These videos that you are making with Glenn are wonderful. I will delve deeper into my PEC function with the Celestron mounts (CGEM & CGX) and their CPWI software.
Thanks Pat. I'm glad it's bringing more awareness about PEC to the community and hope it is helping those who either don't know about it or want more information. I think every little bit helps us all take better photos.
I have just spent three days trying to turn on PERMANENT Periodic Error Correction on my Sky-Watcher HEQ5 mount to no avail. I won’t bore you with the details but in the end I turned to my Sky-Watcher instruction manual for clarity on mount compatibility, here’s what I found out. The hand book for Sky-Watcher mounts states that there are two types of PEC depending on the mount model. Sky watcher mount models EQ3 / EQ5 / HEQ5 / EQ6 pro are software based and use Periodic Error Correction - PEC. (The mount hand set needs to be connected to utilise the PEC function and will not work or be turned on if it is disconnected.) The only Sky watcher mounts capable of using PERMANENT Periodic Error Correction - PPEC are models: AZ-EQ6GT and EQ8. Hope this help shed a little light on PERMANENT Periodic Error Correction mount compatibility.
Hi Joe and Glen, Great timing for me. Thankyou so much. I'm about to do the Rowen Belt mod on my HEQ5 pro, so fine tuning PEC and PHD2 will be just great for my data sets. Thanks again Legends!
I really wanted to know about this but I was afraid to do anything not to screw up my mount, so thanks for the collaboration . I have the same mount and my guiding has been so-so, not terrible but the average error correction in PHD2 was hovering around .85-1.15 with sometimes large swings on the RA axis. I tried all sorts of ways to reduce it, like kept re-balancing and also made physical adjustments on the mount itself with the worm screws to remove backlash, but it didn't significantly improve much. I'm gonna try this next once I get a clear sky (when will we be rid of these snowstorms??) and maybe spend a few hours tinkering with this. Thanks!
Thanks for watching and commenting Frank! I hope it helps you. Are you also using the new dev version of PHD2 with multi star guiding? That made a big difference for me as well in my total RMS error.
Jorge Gálvez Castilla (Sorry man, UA-cam ate your comment, but I do see it in my alerts and copy/pasted for you) I cannot do the recording process successfully. I select record pec and the process starts. The light starts to flash and then changes to 2 flashes which indicates that it starts recording, but after about 8-10 minutes the light stops flashing and nothing happens. It does not change to 3 lights flashing and not indicate in any way that the recording has finished, so I end up unchecking the recording option and I mark the check to activate PEC to see if it works, but neither. I don't know if I have to wait longer until he tells me that the recording has finished or something. This point is not clear from the video. How do I know the recording is over? Does EQMOD give any message? Thanks and excuse for my english
The recording can take up to 20 minutes to finish. If you click on Record PPEC and then click the "Refresh" button it should say recording. Wait about 10 minutes and click "Refresh" and then again at 20 minutes. It will let you know that it is no longer recording and then you should be able to check the box "Enable PPEC" and then click "Refresh". Let me know if it works for you. Also remember to save your PEC recording in EQMOD. I've had power outages and have had to reset my mount and lost the PPEC before. You could just load it back and re-record back to the mount again. Hope that helps!
very informative thanks, i just dont get one thing.. how does eqmod check the error, what is its feedback to know the error of the worm gear? I have only ever done PEC training on a synscan hand controller of the eq5 mount and the feedback was my eye, keeping the star centred for the duration of the pec trainning. There are no encoders on the eq5 so is this a requirement to use Eqmod PEC?
Thanks Jon, I'm not the guru on PEC as much as Glenn is obviously, but it's my understanding from reading info on it and working with Glenn that PHD2 guiding is turned on while PEC training. I believe that it's reading or predicting the correction error from PHD2 and creating a curve of that motion. The more worm periods it goes through, the better the prediction becomes (kind of like stacking multiple subs). Once you have this data (the PEC curve), you can then save it and reuse it each time you image with EQMOD. Additionally, if your mount supports it, you can write it to the memory in the mount to save permanently. I don't own an EQ5, but I was under the impression it had this capability, but I'm not positive.
@@JoesAstrophoto I'm a bit in the same situation as jonnic2000 but I've got something to say : if recording PEC while PHD2 is guiding gives a better tracking afterwards, one could conclude that recording a PEC is needless as long as you have PHD2 to guide ! Does that make sense ? In other words, recording a PEC is mostly needed if, afterwards, you don't use PHD2 (the mount knows how to behave by itself, without the need of PHD2)...
