Autoguiding with PHD2 - Theory, Setup and Operation

As your astrophotography skills develop, there comes a point where you want to take longer exposures to go deeper into Deep Sky objects to acquire more hours of total exposure time without clobbering your hard drive too badly. Doing this pushes your tracking mount harder and exposes its limitations. That's where auto-guiding comes to the rescue! In this tutorial I explain the theory behind auto-guiding, show you what hardware you need to set up, and show you how to install the software required. I then demonstrate how to set up the PHD2 autoguiding for the first time, and how to calibrate and get auto-guiding.

[@kilohertz684]

Hi Martin, I have been struggling with PHD2 for 2 evenings now in freezing weather, trying to get it to work properly, I am so glad I found your tutorial, it's very easy to understand and I'm now going to look for more on your channel. Thank you!

[@martinsastrophotography]

Thanks for letting me know my tutorial helped you out. Much appreciated. Clear skies!

[@secretstill]

Thanks Martin. Easily the clearest explanation of PHD2 set up I have seen. I like your straightforward style and the way you don't skip over the finer details. Great work!

[@martinsastrophotography]

Thanks so much for your positive feedback Mark. Clear Skies!

[@daansteegmans]

Guiding explained from start to finish for dummies. Just what I was looking for. Thanks Martin!

[@SKYST0RY]

I loved this. One of the most thorough PHD2 tutorials I've seen.

[@martinsastrophotography]

Thank you!

[@EMILIONAMUR]

Thanks a lot for this video. You are the only one explaining how to use phd2 step by step, which was very useful for me, since I am learning everything alone from zero!

[@johnringo1271]

Video was good, however…reading through the comments and seeing all of the questions you’ve taken your time and effort to reply to is remartinable. Subscribed.

[@martinsastrophotography]

Thank you John. That is much appreciated. Let me know if you have any questions!! Clear Skies.

[@TheSplashingPirate]

EXACTLY what I’ve been needing to understand! Thank you AGAIN!

[@paulwhitton957]

Fantastic explanation Martin once again with your videos. I do appreciate the effort you put in to produce such clear and concise tutorials. Thank you.

[@martinsastrophotography]

Thank you so much Paul. Really appreciate your comment. Clear Skies!

[@condensermike]

Great vid and right on time as I have some auto guiding equipment coming in the post today! Thanks!

[@martinsastrophotography]

Cheers Mike!

[@mathjennekens6153]

Thanks Martin, extremely useful intro on how to install and run a mount using PHD2. Very informative and well done!!

[@martinsastrophotography]

Many thanks for the positive feedback! Clear Skies.

[@user-ig1iu3mx9k]

Thank you, Martin! You helped me out with the number of coarse Knob turns on the Edge 11 a while ago... and now this tutorial has really helped me again... Thanks again for an excellent tutorial!

[@siegfriednoet]

Very well explained Martin, it's easy if you know it, for me it's still a steep learning curve, so all these kinds of video's like this one are welcome

[@martinsastrophotography]

Hi Siegfried. Thank you so much for your positive comments. This video took a long time to create so it’s really nice to hear that it’s appreciated. Clear Skies!

[@oakleywindowcleaning]

I guided using PHD2 two nights ago for the first time, since watching your video. Thankyou.

[@martinsastrophotography]

I remember how exciting it was to get it going for the first time. Well done. I hope the video helped in some way. Clear Skies.

[@warrenhill8022]

Thanks Martin for an excellent presentation and explanation of the finer points of PHD. Very helpfull info

[@martinsastrophotography]

Thanks for the positive feedback Warren. Much appreciated. Clear Skies!

[@martinfish4079]

Fantastic video - thank you for the clear step-by-step explanation!

[@martinsastrophotography]

Glad you liked it!

[@randytalley7177]

YES! Sometimes I feel if I watch ONE more video that ends up being a waste of my time....but this one was spot on. Thank you Martin. As a beginner, the more I read, watch, the more overwhelmed and confused I get. This has at least cleared up many of my issues. I also REALLY appreciate the schematic of how the cables work from the devices to the laptop. Good stuff.

[@martinsastrophotography]

I know just what you mean Randy. At the end of the day, doing it yourself and making mistakes along the way is the best way to learn. Unfortunately there are a lot of conflicting opinions out there that make it harder, especially for beginners, to figure out what to believe. My videos are all based on what I have learned by doing Astrophotography and doing what you are doing...researching online a lot. Sometimes others do things differently to me and that’s fine. I simply show what works for me. Have you taken the plunge and bought a tracking mount? If so, learning to master that is by far the most important first step of the journey. I bought a tracking mount long before I bought a telescope, and have never regretted that decision. Clear Skies!

[@davorfliker2362]

Dear Martin Thank you very much. I will go throught your instructions tommorow evening as today seems that will be cloudy. Will replay as soon as I get feed back from the your procedure Clear sky Davor

[@peterschmitz4308]

Many thanks, Martin. You got me up and running on my first night out!

[@martinsastrophotography]

That’s great to hear Peter! Thanks for taking the time to let me know. Clear Skies.

[@Nick-we7lf]

Most excellent and clear explanation on the topic. Thank you for a great video.

[@martinsastrophotography]

Thank you Nick. Appreciate you taking the time to comment. Clear skies.

[@MADHIKER777]

Crystal clear explanation! Thank you!

[@KostasPatmanidis]

Another great video Martin :)

[@wanderingbrummie]

Really helpful, thank you.. I’m thinking of adding guiding to my small refractor setup, this has cleared up a lot of my questions

[@martinsastrophotography]

Thanks for the great comment. Much appreciated. Clear Skies!

