Horrible guiding results. Please help :)

[Chris]

https://openphdguiding.org/logs/dl/PHD2_logs_LpAw.zip

This is my first time guiding with this gear setup:

OTA Orion 8" astrograph

Atlas EQ-G

Guide scope Orion 50mm

Guide Camera ASI224MC

Imaging Camera ASI1600MM Pro

Attached is an screen shot of the guide graph. I let PHD2 autoselect the star. I was not on a hot pixel. My polar alignment was spot on. I checked it then stopped and double checked it again later in the night and i was still aligned. At one point I did have an issue with my mount losing power and the mount stopped tracking in the beginning of my session. I was able to resolve it and the last 2 1/2 hours of my session I did not lose connection with my mount again. My RA and DEC look like they're making HUGE adjustments. It is also taking a solid 10 minutes + for PHD2 to calibrate and begin guiding. I appreciate the help.

[Chris]

I was just told in the cloudynights forums that my Focal Length of my guide scope was wrong. I had it set to 50mm when it should have been set to 162mm. Do you think that could lead to such bad guiding?

[bw_msgboard]

Yes - it's garbage in, garbage out.  To understand why this has such a big effect, read the appendix section called Image Scale and Measurements in Arc-Secs in this document:

 

https://openphdguiding.org/tutorial-analyzing-phd2-guiding-results/

 

PHD2 works in units of arc-secs and all the default calibration and guiding parameters depend on the image scale.

 

Bruce

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From: open-phd...@googlegroups.com [mailto:open-phd...@googlegroups.com] On Behalf Of Chris
Sent: Friday, September 24, 2021 1:03 PM
To: Open PHD Guiding
Subject: [open-phd-guiding] Re: Horrible guiding results. Please help :)

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[Chris]

I also realized that my guide speeds were set the to default 0.1x sidereel in EQMOD. That would explain the huge corrections it was making and I was jumping all over the place.