@@gloubiboulgazeblob Hi G, the PEC curve is trying to counteract the physical imperfections or the normal harmonic periodic error of the RA worm gear. The reason you record this in EQMOD while guiding is to help EQMOD distinguish that error. You could also use PemPro (paid software) to guide on a star without the aid of PHD2 to establish this same harmonic error. Once the mount has the PEC training it is now tracking that much cleaner during normal operations. You still want to guide of course unless you have a mount with absolute encoders. If you don't want to take the trouble to train a PEC curve or you are already guiding with a total RMS error under your image scale, then using the PPEC algorithm in PHD2 is very similar as after two worm cycles it starts to predict that same RA periodic worm error. I use a PEC curve when using my EQ6 with the hysteresis algorithm in PHD2 and I get better results than no PEC curve with PPEC algorithm. I just use the PPEC algorithm in PHD2 when using my CEM120 as it rarely guides above .5 total RMS error and my image scale is .66"/pixel. Hope that helps.
Thanks for watching and commenting Rafael. It’s my understanding that the Pec algorithm in PHD2 is doing the same thing that the autopec in EQMOD is doing. I don’t think however that you can save the pec curve to your mount with PHD2. I use the hysteresis algorithm, but definitely try it out. I know with PHD2 though, you need to get a curve every time you switch targets and I’m too lazy for that.
I have a AZ-EQ6 and did record PEC manually (no PHD2 at that time). AZ-EQ6 provides a PPEC (Permanent PEC) by default. 1°) Now, I would do it while PHD2 is running to have a better PPEC recording (the better the training the better the PEC, right ?) In your steps in the description, you don't mentionn to record PEC while PHD2 is guiding, which surprises me a bit, or maybe it was obvious to all... I did a recording while PHD2 was running and it finished the whole process successfuly but I forgot the 2 other parameters (on the left in the second panel of EQMOD), one that should be set to "1" and the other to "9" (number of cycles if I'm not mistaken). Do I have to start the whole process over again ? 2°) As I understand now, we can, or even better, we should use sidereal + PEC tracking while PHD2 is running, right ?
Thanks G! You are correct, you record PEC in EQMOD while guiding in PHD2. You will want to redo it with gain 1. The more cycles you do the better so I put that to 9, but 5 or more should be ok. EQMOD will average out the curves of each one for you. This helps in case of wind gust, bad seeing, clouds, etc. while recording a single worm cycle. After finished, you will want to run sidereal + pec while guiding in PHD2. I normally run the hysteresis algorithm on mounts with pec running and the PPEC algorithm in PHD2 on mounts without pec running. Feel free to experiment with that.
Where i am interested in this, as a ZWO ASIair user, do you think you could train say, an NEQ6 mount (thats my setup) and have it such that when the file is uploaded from it to the mount, that might be used when using the ASIAir? While the ASIair does calibrate, there is no PEC training in it and no plan to do so. Probably because its not supported by the platform it uses (NINA, i think). What i might do is experiement and see if it does work. I know ZWO have said they have no plans to add it. That could be a problem for them moving forward i think.
Hi Alastair, I've never used the ASIAIR before so I couldn't say for sure, but it sounds like it would work. Once the PEC is recorded in the mount, the light on the mount should blink 3 times quickly continuously. You could easily test it out and if the red light is blinking, then you know it's working even though you wouldn't be able to see it in the ASIAIR interface.
Wow Joe !!.. that was an amazing and easy explanation of the PEC,, What I am in lost with is : What setting do I need to put into PHD2 to accept that PEC (if there is any) and what setting in the mount should be applied except PEC recordings.. My mount is Atlas eq-g and got Tot of 0.9-0.8 but I am eager to get better than that. Thanks
Thanks for watching and commenting! It’s my understanding that the Atlas is basically the same as the EQ6 and if that’s truly the case then you don’t have to really tell Phd2 or the mount anything. Eqmod should take care of everything.
Hey Joe, awesome explanation of thi somewhat foggy subject! I'm curious how you got the "development area" to show up? Or is this feature only avaiable for the EQ6-R and not the HEQ5? Many thanks!