[@vjcaiozz]

Very good instructional video. Thanks for providing such insightful information.

[@martinsastrophotography]

Thanks Version nice. Glad you liked it. Clear Skies!

[@drandrewclarke]

glad I found you. very clear and easy to understand tutorial

[@martinsastrophotography]

Thank you so much!

[@Arcteek]

Excellent video, thanks!

[@briansnell9179]

Another well presented video Martin. Although I have been using PHD2 for over 3 years now, I did still pick a useful bit of info on off axis guiding, which I haven't tried yet and it may be a mod I try some time in the future. Cheers.

[@martinsastrophotography]

Thank you Brian. Glad there was something useful in there for you. Clear Skies!

[@OutlandishJourneys]

Another cracking video, Martin! Cheers and keep up the great work! :)

[@martinsastrophotography]

Thank you so much. Really appreciate the comments!

[@ASTROindi]

Very helpful Tutorial, thanks for making it. Clear skies

[@martinsastrophotography]

Thanks for the great feedback! Clear Skies to you too.

[@davekemp750]

Just what I was looking for, thank you. New sub :)

[@martinsastrophotography]

Thank you Dave. Glad you liked it. Click the bell for notification when I release new videos. Clear Skies!

[@MarvelousLXVII]

Great video as usual.

[@martinsastrophotography]

Thank you!!

[@kayedsss]

Thank you very much!

[@jonrobinson1026]

Many thanks. We're pretty much bang on the Meridian here in Lliber 0.06 East ish.

[@martinsastrophotography]

I think you meant the Greenwich Meridian, which is 0 degrees longitude. Everyone is “bang on the Meridian”. The Meridian is the (circular) line from North Pole to South Pole via your location so it goes directly overhead you wherever you are.

[@robertarmstrong9406]

Very nice job Martin. If you ever do a follow-up. The dark library and Acquire Master Dark frames for Bad Pixel Map Calculation. Maybe a nice area to start.

[@martinsastrophotography]

Thanks for the feedback Robert. Clear Skies!

[@SuperKevinFS]

I would apprecaite some advice please. I am calibrating PHD2 pointind at the intersection between the CEL and the Meridian. Getitng calibrated run it for 10 mins then let the GA run for 5 mins no issues. I then park my scope back to the home position pointing at the NCP and the guding does not work. Says i need to be near the celestrial. This is an on going issue can any one help me with this one. If i try to force a calibration at the home position there is not enough movement and get the star could not be moved enough thanks so much

[@AstroRef68]

Hi I’m have hard time to see graphi showing up and after fiew minutes stopes guiding I’m not using sg4 cable with mount i assume you are not using st4 cable I’m not sure how to calibrate it maybe that’s why I have trouble Thanks

[@cyrusparrsi2583]

Hello and thanks for the informative video. Could you tell me how you connected a guide scope to your canon lens? Also how to attach the lens to the mount. Thanks

[@martinsastrophotography]

Hi there. Watch this video!! kzbin.info/www/bejne/Y4GYg3Z4ZrFmaMU

[@fromupthere.2209]

Thanks ,mate, just using it for the first time..had totally missed the eqascom drivers..would have been tearing my hair our wondering why it wouldnt work..

[@martinsastrophotography]

Thanks for your comment. Glad it was helpful. Clear skies!

[@deep-skyastrophotography475]

Hi Martin, great video and very informative. I have a question if you have a quick moment. I have an HEQ5-PRO, and using APT and Dithering. I keep having a settling timeout error and it's on the declination according to the graph in phd2. Did you ever have any similar issues? Thanks

[@martinsastrophotography]

Thanks for the feedback. I have not seen this error myself. Here are my thoughts.... Have you calibrated in PHD2 successfully (you can review the calibration graph to see if it is a nice pair of lines at right angles to each other)? Is guiding then active (PHD2 displays "Guiding" at bottom left)? Have you enabled mount guide output? If the Declination does not settle it either means 1) the Calibration is not good, 2) Dec corrections are not being sent or 3) the mount is not performing the Dec corrections when commanded to. 3) can be ruled out is the Cal graph looks normal since correction pulses must move the mount during calibration for a successful Calibration.

[@markkorzen8523]

I got into this hobby last year in a big way. You're the first influencer, I've come across that is likely on the same brain wave as me. And, I do think of myself as a, "Polymath in the field of statistical deviation analysis." Right down to thinking about any given observation, in terms of normalized statistical distributions, and all that entails." That is, "The Applied Physics of the solid-state MAKING observations. (idmw)". That is, "An innate ability to fathom the Mathematical Abstractions" for relationships, "In terms of visualization." Case in point. I am not 4 mins into your vid and I am already up and running... By taking your formula for the, "Minimum guide scope focal length ='s. ". Look if..., "I can't flesh out my thesis in a five minute presentation then, 'I will be a humble polymath.' ". What I will be presenting is that, "By algebraically rearranging the f(x). Something useful, 'May comes of it.' ". And, I do mean with all, "The foresight of you being q.e.d. on my thesis. ". Thus towards, "The ability to track on this unity pixel." Yes... I have already fathomed that, "This applicability is very much weighted by, all the other introduced errors of the hobby. ". Still, my position will be, "Do I have something to say about this unity pixel that is inherent of the equation. ". A positive response, "Will start the ball rolling. ". Sincerely, Mark

[@martinsastrophotography]

Words fail me Mark...but I'm so glad you liked it! Clear Skies.

[@markwelsh9068]

@@martinsastrophotography Fail me too! WTF was he on about? 🙂

[@febsat]

Thanks for the tutorial Martin. Very easy to follow. I have been using PHD2 for about a year now, including multi-star guiding and find that it works very well. One thing that I have not seen on any of the PHD2 tutorials is discussion related to focusing of the guide scope and what is the proper sharpness of the guide star(s). Could you comment on that? Cheers.

