PHD2 Guiding Calibration Walkthrough

[@sdevine49]

This was amazingly helpful. Honestly, I didn't understand what to expect with calibration, and this clarified everything.

[@AstroVagabond]

Glad I could help. 👍 I'm back imaging after resolving an issue with my autofocus set up which I created. I will share that mistake in a video soon.

[@MateuszLibner]

hey, I have the same problem as you in the Dec axis, I am in the Ra axis, the graph jumps all the time and sometimes it's a total exaggeration. solved the problem?

[@AstroVagabond]

I'll review what I said in the video later today and then come back here and comment. Thank you for asking!

[@MateuszLibner]

@@AstroVagabond Hey, and?

[@MateuszLibner]

@@AstroVagabond pls help me 😕

[@AstroRef68]

Hi . Very good tutorial. I don’t see pulses on my phd and keep stoped guided Any idea ?

[@AstroVagabond]

Sorry Astro for the late reply. If you have not yet figured it out can you share a bit more about your setup?

[@jodyschultz5870]

Just what I needed, how to force a recalibration. Thanks.

[@AstroVagabond]

You're welcome! Thank you for taking a moment to say hello Jody!

[@2badger2]

Bruce Waddington, who runs PHD2, has some good video about PHD2. How good does polar alignment have to be, what numbers shouldn't you touch ...

[@AstroVagabond]

Good call out! I've seen those videos and agree they are worth the viewing time. 👍

[@No_no83]

Hi Bill. My guiding with ST4 cable always worked great. I've always had issues with Pulse guiding. During calibration I always get the message that star movement is too low or not enough.I never figured out what was the problem. If you could help. Thank you.

[@AstroVagabond]

Hi Jean if you can share more details about your mount and guiding software that may help generate responses. Otherwise if you use PHD2 and have not reviewed this page it might be a place to start: openphdguiding.org/man-dev/Trouble_shooting.htm

[@JVRost]

In addition to the obvious reasons for backlash along the DEC axis, you have in the settings on the brain-guiding tab - the calibration step value is 2650 ms - this is a lot, set at least 750 ms. Also check the stellar velocity settings in the EQ Mod, it should be 0.9. Increase the gain of the guiding camera as well. You have it 48 by default, set it to 90, if you made a library of dark frames, then everything will be fine. 2.0 seconds is a lot for your mount, you can see for yourself that 1.5 seconds is better. But of course, you need to start with the mechanics of the mount. Hello from Ukraine.

[@AstroVagabond]

Hello Just Volkov thank you for taking a moment to view and comment during your challenging times. Stay safe. My father's parents immigrated to New York Ellis Island in the early 1900's from Ukraine. I appreciate your input. ~ Bill

[@JVRost]

@@AstroVagabond The land of Ukraine is not only rich in wheat crops, it gives birth to kind and intelligent people. Your parents were smart)) I am very pleased to hear your story. Good luck and good luck to you and your family.

[@JVRost]

@@AstroVagabond The land of Ukraine is not only rich in wheat crops, it gives birth to kind and intelligent people. Your parents were smart)) I am very pleased to hear your story. Prosperity and good luck to you and your family.

[@paulwilson8367]

Thanks for vid. I used to use ASAIR Pro and it made it very easy to guide. Now using NINA and PhD 2. Having a rough time. I got a new mini guide cam like yours. I also use that same camera from a previous guide scope. Focusing it was difficult but last night I thought the stars looked adequate to guide. But when I started it running RA line went one way and Dec line went the other. I thought, oh it needs now to be calibrated. When I tried to start that, it said that there weren't enough stars in the area (Hercules Keystone) to calibrate and I should let it slew closer to the equatorial horizon. That was below my local horizon and when I went outside to look, scope was pointing at the ground. I couldn't get anything going at all. No guiding at all. Today if I have a clear hour or 2 I will try again, it shouldn't be so difficult! I will recheck my setup connections. Today I will also check the belt on my EQ6-R and see how loose it feels. I've had this mount for 3 years and of course there is no place to take it for service. I don't know what else to try.

[@AstroVagabond]

You are welcome and thank you for sharing your current experiences. Much appreciated.

[@JonDoe-se3mi]

I find when the guidescope is a little out of focus it finds the stars easier and doesn`t effect guiding...