Thanks Fixarn! As far as I know, the HEQ5 doesn't have a PPEC feature, but you can save the PEC curve you trained in EQMOD and just reload it anytime you want to and just run it there. As a matter of fact, I've been doing this lately as I've been experimenting with different PEC curves. As long as you park the mount before turning it off, EQMOD will retain the PEC curve and even if you forget or lose it somehow, you can just click on the folder in the PEC area and load it back in. Hope that helps.
Hi Joe. Great video, you guys obviously work well together. I have a couple of questions though. First how long does a PPEC last? Unfortunately I am unable to leave my EQ6 rig setup and so it gets moved a lot. Does moving the mount affect the PPEC? Also should the PEC be recorded carrying a normal setup or empty? Does having a vastly different set up on the mount change the PPEC?
Thanks Richard, the PPEC actually is a measurement and correction of the periodic error in the RA worm gear, so yes you’ll want to record it while the mount is setup and you are guiding. Once recorded you are done, it will last for years as long as you don’t adjust anything related to the way the RA worm gears mesh together. You can absolutely move the mount and change setups, this shouldn’t effect anything. The only caution is to make sure the mount does not slew while recording the PEC including doing a meridian flip. If you watch my video about rebuilding and tuning the EQ6, you’ll be able to better picture the periodic error in the worm gear in your head. Hope this helps!
First of all, thanks to you and Glenn for a great video tutorial. I am now a subscriber to both you and Glenn and I am looking forward to learning a lot from both of you. I am exactly where you were, Joe, with my guiding except I am also trying to guide a 8" SCT on a EQ6-R Pro which, as you might imagine, I am finding challenging. I do have a couple of follow-on questions if you don't mind. 1. Once I complete the PPEC recording and transfer to the mount motor control boards, should the mount light always blink 3 times when PPEC is Enabled or is this a temporary condition of the initial transfer? 2. In a comment from another person below, I saw where he mentioned turning dither OFF when doing the PEC recording but I noticed you had dithering ON and set at every 2 images in the video. Which is recommended; ON or OFF? 3. Glenn mentioned in the video that when his guiding is sometimes not as good as it should be, he does a PHD2 cal. Should a PHD2 cal be done before the start of PEC recording to maximize guiding precision or does it really matter? 4. Lastly, can you erase a PPEC that has been transferred to the motor control boards or write a new PPEC to the motor control boards? If I don't like the results of a PPEC, can I erase it, return to whatever default is there now without the update or run another recording/recordings and load a new curve to the motors? I would really like to understand if what I do with the PPEC transfer to the motor control boards is reversible or updateable. Thank you both again for a great instructional video. I am anxious to try this out. I am finally getting clear skies and electricity for the first time in days (yes I live in Texas) and tomorrow night looks like it might be an opportunity. Take care, be safe and both of you, please keep the videos coming.
Many thanks Christopher! I asked Glenn to help answer as he’s the real pro for pec. I know you can remove or change the pec curve after you add it so no worries about that. I’ve heard people say to turn dither off but Glenn says it doesn’t hurt and worked just fine for me. I’ll let him chime in as well.
Hi Christopher, 1 Whenever PPEC is enabled and running the light will blink to show this. 2 Dithering can be left on. I am only aware that slewing and or meridian flips are to be avoided while recording 3 I do a calibration before I record. The PEC are the errors that are in your worm drive so even after this is completed further calibrations if you feel guiding is not good are not something you shouldn't consider. You still have the DEC axis to control via guiding as PEC only controls the RA 4 If you record a new curve that will replace one that is there. If you want to start over then via the handset I would do a factory reset. Hope this helps
@@JoesAstrophoto Thank you both so very much. I plan to give this a try tonight if all holds as expected. You both have a dedicated subscriber from now on!!! Take care, be safe and hope we can exchange electrons again soon. Thank you.
@@Astrobloke Thank you both so very much. I plan to give this a try tonight if all holds as expected. You both have a dedicated subscriber from now on!!! Take care, be safe and hope we can exchange electrons again soon. Thank you.
E-X-C-E-L-L-E-N-T!!!! I am/was in the exact same situation, looking forward testing it! I just need a clear night. At least one in the next 6 months ex-PEC-ted...