[@martinsastrophotography]

Hi there. Thanks for your feedback. In my experience it is not essential to achieve perfect focus on the guide scope. PHD2 worked very well with slightly refocused stars. This is because it uses an algorithm to locate the centroid position of clusters of brighter pixels. I have seen claims from others that it could even be beneficial to be a little out of focus, but I have not seen any evidence to confirm (or disprove) that.

[@febsat]

@@martinsastrophotography Thanks for your quick reply. Cheers.

[@charlesbrantley5773]

Where can I get these class online

[@mobi_61]

Nice guide video. Can you show, please, how cable needed for connecting camera with mount and computer. And How can I do it? Software is one part it, and connection hardware is two part. In much videos are showing one or second, but not all completely process. Thanks for your video.

[@martinsastrophotography]

Thank you. You need to connect the guide camera to the computer and also connect the mount to the computer. Do not connect the guide camera to the mount!!!! I hope this helps.

[@taraswertelecki3786]

One question I have about the auto-guiding. How do I connect the computer to the mount? I have a Celestron AVX mount.

[@martinsastrophotography]

Astroblender has done a video on that here… kzbin.info/www/bejne/o3Xbm5l9n9edfq8

[@2badger2]

I control my Sirus EQ-G mount using Stellarium, the cable goes from the mount though the SynScan hand controller into my PC. Can that cable be used by PHD2? Thank you

[@martinsastrophotography]

I assume you have ASCOM and EQMOD installed? If so, then yes I would expect simultaneous connection to PHD2 to work fine.

[@phutchis]

I use the Star adventurer, canon 7dmk 2 and Tamron 150-600mm lens. I guide with ZWO mono camera and 120mm focal length ZWO guide scope. Sometimes (not always), the guide star drifts off from the cross hairs usually to the right. I also dither. Guiding graph is fine and final images are ok too. Is there a pointer you could suggest that is causing this slight drift? Tonight I will be trying out the multistar guiding option. Thanks in anticipation Paul

[@martinsastrophotography]

Hi Paul. Suggest you run the Guiding Assistant (under the Tools menu) for 2-3 minutes and see what happens. While this is running, corrections to the mount are disabled. Look to see if there is an obvious drift in either RA or Dec. (You said it drifts “right” but I cannot tell if this is RA or Dec as I don’t know your guide camera orientation). If drifting in Dec then probably a polar alignment error. If drift oscillates in RA look the see what the oscillation period is as that is a major clue to the root cause. Let me know and I’ll try to help you diagnose it. At the end of the day if your guiding performance is ok and your images are ok too, then there can’t be a major problem.

[@Ken_James_SV]

Good clear explanation, but you fail to mention the easiest setup. Skip the need for EQmod and it's associated cable from the computer and simply run a short cable from the guide port on the guiding camera directly to the Guide port on the mount. In the setup window select 'On-Camera'. Done. Works exactly the same but without the need for EQmod or a long cable.

[@martinsastrophotography]

Thanks Ken. I deliberately do not mention this approach. There is a lot of material online steering astrophotographers away from the connection method you describe. It is generally considered better to have the PC connected to the mount (via EQMOD) and to the guide camera, and to then use PHD2 to communicate with both. I cannot recall the details why this is preferred, but it makes sense to me that guiding corrections are sent by the PC and not the guide camera. That way we can see what is going on. Connecting to the mount via EQMOD brings other benefits such as interfacing to Stellarium, Sequence Generator Pro and other Astrophotography suites. Clear Skies.

[@Ken_James_SV]

@@martinsastrophotography - Martin, you are way off track with thinking "it makes sense", because technology has moved along. Proof is in the practice. The On-Camera method is widely used and is still controlled by the computer through PHD2. There is no difference in control of guiding. The original EQmod interface had to be used before guide cameras came out with ST-4 guide ports on them. Look back at the old cameras we used to use: Phillips TouCams, analogue security cameras, etc. They had no Guide Port. The Orion Starshoot Guide camera was about the only camera with an ST-4 port back then, then eventually other cameras also added the port to allow a simple On-Camera to Mount connection. Now they all have the port. The Guide camera isn't sending any signal, It is only a Junction between PHD2 and the Mount. You still have to run a cable from the camera to the PC to guide, but not all the way from the PC back to the camera via EQmod. Using On-Camera doesn't prevent PHD2 from interfacing with Stellarium etc. In fact, I interface with Cartes du Ciel. The only way to lose that interface is by Guiding from a separate computer. Every Astrophotographer in our club uses the On-Camera method. I only know of a few people still using EQmod. Try 'On-Camera' for yourself and you will see no difference to EQmod. Just easier cabling and no need for EQmod. 👍

[@martinsastrophotography]

@@Ken_James_SV Thank you so much Ken for putting me straight on this one. While I try to give good advice it can only be based on what I know at the time, and like everyone else I am always learning. I will try out what you have described. Thanks again.

[@Ken_James_SV]

@@martinsastrophotography I enjoy your tutorials. They really help many people. We are always learning. I know I am, and sometimes even the teacher 😁 I hope you have success. Glad to assist 👍

[@jonrobinson1026]

Just about to follow your PHD tutorial. What first. If I choose Andromeda as my target for an imaging session. Do I slew the mount to it first and then choose a nearby star for PHD 2 to begin tracking Andromeda? Many thanks if you can help.

[@martinsastrophotography]

It’s best to choose somewhere about 30 degrees above the horizon to the east or west (choose same side of Meridian as your intended target) to do the calibration of PHD2. Then slew to your target, frame it and start guiding.

