

My imaging gear:
Star Adventurer
60mm APO F/6
AsiAir Pro
ZWO 30mm mini guide scope
ASI 120mm Mini guiding camera
Canon 80D

first off, AsiAir Pro is worth it's weight in gold for such a small and mobile setup. IMHO. And beyond, I guess.

Anyway, Nick, I suggest you install this superb utility: "PHD2 Log Viewer" which can be found here and examine your Guiding log! In the last two imaging sessions I ended up with 4 hours worth of images with elongated stars! After looking at the log it turned out that my aggression is way too low for SA! Which resulted in a "nice" sinusoid R.A. line, oscillating between +5" and -'5".

This is my M31 still with 70-200mm F/2.8 Canon lens - and Default AsiAir Pro settings, before I got "smart". Examining the PHD2 log I can even here see a slight sinusoid which means that SA has quite a severe periodic error.

In general, what I have gathered in the various forums and in my very brief imaging "career":
- play with aggression, increase it if needed, but do not overdo it. When you look at the guiding log the R.A. line should be straight (relatively, of course)
- decrease the interval in which corrections are sent if needed
- in bad seeing increase exposure of your guide camera to around 4 sec or so. AsiAir will take the average value. Or else guiding will be "hunting seeing"
- balance your imaging train so it is slightly pulling to the east and the R.A. gear will be engaged all the time
- if you are not dithering your images (which is otherwise strongly recommended for undersampled images), make sure dithering is OFF in settings
- look at your PA error in the log viewer, that's valuable information, too!

And since I'm a newbie at imaging myself, please feel free to correct me and/or add something I've missed. I could use some advice myself, especially about PA with AsiAir Pro. It's... erratic and I cannot rely on the results for some reason.

Other than that, I'm hopelessly addicted!

Cheers!

Hi Jure,

Sorry for the late reply. It looks like I missed the notification when you posted.
We have very similar gear, that's nice.
The tips are really useful, thanks. I've been imaging with auto-guiding for about a month now and I think I'm starting to have a descent grasp of it. I'm routinely guide (in RA only) between 0.5 and 0.8". From what I understand this seems to be pretty good.

I also think I'm balancing my setup much better now. For the PA, I'm using the PA routine in the ASIair app. That's pretty awesome, I can routinely achieve a PA with a total error of 20" or less, and I've definitively seen an improvement on the stars.

Thanks for the link to the Log viewer, that's seems pretty cool. I'll play around with it and see what I can learn from my previous guiding sessions.

I, too, am hopelessly addicted. :-D

CS -- Nick

Respectful Concise Engaging

Jure

Nov 9, 2021

Hi Nick,

no worries…

You've managed to tame the AsiAir! 0.5 to 0.8 is great! Now my fingers itch, but I am clouded out, weather just won't cooperate! And no clear skies in sight in the near future.

20" PA? I must be doing something wrong… can you please share your routine? I tried with SA drive switched on and off, I put it in the "home" position as accurately as I could but somehow, I cannot get under 1'. Either it is 1' to one side and after a really tiny adjustment, it is 1' or 2' to the other side. I really don't understand it. Something is not right. By the way, my polar scope is calibrated.

In the meantime I got hold of a few minor upgrades for my StarAdventurer over at astrokraken.fr. Declination "setting circles", so it will be easier to position SA at the same spot as on the previous imaging session. I found out that in AAP you can save your object which you are imaging and it will remember the exact coordinates. So, comes the next night it will guide you to this same spot when you select it. I haven't had the chance to try this yet, but if this works, well, it will be much easier to image the same object on successive nights! Great for us without GoTo!

Cheers!
Jure

Helpful Respectful Engaging Supportive

Jay Stanley

Dec 7, 2021

Only way to fly in my neck of the woods. Automation at it's best. Thanks Scott for all the help!!