Thanks Kevin, unfortunately I do not have anything setup at the moment to go into to check for you. If you have a mount capable of recording a PEC curve, then it should show under the "Developer" section. I only have an iOptron setup at the moment and it's not compatible with EQMOD. My EQ6 is in storage at the moment. If you can't get it to record to the mount, you can still save it as a file on your computer and load it before starting each night. I think EQMOD loads it automatically actually. I'll have my EQ6 back in operation this spring, and I'll test it out with the latest EQMOD version and let you know.
My guiding is definitely worse the colder the temperatures become during the night. On nights where the temperature is below freezing the mount seems to go through sequences of sticking. I added a heating wrap to the mount and that seems to help a bit. Without opening up the mount, my guess is that the worm lubrication gets stiff at below freezing temperatures causing the stars to trail. I haven't run PEC under different temperatures since this is not really a periodic error problem, but a random one. I'm not sure what other people do on sub-freezing nights, but those are typically the clearest nights of the year.
Thanks darkwood! You are correct that it’s not periodic error. The metal in most of these mounts will contract and expand with extreme temperatures. Unfortunately what you are describing is the worm gear binding. You can correct this by adjusting the worm gear either in or out, but in my option it’s not worth the hassle unless you are very comfortable doing it on a normal basis. I adjust my EQ6 a couple times a year because where I live we get extreme weather hot and cold. My CEM 120, I’m finding out is not really viable under -10c (14f). The other thing as you said is to keep the mount warm, which I’m working on ideas for.
Hi Joe and Glen. Have watched your videos with interest. I have an eq 6r pro mount controlled by an Asiair pro unit. If I record the PPEC to the Ra motor and then use the air pro are there likely to be any problems guiding? I presume that the PEC will automatically start once the mount is guiding because the asiair will not initiate it. Thanks John Wright.
Hi John, thanks! Once you record a pec curve to the mount it should work with anything. I have never used the ASIAIR but I wouldn’t think it would cause any issues at all. You will be able to tell if pec is working as your mount should blink 3 times in a row if it is guiding + pec. Good luck!
Thanks for coming back Joe. One final question if I may. If the PPEC causes problems is it possible to revert the motor to its original state prior to the PEC Training? Thanks JW.
Great video. Reallly good demonstration of this feature. Unfortunately I can't test it out since my EQ6 is no longer with me. Still undecided what's my next mount going to be. EQ8-R maybe?
Many thanks PJ! I don’t think you can go wrong with the EQ8. I love my EQ6 and my CEM120, but iOptron’s QC has gotten so bad, it’s a gamble to get a working mount.
@@JoesAstrophoto That's why I'm struggeling. I think my old EQ6 was case of bad QC as well and I was fighting with it for years until a local repair shop guy found out, that both worm wheels were untrue and caused the gears to bind. I think the iOptron mounts are a bit overpriced concerning their poor QC.
@@pnjunction5689 I can agree with that. At this point with the price of the EQ8 and CEM70/120, it's probably a better decision to spend a couple grand more and go with the higher brands like AP, SB, or the like.
@@JoesAstrophoto Yeah, I wish I had that kind of money lying around. It would make the process a lot easier. The Losmandy G11T would also be in a similar price range, but you get mixed opinions on these, too. I guess in the end it all comes down to an extended return policy ;-)
Hi Andy, I believe you need to hook it up to your PC to PEC train through EQMOD. Once you write the PEC curve to the mount, you should, in theory be able to go back to using the ASIAIR. You know the mount is using the recorded PEC if the light on the mount is flashing 3 times in a row. This all is assuming you have a EQMOD compatible and PEC writeable mount like the EQ6, EQ8, Orion Atlas, etc.
Thanks for the comment Bill. I’ve not had any issues recording PEC with dithering on. You do want to make sure you don’t slew or do a meridian flip while recording however. Ask me how I know that one lol
Yes, one and the same. I’ll be honest, I never used it with the hand controller. I actually used the hand controller 3 times and after going batty from trying to do a 3 star alignment, I found plate solving and never really used the hand controller again, but if you do use the hand controller then it’s the same you would do with it.
@@JoesAstrophoto Just had a go tonight unfortunately this is not available on the HEQ5 Pro, I check the website it's listed against the HEQ6 but not the 5. Oh well still got guiding anyway. Good to know though. 👍
@@OlliesSpace Hey Ollie, sorry to hear, I looked it up too and it doesn’t seem like HEQ5 has the encoders to save a ppec, but you can still do the autopec in EQMOD and save the file and use it each time if you wish.