[@KrzysPioro]

Thanks Martin. Do you think that zwo mini guidescope 32mm/120 with svbony105 will be good enough for my TS photon 150/750 f5 newtonian? I know 50mm will be much better but...skinny wallet, regards from Poland. Kris.

[@martinsastrophotography]

Hi there. Yes, that should work OK, although you did not tell me which main imaging camera you are using and the pixel size of that camera is involved, I assumed 3.75um. You can use the calculator on my website martinsastrophotography.com/calculator-tools/ to compute the minimum guidescope focal length required. Using 3.75um as the main camera pixel size, this gives 60mm as the minimum guidescope focal length, so it looks like you are fine. If your concern is the small guidescope aperture, I wouldn't worry, as you can always use a longer guidescope exposure time if you need it.

[@refetastro]

Excellent video Question: Can I run guiding camera being attached to guiding port on the mount but with out connecting the mount to pc? Because I’m missing the cable . I tried last night and I couldn’t make it work guiding .

[@martinsastrophotography]

You can, but this is not the recommended method. It is better to connect the guide camera and the mount to the PC. I recommend you buy the missing cable.

[@refetastro]

@@martinsastrophotography I agree

[@TheSplashingPirate]

Thank you for another great instruction video. Could you explain using PHD2 in conjunction with a planetary program like Starry Night? In reading instructions on EQMOD, it says That after I complete the installation of the EQMOD ASCOM driver, it should show in the planetary program. So, do I use PHD for the guide scope but then run something like Starry Night for the rest?

[@martinsastrophotography]

Thank you. If you are guiding using PHD2 and using a planetary program (Stellarium etc..) to slew to targets, then you will need to stop guiding before slewing to a new target, otherwise PHD2 will sound an alarm when you slew to a new target as it will lose its guide star. If you forget to stop PHD2, and the alarm sounds, simply stop the guiding, start the camera streaming again and then, when the slew is complete, you can select a new guide star and start guiding again.

[@TheSplashingPirate]

@@martinsastrophotography I’m so grateful for your guidance! Thanks AGAIN!

[@vcotta2012]

What's the guide speed on the ioptron Skyguider Pro?

[@martinsastrophotography]

Default is 0.5x but you can set in anywhere in the range 0.1x to 0.9x

[@douglassmith1215]

One thing about PHD2 that I've noticed is that by default, it does not do a new calibration with each new imaging session. The assumption it makes is if you chose a saved guidescope and camera configuration, you want to use the last calibration for that saved combination. This is convenient if everything remains exactly the same, but of course things do change. For example, backlash can change for a number of reasons. Or the rotational orientation of the guidescope camera could change, which will totally confuse the program. If you want to clear the old calibration and do it again, you need to go into the advance settings. I suspect reusing outdated calibration settings can potentially cause a lot of guiding problems.

[@martinsastrophotography]

Hi Douglas. There is an option in the ‘brain’ settings to restore last calibration or not. You can also hold the shift key down when you click the green guiding button and it forces a new calibration to start.

[@douglassmith1215]

@@martinsastrophotography Yes, the "brain" or advanced settings have restore last calibration as a default, which I suppose is convenient, although perhaps not the best choice. A suggestion for a future video would be to dig into all the options possible with PHD2. I find the polar alignment function to be really helpful.

[@martinsastrophotography]

@@douglassmith1215 Thanks for the suggestion. I will add it to the list!

[@crm114.]

Excellent review. Thank you from an astrophotography beginner. Any downsides to off-axis guiding?

[@martinsastrophotography]

Thanks Cliff. Yes. The main issue is that if you are using a long focal length telescope then you will see fewer stars and in some cases may even struggle to see a single suitable star for guiding. With my 800mm Newtonian this has never been an issue but with a Schmitt Cassegrain Telescope (SCT) with upwards of 2000mm focal length it will become an issue. You would then have to consider rotating the scope to get a suitable star into the field of view of the OAG which is a pain but do-able. Note that in my experience stars look rather distorted using an OAG and it is hard to get them in perfect focus, but these issues do not cause problems with guiding so they are not particularly important.

[@EMAINC3]

@@martinsastrophotography Thanks for the tutorial - will be most helpful getting started with PHD2. Just curious - would you have a recommendation for a guide scope/camera combo that would be appropriate for an 8 inch SCT with a focal length of around 2000 mm? Thanks!

[@martinsastrophotography]

@@EMAINC3 Thanks for your comment. I use the QHY5L-II-Mono guide camera, but this has quite a small sensor so is best used with shorter focal length guide scopes like the 9x50 that comes with so many telescopes. Now you have quite a long focal length on your main telescope at 2000mm. This demands more sensitivity to movement than for shorter focal length scopes. But there comes a point at which the seeing becomes the limiting factor. As far as a recommendation goes, it does depend on your budget. If you are on a tight budget then I would start with a low cost 9x50 guidescope (180mm focal length) and the QHY5L-II-Mono and see how you get on. You may later decide to swap out the guide scope to one with around 250mm focal length which is better matched to your 2000mm main scope focal length. If budget is not an issue, you could consider going straight in with an off-axis guider with a prism around 8mm square, like the ZWO OAG V2 and a guide camera that has a large sensor (so you can see enough stars) like the ZWO ASI174MM Mini (11.3x7.1mm sensor). There are so many options! Whatever you go for, make sure you have the necessary mechanical interfaces and if going for the off-axis guider make sure you know how to achieve the required back focus (on both cameras at the same time!) before placing your orders. I hope this help. Clear Skies!

