Help With Guiding... Yet Again, Sorry

GiffS

I am terrible at forum searches and I need a nudge in the right direction in terms of settings for my AM5 running with an AA+. I am coming from running an AVX with my Air and I have no idea how to adjust the setting to get guiding to work. Got a good Polar Alignment but when I start guiding the Dec just goes nuts and never recovers. while RA plays nicely at 1.0" or below the dec will go to 114.0 always negative. I know it has to be something simple but I am stumped. I am running a ASI120MM Mini though and F4 30mm guide scope. I used this with the Air and my AVX just fine but on the AM5 it's a mess. I tried setting Bin 2, decreasing exposure time to 1 and .5 sec. messed around with aggression and changed calibration from 2000 to 1000 in all 3 boxes. Frankly I am just blindly hunting and it isn't working. Any help would be appreciated.

GiffS

I have plugged in the suggested starting values on Kevin's thread below and the Dec still dives to the negative, always to the negative.

eyecon

The dec number seems like your calibration is way off. Did you calibrate your guide scope setup in ASIAIR before guiding?

GiffS

My Calibration Step is set to 1000 ms down from 2000. should that be even lower? Or is there another setting I am missing?

w7ay

GiffS My Calibration Step is set to 1000 ms down from 2000. should that be even lower?

The PHD2 documentation is here:

https://openphdguiding.org/man-dev/Basic_use.htm#Automatic_Calibration

(See "Automatic Calibration.")

Tons of practical info on the web. Here is one:

https://www.astrohowto.com/how-to-do-a-proper-phd2-calibration/

If your mount is not well machined, try 12 to 18 steps to complete the PHD2 25 pixel movement.

Chen

GiffS

w7ay

I am using an ASIAIR which I know is using some sort of PHD2 but I it's a stripped down version so are there adjustments beyond what I see under the Guide Tab on the Air?

w7ay

GiffS are there adjustments beyond what I see under the Guide Tab on the Air?

Nope.

You need to switch to real software if you want more control of your equipment. Lots of people let the tail wag the dog, and continue to use ASIAIR even when it does not support what they need.

Chen

GiffS

Follow up question the ASIAIR did not do any sort of calibration last night. Should I force one somehow tonight?

w7ay

GiffS Follow up question the ASIAIR did not do any sort of calibration last night. Should I force one somehow tonight?

Are you on a tripod instead of a permanent pier? If so, you must recalibrate for PHD2 to get the correct RA-dec vs x-y pixel relatonship (what "calibration" does).

On ASIAIR, force it in the small guide window.

One possibility is that I could probably tighten up my focus on the ASI120MM it is a little sloppy but it worked fine on the AVX,

If you are using multi-star guiding, you need a perfectly focused image on a plate that is wide and completely flat. Use a decent guide scope with a field flattener, and with a camera that has a large sensor. Otherwise you will find ASIAIR multi-star guiding to go wonky after 1/2 and hour or so, and you are better off with single star guiding. I suspect that with your mount, 2-second exposures with single stars will do fine.

Make sure to follow the documentaton religiously, and calibrate near the celestial equator. Do not calibrate guiding at your target if your target is more than 20º or 30º from the equator.

As usual, ASIAIR is giving something really simple like autoguiding a bad name.

Chen

GiffS

NINA is in my future but just not right now. I need to get what I have working reasonably well which should be possible because after all everything is in ZWO's ecosystem. The mount, both cameras, the guide scope and the ASIAIR are all ZWO. Seems to me that there's something else I am missing.

Since the exact set up worked very well on my AVX I don't think it is any of the image train. One possibility is that I could probably tighten up my focus on the ASI120MM it is a little sloppy but it worked fine on the AVX,. Would slightly fuzzy stars cause a problem only in one axis, declination in this case?

It's as easy as 1 ,. 2... 3....right?

w7ay

GiffS

I wrote: I suspect that with your mount, 2-second exposures with single stars will do fine.

I didn't realize that you are using a ZWO mount. Can you go back to the AVX? The ZWO mount has all sorts of problems (see this forum and Cloudy Nights). Your problem could be one of these.

Since you are using the ZWO mount, I retract everything I have said (I had promised not to help with ZWO mounts).

Chen

GiffS

Thank you Chen, greatly appreciated. I have a ASI220MM on order so perhaps that will help. I could also move the current 120MM to a 50MM guide scope ( no flattener) if that might help.

GiffS

Well thanks anyway.

GiffS

Problem solved. Re-calibrated at the Meridian/Celestial Equator. Last night my target was the Soul and it is near Polaris right now. I tried to start guiding pointed at The Soul. I knew it had to be a stupid mistake on my part. Tonight after my PA and a return to Home, I slewed to M42 and ran a calibration there since it is close to the M/CE intersection. That did the trick. I am not at the level of accuracy I would like yet but I have something I can work with.

Thanks for the links Chen the info that pointed me in the right direction was in there. It seems even when you swear off helping AM5 users you still help them. : )