[@AstroVagabond]

Thank you for taking a moment to share the excellent tip! Much appreciated. 👍

[@bharathraj5768]

Thanks Bill for the mention

[@AstroVagabond]

You are most welcome Bharath. I appreciate your help and taking time to comment! 👍

[@bharathraj5768]

@@AstroVagabond it’s been a while since I saw a new post Bill.. hope you’re ok over there.. tc

[@AstroVagabond]

@@bharathraj5768 Hi Bharath all is good here hope same for you! I'm uploading now a video on Atmospheric Seeing and Transparency waiting for it to finish HD processing before I publish. It may be to beginning for you but I thought I would start to share what I felt I needed to know to make a good decision on purchasing a dedicated monochrome camera. This is the first of maybe three videos. Other than that it has been raining and cloudy so I can't capture any video footage on the features in Astrophotography Tool while I'm imaging. How have your skies been?

[@febsat]

Great information for me, as I'm just getting set up to start using PHD2. Thanks for creating such an interesting article.

[@AstroVagabond]

Glad I was helpful febsat. And thank you for dropping into the channel and taking time to comment. Hope you drop back in to update us on your progress with PHD2. 👍

[@goatsuukerhill]

Thanks Bill. Phd2 has not improved my tracking at all. I only get 40% of my 120” frames that are usable. I have run phd2 on 8 sessions. 4 Guiding assistant runs have not improved guiding. I have redone polar alignment many times and it is always very close. What are the polar alignment error limits that guiding assistant reports? Got any suggestions for me to get better tracking? AVX, SV 130, eos800d, 50mm sv guide scope, asi290mm mini guide camera, usb connection. Thanks Warren

[@AstroVagabond]

Hi Warren my first thought at this point is to add up the total weight of your gear that you are mounting and compare that to the load capacity of your mount. For example I looked at a Stellarvue 130 and it weighed in at 21 lbs. It has two mounting rings that weight 1.4 lbs. each. You camera is 18 ounces. A guide scope is about 1 lbs. Why I mentioning this is I'm trying to figure out for myself, where my mount has a 30 lb. payload, how much can I actually place on it and still get acceptable performance. I want to purchase a second scope and need to understand actual limitations of my mount versus advertised payload specification.

[@goatsuukerhill]

@@AstroVagabond my imaging gear weighs 27#. With the FR/FF it weighs 29# The avx payload is 30#.

[@goatsuukerhill]

So your point is well made, my rig’s weight may be the problem. I should test the guiding with a much lighter set up. But I dont have one.

[@AstroVagabond]

Can you remind me the length of your exposure? What does PHD2 report for total error in arcseconds? I used the astronomy.tools CCD suitability calculator entering your scope and camera and it shows they are a good match with a pixel resolution of 0.84"/pixel.

[@goatsuukerhill]

@@AstroVagabond I get 40-50% usable frames at 120”. At 60” I get about 70%.

[@apiaristicone9585]

thanks for the video Bill, very helpful

[@AstroVagabond]

You are welcome! And thank you for dropping into the channel and taking tome to comment. 👍

[@darrenwarne9005]

The backlash is why the DEC graph is bouncing so much. Going to have to check the mount for adjustments

[@AstroVagabond]

Got it and thanks again Darren. I knew when I was purchasing the HEQ5 without the mod I might have some challenges. Much appreciated! 👏

[@jimoray3]

Well Bill, the best I could do was to get a monoscope for my iPhone 11Max Pro but I’ve got a 3 axil Gimbal with 4K on my drone but you are out of my league right now but if I still keep watching your videos, I bet I can be convinced. Lol

[@AstroVagabond]

Jim you do have a great piece of property up in elevation that may be a prime spot to image from. I don't want to egg you on but just saying! 😀 Hope all is well in the Rayzone Jim! Keep up the great work with your videos. 👏👏👏

[@kawandabe]

The RA is not to bad but the DEC is really all over the place. You should follow the instructions and put the pulses on 'north" in the brain > Algoritms > Dec Mode Guide and set to North as advised by guiding assistance. You have to much backlash on DEC (typical issue with most mounts) and as a result, changing directions via pulses in PHD2 is generating overshoots followed by corrections. When you only allow pulses in one direction (do guiding assistance after every new polar alignment), you don't have backlash issues because your direction of DEC doesn't change. Also, your guidescope doesn't need to be very sharp. It's even advised to be a bit out of focus. So consider to remove the DEC backlash from the mount because it's quite easy to do yourself and this will improve your guidance a lot. With your mount you should be at around 1" max of total error instead of above 2". With a short tube, this is not an issue but when you go to higher magnifications, you will run into issues with bloated stars. Clear skies.

[@AstroVagabond]

Thank you henk for the great feedback. 👍 Next clear sky night I put into practice your recommendations!

[@scignosis]

that gong..almost lost a pair of underwear

[@AstroVagabond]

LOL!