[@AstroRef68]

Hi Great tutorial I got my asi 120 Mini I go in their website to upload drives and software but there are so many kinds I have hard time understanding what to upload yes i did load PHD2 but cant find the camera as i connected only usb i thought usb will provide power for it but looks like for power i have to use /st4 from the mount. Please give me some advise i just begin on this field

[@martinsastrophotography]

The ASI120 Mini gets its power from the USB Type C cable. You do not need to connect the st4 socket to the mount. Instead you should connect the ASI 120 only to a Windows PC, and the mount also (what mount do you have?). You may need an EQDIR cable for connection the mount. Install ASCOM Platform, then install EQASCOM and the ZWO ASI Camera driver for Windows.

[@AstroRef68]

@@martinsastrophotography Wow I didn’t know that I order st4 cable already I do have EQ-6 R from 2020 He’s I do have that cable isb to printer type I just didn’t know how to communicate to my Laptop window . Let me try what you recommend and I’ll go from there Thanks so much for your advice.

[@martinsastrophotography]

@@AstroRef68 You may be able to use a standard USB cable or you may need an EQDIR cable. Sky-Watcher updated their mounts a few years ago so it depends if your one was before or after the update. EQDIR cable plus into hand controller port. If it has a USB (Type B) port then try that first with a standard Type A to Type B USB 2.0 cable.

[@Safestassets]

Hi there, you mentioned that once it is done calibration it will automatically start guiding. At this point should I just leave it guiding if I am satisfied with the RMS error? Or should I click "Stop", then "begin looping exposures", then "auto select star", then "begin guiding" to restart guiding? I am trying to write a step by step process but I am confused what to do after calibration is done. Thanks for your help!

[@martinsastrophotography]

Hi there. Either is fine. However with the new multi star feature I usually stop it and then use ‘auto select star’ which selects multiple stars (if you have enough in your guide camera field of view) and then start guiding again by clicking the green PHD button. Hope this helps.

[@Safestassets]

@@martinsastrophotography Thanks for the quick reply. It did help!

[@zippis333]

Thank you for the Autoguiding guide - I miss one piece of information here - how should I connect HEQ5 mount to the computer? I can connect it with USB cable from SynScan hand controller (newer version hand controller with direct USB slot). Should I set the hand controller to Direct Control mode? But how in that case I can let it track the star/object at the same time? Thank you and appologize for confused question.

[@martinsastrophotography]

Hi Jan. Make sure you have installed ASCOM Platform 6.5 or later, and then install EQASCOM (which gives you EQMOD). With the new direct USB socket on the hand controller I believe you do not need to set it to PC Direct mode. Connect PHD2 via the ‘EQMOD ASCOM HEQ5/6’ mount option. You can then control the mount from the EQMOD dialog such as setting the tracking to sidereal and PHD2 can send the correction pulses to it when guiding.

[@zippis333]

@@martinsastrophotography Hi, Martin, thank you for your answer. I will try that. I have EQMOD and ASCOM Platform installed. But when I tried to connect to the mount (for example in Stellarium) it worked only in case the hand controller was in the Direct Control mode. Otherwise it told me that the mount was not connected :( But in Direct Control mode I was able to control the mount from within the Stellarium as you showed in another video (thank you for that one too :)) I will give it another try may be there was a problem on my side. And definitely I will try PHD2 autoguiding to improve from basic HEQ5 tracking. BR.

[@martinsastrophotography]

@@zippis333 I could be wrong about the direct control mode. On my HEQ5 I use an EQDIR cable in place of the handset, which does not involve PC Direct mode at all. On my EQ8-R I use a standard USB cable into the mount and have the handset connected at the same time, and PC Direct mode is not required there either. Experiment a little and you should be able to determine what works.

[@astrogerard2022]

Hi Martin. I've read that you should choose a star on the celestial meridian for calibrating. Is this true and if so does the altitude matter as well?

[@martinsastrophotography]

Hi there. The PHD2 guys recommend (in the OHD2 user manual) calibrating on a star that lies within about +/- 20 degrees of the celestial equator and which is high enough in the sky to avoid major seeing (turbulence) problems. This is very different to what you have read. There are conflicting opinions out there so I would stick with what the PHD2 guys say. Clear Skies.

[@astrogerard2022]

@@martinsastrophotography Thanks Martin

[@darkwood777]

My setup loses the guide camera image about once every 45 seconds. You can see it simply disappear, then return about 10 seconds later. This messes up guiding and I can't record a decent PEC. The camera works fine outside of PHD2. I upgraded PHD2 to the latest multistar version, but that didn't help. The mount tracks fairly well without PHD2, but I want to get this thing to work as intended.

[@martinsastrophotography]

How strange. I have never seen this problem. I suggest you email the support team of PHD2 and the support team for the camera. Hopefully they will help solve this one.

[@bordersphotography-astroco2825]

Another great video Martin. This is my next step. Can I connect the guiding camera using the same USB cable as the main camera , using a 4 port hub? Or is it better to use another 5m cable to my laptop? I have enough USB ports on my laptop for another long cable. Thanks John.

[@martinsastrophotography]

Thanks John. You can do either. Some dedicated Astrophotography cameras have a built in USB hub for this purpose. So long as the computer running PHD2 can connect to the mount and the guide camera via USB, you are in business.

[@bordersphotography-astroco2825]

@@martinsastrophotography Thanks Martin, much appreciated. I'll go long cable and ZWO 120mm mini. BR John.

[@bordersphotography-astroco2825]

All sorted now Martin, very impressed with that. I has a "backlash clearing failed " error, but once I fixed that the calibration worked fine. I did 3,5,10 and 15 minute exposures, all very good. Thanks again for your videos for getting all this set up. Hard to overstate how useful they are. BR John.

