ASI Air Guiding Struggles

[Todo43]

Hi all,

I recently bought an ASI Air Pro. Below is my gear for reference. I have been out imaging about 4 times with it and it has all gone quite smoothly except for the guiding. Before the ASI Air, I had so many nights where everything went amazingly with the guiding via the computer being under 0.5". When I now use the ASI Air, the lowest I can manage is about 1.75" for an extended period of time. It sometimes dips below 1" but only for about 15s. I have tried copying the exact settings from PHD2 to the ASI Air (Calibration Steps (ms): 1250, Ra Aggressiveness: 70%, Dec Aggressiveness: 100%). I then use between 0.5-1s exposure for the guide camera. When I do all that, it goes ecstatic and guides like crazy. Unfortunately, I don't have any screenshots of the actual guiding but I can get them on the next clear night.

Any ideas to fix this? guide scope is focused, the mount is polar aligned below 1'. Mount is balanced as well.

Skywatcher AZEQ5
SVBONY 50mm Guide Scope
ASI120MM


1600MM
Sharpstar AL-90R
EAF
EFW
ASI Air

[Nikolas]

How do you know the mount is polar aligned that well?Really need to see the screenshot of the guiding page to determine a few tings
Are you multi star guiding? if so 1 second guiding otherwise take it up to 2, you also need to adjust aggresiveness down for both, I use the default calibration for my setup (neq6 same guiding camera similar guiding scope) you will find that the guiding on the asiair is not as sophisticated as PHD2 even though it uses the PHD2 backbone so adjust a few things and recheck your balance.

[Todo43]

Hi Nik,

Here are a couple of screenshots of how crazy the guiding is.

I used the ASI Air Polar Alignment tool twice and got it below 1' each time.

I am multi-star guiding.

What aggressiveness would you suggest?

[Zuts]

Hi,

I am not trying to be critical but I have never seen such bad guiding. It's almost like the mount has horrible backlash in both axes, the scope is severely unbalanced or that maybe the mount head is not secure on the tripod and causes the setup to become non polar aligned.

You say you get good guiding with PHD 2. It is possible to use both the ASIAir and PHD. Why don't you do a run and when the guiding goes haywire, connect just the guidecam to PHD2 and see if it is still guiding like it was before.

Also with calibration you need to calibrate near the meridian. This thread may be useful. https://bbs.astronomy-imaging-camera.com/d/11318-guiding-asistant/18

[Todo43]

Hi Zuts,

I know! It has been absolutely terrible. Fingers crossed it will be clear tonight so that I can have a try using the computer to guide and ASI Air to capture. I hope it's not a mount issue. I really can't afford a new/better one. If it is, I don't know when it would have gone bad.

[Nikolas]

That looks like a balance issue in your dec axis
I need to see the whole image not just the graph a screenshot if possible.
Have you got dec on auto? it should be

[Nikolas]

Settling failed settling stared also indicates high clouds which can play havoc, I've seen that when I was imaging last weekend

[Todo43]

I find that the guiding settle ALWAYS fails. If that timeout is too short, I wouldn't know. Worked in PHD2 before

[ChrisD]

Same here, guiding settle fails.

Looking at the graphs it does seems like you have backlash in both RA and Dec. However, since it ran ok in PHD2 it may be just that the guiding rate is set too low on the Asiair.

Take a look at East Wind Astrophotography blog (https://eastwindastro.blogspot.com/2021/02/how-to-adjust-asiair-guide-aggression.html)

It covers the full setup of the Asiair guiding and parameter selection.

It could be worth forgetting the PHD2 settings and follow this blog post to setup the Asiair guiding. Maybe that will make a difference.

Chris

[Startrek]

Hmm......
Run the PHD2 Guiding Assistant for at least 5 minutes ( not 2 minutes )
It may give you a idea what’s happening with your mount
Polar Alignment
Dec backlash
And some recommendations
Worth trying .........