@@JoesAstrophoto Cool I'll give this autopec a try. I did also read that when you do the PEC routine you shouldn't be dithering your image which I guess makes sense, so I'll try switching this off when I do it.
Hi Andy! You would not need to redo your PEC for things like that. The PEC is only correcting the periodic error in your worm gear. As your mount gets a lot of use it may start to change that error and you'd want to record a new PEC curve to re-correct. I don't really know how long that would be, probably depends on your mount and how often it's used. I did have a weird power outage that reset my mount and I found I had to re-record my PEC curve before.
Hi, I’ve never used an ASIAIR, but you can test it out. After getting a permanent pec written to the mount, the mount’s led should blink red 3 times over and over. If after you turn the mount back on it’s not blinking that way, you should be able to enable on the hand controller and then it will be active while using the ASIAIR. If you do test it, please let me know if it works that way.
Thanks Llamar! Actually that was Glenn's mount towards the end of the video we were looking at while recording the PEC curve. I'm assuming he had his set to x0.20 because that's what the Guiding Assistant in PHD2 recommended, but I'm not positive. I have mine set to x0.50 but I have vastly different conditions where I live than where he does. I'm not an expert by any means and I don't want to tell anyone the wrong thing, but I believe you want to be a little lower than optimal on your guide rate towards zenith and then as you approach the horizon PHD2 should start sending quicker pulses. Again, I'm not exactly positive on this and if anyone know better please chime in.
Hi AK, I'm pretty sure it's not possible with the ASIAIR. I know it's possible to do it through the hand controller, but no idea how. The easiest way to do it is to hook it up to a laptop or pc long enough to record the PEC curve, then resume using your ASIAIR. Once the PEC curve is recorded to your mount, when it's on the power light will always blink 3 times in succession so you'll know it working since you won't have EQMOD to see it. I would say unless you're having some really bad RMS numbers, it's not worth the hassle.
Oh no Dennis, sorry to hear! How did the pec curve look before training? Please let me know if I can be of any help and I’ll do what I can to help troubleshoot.
@@JoesAstrophoto Thanks! I actually posted this vid to my club's facebook page but I do have a question- I heard you should near the meridian and celestial equator when you do this and you should be guiding. Is that true? If so, does the quality of your guiding setup reflect on the quality of your pec curve? It looked like he was tweaking guiding while the pec recording was going.
@@AstroDenny Thanks for sharing my video Dennis. I've heard a few things about having your dec at 0 degrees so close to the meridian however you want to make sure your mount does not do a meridian flip or slew while recording. I don't and I have a pretty smooth curve. You can mess with guiding a bit if you need to and you can dither as well in my experience. Hope that helps.
Just moving into mono (once clouds disappear) so watching a lot of helpful stuff before it starts, mostly you and Glenn to be fair. Thought I'd do my own research beforehand, as I know Glenn will get hundreds of questions otherwise haha. Keep making the vids mate, it's brilliant and so helpful
Nice video Joe. Thank you again for letting me use your gear it was a fun experience and I am really happy we were able to help improve your guiding.
Thanks Glenn, it was a lot of fun and I'm excited to try it out when I get some clear skies!
These videos that you are making with Glenn are wonderful.
I will delve deeper into my PEC function with the Celestron mounts (CGEM & CGX) and their CPWI software.
Thanks Pat. I'm glad it's bringing more awareness about PEC to the community and hope it is helping those who either don't know about it or want more information. I think every little bit helps us all take better photos.
I have just spent three days trying to turn on PERMANENT Periodic Error Correction on my Sky-Watcher HEQ5 mount to no avail. I won’t bore you with the details but in the end I turned to my Sky-Watcher instruction manual for clarity on mount compatibility, here’s what I found out.
The hand book for Sky-Watcher mounts states that there are two types of PEC depending on the mount model.
Sky watcher mount models EQ3 / EQ5 / HEQ5 / EQ6 pro are software based and use Periodic Error Correction - PEC. (The mount hand set needs to be connected to utilise the PEC function and will not work or be turned on if it is disconnected.)
The only Sky watcher mounts capable of using PERMANENT Periodic Error Correction - PPEC are models: AZ-EQ6GT and EQ8.
Hope this help shed a little light on PERMANENT Periodic Error Correction mount compatibility.