[@martinsastrophotography]

@@bordersphotography-astroco2825 Well done John. It takes some battling but it’s a great feeling when it’s cracked! Thanks for taking the time to update me on your progress. Clear Skies!

[@deeber35]

I have the Sky Watcher AZ-GTi mount in EQ mode. Can it track with a 400mm lens on a crop sensor without auto-guiding? I've had success at 300mm.

[@martinsastrophotography]

It depends on your exposure time. Longer exposure times are more likely to need autoguiding. I would suggest you set up autoguiding so you can try both with and without.

[@deeber35]

@@martinsastrophotography I don't have the gear yet, which is why I am asking so I know what can be done. Looking for 30-60 second exposures.

[@martinsastrophotography]

@@deeber35 You might be OK. It’s all a journey, so try without and see how far you can push the exposure time before the results get worse. It’s impossible to say for any given mount how good it will be because the manufacturing tolerances vary considerably from one mount to another. You can get lucky and get one that tracks really well, unlucky and get one that doesn’t…or anywhere in between!

[@Ewumm]

Hey Martin! Really awesome video, it's very helpful! However, I'm having a small issue (I know this is an old video but if you could respond, that would be great). I'm using a Celestron AVX and with a ZWO ASI120MM Mini guide camera. The ST-4 cable is connected from the camera to the Auto Guide port on the mount, but when I open EQMOD, it says "Connect Error: Port Not Available." I'm doing my best to figure it out myself online but it's not proving too effective yet. I hope you can help! Thanks.

[@martinsastrophotography]

Never connect a guide camera to an ST-4 port!!! Always connect it to your PC instead. Let me know if that solves it for you.

[@Ewumm]

@@martinsastrophotography I believe I have everything sorted now... turns out that the autoguider is connected to both the Auto Guide port on the AVX and to the laptop. I can't connect the ST-4 to the laptop because it doesn't have the port I need which was very frustrating. I figured that I could instead install CPWI to create a connection from the mount to the laptop that PHD2 will recognize, so hopefully it will work? I'm going to have clouds for at least the next week, so it's going to be a long wait.. Thanks for your help!! You've earned a sub. :)

[@martinsastrophotography]

@@Ewumm Thank you for the sub! I am not sure that what you have done will work. You should not use ST4 ports. You need to have one connection from PC to mount, one connection from PC to guide camera, and one connection from PC to imaging camera. There should be no direct connection between guide camera and mount.

[@Ewumm]

@@martinsastrophotography Perhaps the cord running from the autoguide camera to the Auto Guide port is completely unnecessary? The laptop is able to control the mount with CPWI through the serial programming port on the hand controller, so maybe that's how PHD2 is communicating with the mount as well. I'll have to set it up again tomorrow to see if that might be it. That might make sense because the selected mount connection in PHD2 is CPWI rather than EQMOD. What do you think? Still feels wrong to have nothing in the Auto Guide port, but we'll see.... in at least a week :/ This Canadian weather!

[@martinsastrophotography]

@@Ewumm You need to choose between CPWI and EQMOD. I have always used EQMOD….Works with Stellarium, NINA and PHD2, giving you all the control you will ever need, (unless you switch to a ZWO mount which has its own version of EQMOD called ‘ASI mount’). I have never used CPWI so cannot assist you with that, but I am happy to assist if you go in the EQMOD direction.

[@bigdog1452]

Why when i try to calibrate the star just goes west for like 10 mins?

[@martinsastrophotography]

You need to set up the step size. There is a calculator under the Brain button somewhere. Make sure you have the correct focal length and sensor pixel size in there as well.

[@roymixon]

Hello Martin, I am a newbie here with questions. First time using NINA and PHD2 for auto guiding, I have a question - to help me understand this correctly and complete the Focal length of Guide scope equation. I have a svbony guide scope of 206mm, and Svbony mini guide camera 3.75, main imaging camera 3.75/ASI533mc pro, my main telescope is 420mm with a field flattener reducer of 0.8x. if i did this correctly, I figured my guide scope would be - 126mm ?

[@martinsastrophotography]

Hi Roy. Some confusion is apparent in your question. You tell me the guide scope focal length is 206mm, but then at the end you ask me if it is 126mm. The important thing to check is that the image scale of your guidescope/guide camera setup is suitable for guiding your main scope/camera. With 336mm imaging focal length and 206mm guidescope focal length, and the same size pixels on both cameras, you have a very suitable setup. If you go into my website www.martinsastrophotography.com you will find a tool that enables you to calculate the minimum required guidescope focal length for your setup. Here’s a link to the calculator: martinsastrophotography.com/calculator-tools/

[@roymixon]

@@martinsastrophotography I was simply using the formula in your presentation. can I can email your with our converstation going forward? I have issues with my guiding.

[@roymixon]

never mind, I went to your website for the calculator - good stuff!

[@martinsastrophotography]

@@roymixon Glad it helped. You could guide a significantly longer focal length imaging scope with that guider setup, because the guiding can detect a fraction of a pixel movement of a guide star on the guide camera image.

[@arthurkaye8999]

Hi Martin , excellent tutorial, very informative and simply. Had no problem downloading and setting up, but when I got to the looping and calibration had some issues. Was calibrating west step only and after 2 minutes " RA Calibration failed, star did not move enough " appeared along the top of my screen. Tried to run wizard again but same problem, do you have any suggestions as to what is causing the problem? Thanks much.

[@martinsastrophotography]

Was your RA clutch open? Both clutches must be closed. Another possibility is backlash. Check that there is no wobble/rocking in RA when the clutch is closed. Also, have you built a dark library? That is important to stop it using a hot pixel instead of a star…hot pixels never move!

