Horrible guiding results. Please help :)

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Sep 24, 2021, 3:26:12 PMSep 24
to Open PHD Guiding

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.


Sep 24, 2021, 4:03:00 PMSep 24
to Open PHD Guiding
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?


Sep 25, 2021, 12:10:10 AMSep 25
to open-phd...@googlegroups.com
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:
PHD2 works in units of arc-secs and all the default calibration and guiding parameters depend on the image scale.

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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Sep 26, 2021, 5:53:08 PMSep 26
to Open PHD Guiding
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.
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