[@arthurkaye8999]

@@martinsastrophotography Are the RA clutches on the mount?

[@martinsastrophotography]

@@arthurkaye8999 Yes. What mount do you have?

[@arthurkaye8999]

@@martinsastrophotography my mount is a HEQ5 PRO

[@arthurkaye8999]

There is a tiny bit of back lash in the mount could this be causing the problem?

[@davorfliker2362]

Dear Martin, So far I have done everything (as i beginer) from your videos. They re very simple and easy to follow and incorporate, But now I need a help. Issue is guding with PHD2. I have PHD2 guiding 2.6.10 on windows 10. My guiding train is sky watcher HEQ5 PRO, guide scope Omegon 50 mm (focal length is 200 mm). it has coarse and fine focuser. A guide camera I am using is ZWO ASI 120 MC-S (3,7 px size) - (By the way that is my planetary camera with MAC 180) I have all EQMOD drivers and Camera drivers installed what I did with your previous windows on Stellariom installation. So two nights in a raw I tried to get guiiding (must say sky is cristal clear). Made a dark library. I have oppened two windows (graph and star profile). I focused and I have done both star choosing ; manual and auto select. Each time after looping and star selection it started calibration. An each time is the same. It starts calibration with all the wordings (East, West backlash etc, etc) But on a main screen as well on star profile star is not "playing and adjusting" around cross hair center but slowly it goes away. And than I got signal "star lost". Sometimes it started guiding but for a short period it alarms lost star , waek signal etc. Even if it starts guiding it states that t used small number of data so it is unstable. I put my ear on mount and I hear gears running and zuming. Sometimes I have rcvd msg to check cable tightness or connection or that something is wrong with mount. From what I have check they are OK. When it managed to guide I do not get any lines ocilationg arond central line as should, but only high peaks going up to 3''. And as I said when stars go away guiding stops. Only thing I did not put and that is maybe reason is that I did not enter any mount speed. To be honest I do not know where to find it among EQMOD data and where to input that info in PHD2, althoug I am not sure that is a problem. Can you help me pls Clear sky Davor

[@martinsastrophotography]

Hi Davor. Thanks for the message. I feel your pain!! The first thing to check is that you do not have excessive backlash in your mount. To check this, run the star-cross test in PHD2. You need to take a long exposure photo with your main camera while this runs. Follow the instructions. If you have minimal backlash each star will look like a ‘+’. Also, there is an option during mount connection in PHD2 to automatically read the guide speed from the mount. If you cannot find this, go to the EQMOD window after connecting to the mount and click on the spanner >>> button. The guide speed of the mount is set by the RA Rate and Dec rate sliders under ‘ASCOM PulseGuide settings’. I suggest you start with 0.4 or 0.5. There is no point trying to guide until your calibration is working properly. If you have bad backlash I have done a tutorial video on how to fix that. Let me know how you get on.

[@davorfliker2362]

@@martinsastrophotography Hi Martin. I had last night clear sky and no moon. So I tried to make cross test. First I made a cross test with PHD2. I did it 2 ways. Once as instructed 112 sec test with my camera exposure 224, and another one with half camera exposure 112 sec. The result was almost the same. I did not get any cross "+" (sorry I can not add photo to you tube). Not a sharp cross (as if I had no any backlash) nor deformed cross as would be with backlash. What I got were just stras "extended in line" as if I did it with no moving camera with long exposure. Than I made a rock test but I really did not notice any bump or movement. Than I oppened plate with RA and DEC drive. I do not have a belt drive but a one worm drive and two gears. I have checked them and DEC was fine no loose movements, and just a small "loose area" in RA on central gear. I have unscrewed plates and adjusted. I close the drive. Did not do any adjustment with alen key of the grub screws as I did not have any movement in rock test, and I do not know should I do that if I do not have a belt drive. After all was done I have repeated cross-test and got exactly the same. Like mount is not moving at all and I got only stars extended picture due to the long expoure. I put my ear on drive and heard some very low sound as it is moving.So I do not know how to proceed further. This evening I plan to make some planetary photo with Mak 180 and Syn Scan but I am afraid it will not work too if something is wrong with mount. I would appreciate if you would have some additional suggestions Clear sky Davor

[@rpg350]

Hey, I'm new to astrophotography, I've done 400 frames (20 seconds each), after registering them in DSS, only 1 frame is good to stack and only 1 star is found within the 3% range. I have mid range telescope, (432 FL & 72 Aperture) and also Colour Camera Altair Hypercam 183C PRO, do you know what im doing wrong? Please Help. (I'm using APT Tools)

[@martinsastrophotography]

Have you tried adjusting the star detection threshold in DeepSkyStacker? After clicking Register Checked Pictures go to the ‘Advanced’ tab and lower the threshold, then click the button below the slider. Keep adjusting the threshold until it detects between 100 and 200 stars ideally, but if you can’t get that many get as many as you can. Hope this helps.

[@rpg350]

@@martinsastrophotography unfortunately I did minimise to 3% and found only 1 star I don't know what am doing wrong, I hope is no camera 😕

[@martinsastrophotography]

@@rpg350 have you set the camera gain? There is an optimum gain for that camera. I think it is around 400 but check online to confirm.

[@rpg350]

@@martinsastrophotography yes thank you its actually 398 exactly I did it with SharpCap, but from all the answers I received its most likely my focus

[@martinsastrophotography]

@@rpg350Ah Ok. Get yourself a Bahtinov mask. You won’t regret it!

[@orionnebula3487]

So for me with a Nikon Z5 (6 μm) as imaging camera with a 250mm telescope and an asi 120mm guiding camera (3.75 μm) I would need a 15mm guidescope? Does that even make sense? And I just bought a 240mm guiding scope haha. Well lets see how the first light will be^^

[@martinsastrophotography]

Your guidescope has a rather long focal length for that setup, but that just means the guide star will move more pixels per arc second of tracking error. The only down side is there will be fewer stars in the guide camera’s field of view to use for guiding.

[@orionnebula3487]

@@martinsastrophotography Thank you for the quick response Martin. Glad to hear that. I am looking foreward to the next clear sky^^

[@deeber35]

I'm trying to only polar align w/ a computer connected only to the camera. I slew manually. When I try Drift Align, it says connect mount and camera. I have no mount to connect to. But, when I try Polar Align, it seems it may be working. I'm indoors, so not sure, as i can't pick a star. Any idea the difference between drift and polar align? And if my camera is taking photos, does it seem like Polar Align may work?

[@martinsastrophotography]

Astrophotography indoors! That’s a first. You really need to be outside where you can see Polaris in the northern sky. (I assume you are in the northern hemisphere?) Polaris is very useful for polar alignment since it is close to the north celestial pole. Drift alignment is a technique for polar alignment when you cannot see Polaris, but it is really for people with Goto mounts, and it still relies on you being able to see stars. If you are tracking manually, you will not be able to take long exposures due to the wobble and tracking rate error that will occur. Unless you use short exposures on a fixed tripod and stack many images, a tracking mount is an essential piece of kit for Astrophotography….

[@deeber35]

@@martinsastrophotography umm...yes, I know I have to be outside to find star. ;) It was daylight when I was installing PHD2. I can never see Polaris tho. Anyway, I have a tracker (SGP). Do I need a connected mount for Drift Align but not Polar Align? Not why 1 Polar seems to work, Drift not.

[@martinsastrophotography]

@@deeber35 Please clarify what mount you have. SGP is a software package. There are many drift alignment tutorials available on KZbin.

[@deeber35]

@@martinsastrophotography I have a non-electronic (manual mount, not connected), then the SkyGuider Pro (not connected), then mount and camera.Not sure what u mean SG Pro is software. Anyway, not sure why Polar alignment seems to work, while Drift does not, perhaps requiring a mount it can connect to, but Polar does not? I can't see Polaris here in the north heisphere, so Polar can't work"?

[@martinsastrophotography]

@@deeber35 SG Pro = Sequence Generator Pro (for me at least!) I see you use it to mean SkyGuider Pro. That’s fine. If you mount does not track, there is little use in Polar aligning it, other that to enable you to follow the movement by moving the Right Ascension axis only. Doing this manually is very crude and not suitable for deep sky Astrophotography.

[@hmarlutvunga]

i am a noob, still did not understand one thing...calibration and deift alignment without polaris...when i try to drfit align, phd2 tells me to calibrate.. when i try to calibrate, it tells me polaralignment is not good.. actually i need to polar align without polaris visible...what may be the solution please

[@martinsastrophotography]

Drift alignment is a method of polar alignment that is useful when you cannot see Polaris (in the northern hemisphere). PHD2 calibration is nothing to do with polar alignment. You need to polar align first. Then start PHD2. Once connected to the guide camera and mount you start looping and select a star, then do shift+guide button to calibrate ... a process that PHD2 needs to perform in order to know which way to command your mount to move when the guide star drifts in a given direction. A good way to think about it is to consider a perfectly polar aligned mount, but then rotating your guide camera...PHD2 will then not know any more which way to move the mount to bring the guide star back to the desired position so you would have to do a PHD2 calibration again so it can ‘learn’ which mount movements move the star in which directions. I hope this helps.

[@hmarlutvunga]

@@martinsastrophotography thanks for your reply , mean calibration can be done without polar alignment?...sorry for my curiosity

[@hmarlutvunga]

@@martinsastrophotography thanks...looking forward for your new videos👍👍👍

[@martinsastrophotography]

@@hmarlutvunga No. you must polar align before you calibrate PHD2. PHD2 is not a substitute for polar alignment. It relies on your polar alignment being reasonably good and then PHD2 improves your tracking further by correcting small errors in your tracking. If you are not polar aligned, your errors will be very large and PHD2 will probably not cope.

[@Stefaon]

Je cherche une vidéo en français. Je trouve une vidéo avec un titre et un résumé en français, je clique sur la vidéo : elle est en anglais.

[@martinsastrophotography]

Excuses-moi! Je ne sais pas pourquoi ca a fait ca. Ciels Clair!!

[@vcotta2012]

Phd2 isn't reading my guide camera or mount! What's going on?

[@martinsastrophotography]

Have you installed ASCOM Platform and also the ASCOM drivers for your camera and mount? What camera and mount do you have? Are you using a windows PC? How have you connected your camera and mount to the computer?

[@vcotta2012]

@Martin’s Astrophotography I have not. I have a ZWO ASI 120mm guiding scope camera and Ioptron Skyguider Pro.

[@vcotta2012]

@@martinsastrophotography yes, I'm using Windows PC. I'm hooking the mount and camera to the USB ports.

[@martinsastrophotography]

@@vcotta2012 Personally I never bother guiding with my iOptron Skyguider pro. You can only guide in RA, and to be honest if you do your polar alignment properly you can comfortably do 60 second exposures without guiding. Anyway, if you want to give it a try you will need to install ASCOM Platform and then the drivers for the camera and mount.

[@vcotta2012]

@Martin’s Astrophotography I'm new to this hobby, what's RA? Also, where do I receive the proper drivers and ASCOM platform?