Hi Joe and Glen,
Great timing for me. Thankyou so much. I'm about to do the Rowen Belt mod on my HEQ5 pro, so fine tuning PEC and PHD2 will be just great for my data sets. Thanks again Legends!
Thanks Chris, I'm so glad this helped you, good luck, it really does help.
I really wanted to know about this but I was afraid to do anything not to screw up my mount, so thanks for the collaboration . I have the same mount and my guiding has been so-so, not terrible but the average error correction in PHD2 was hovering around .85-1.15 with sometimes large swings on the RA axis. I tried all sorts of ways to reduce it, like kept re-balancing and also made physical adjustments on the mount itself with the worm screws to remove backlash, but it didn't significantly improve much. I'm gonna try this next once I get a clear sky (when will we be rid of these snowstorms??) and maybe spend a few hours tinkering with this.
Thanks!
Thanks for watching and commenting Frank! I hope it helps you. Are you also using the new dev version of PHD2 with multi star guiding? That made a big difference for me as well in my total RMS error.
Thanks to both of you! Just completed doing this last night :) RMS is down to .50 woot!
Awesome Jason! I'm so glad it helped you out!
Jorge Gálvez Castilla (Sorry man, UA-cam ate your comment, but I do see it in my alerts and copy/pasted for you)
I cannot do the recording process successfully. I select record pec and the process starts. The light starts to flash and then changes to 2 flashes which indicates that it starts recording, but after about 8-10 minutes the light stops flashing and nothing happens. It does not change to 3 lights flashing and not indicate in any way that the recording has finished, so I end up unchecking the recording option and I mark the check to activate PEC to see if it works, but neither. I don't know if I have to wait longer until he tells me that the recording has finished or something. This point is not clear from the video. How do I know the recording is over? Does EQMOD give any message? Thanks and excuse for my english
The recording can take up to 20 minutes to finish. If you click on Record PPEC and then click the "Refresh" button it should say recording. Wait about 10 minutes and click "Refresh" and then again at 20 minutes. It will let you know that it is no longer recording and then you should be able to check the box "Enable PPEC" and then click "Refresh". Let me know if it works for you. Also remember to save your PEC recording in EQMOD. I've had power outages and have had to reset my mount and lost the PPEC before. You could just load it back and re-record back to the mount again. Hope that helps!
very informative thanks, i just dont get one thing.. how does eqmod check the error, what is its feedback to know the error of the worm gear? I have only ever done PEC training on a synscan hand controller of the eq5 mount and the feedback was my eye, keeping the star centred for the duration of the pec trainning. There are no encoders on the eq5 so is this a requirement to use Eqmod PEC?
Thanks Jon, I'm not the guru on PEC as much as Glenn is obviously, but it's my understanding from reading info on it and working with Glenn that PHD2 guiding is turned on while PEC training. I believe that it's reading or predicting the correction error from PHD2 and creating a curve of that motion. The more worm periods it goes through, the better the prediction becomes (kind of like stacking multiple subs). Once you have this data (the PEC curve), you can then save it and reuse it each time you image with EQMOD. Additionally, if your mount supports it, you can write it to the memory in the mount to save permanently. I don't own an EQ5, but I was under the impression it had this capability, but I'm not positive.
@@JoesAstrophoto I'm a bit in the same situation as jonnic2000 but I've got something to say : if recording PEC while PHD2 is guiding gives a better tracking afterwards, one could conclude that recording a PEC is needless as long as you have PHD2 to guide ! Does that make sense ? In other words, recording a PEC is mostly needed if, afterwards, you don't use PHD2 (the mount knows how to behave by itself, without the need of PHD2)...
@@gloubiboulgazeblob Hi G, the PEC curve is trying to counteract the physical imperfections or the normal harmonic periodic error of the RA worm gear. The reason you record this in EQMOD while guiding is to help EQMOD distinguish that error. You could also use PemPro (paid software) to guide on a star without the aid of PHD2 to establish this same harmonic error. Once the mount has the PEC training it is now tracking that much cleaner during normal operations. You still want to guide of course unless you have a mount with absolute encoders. If you don't want to take the trouble to train a PEC curve or you are already guiding with a total RMS error under your image scale, then using the PPEC algorithm in PHD2 is very similar as after two worm cycles it starts to predict that same RA periodic worm error. I use a PEC curve when using my EQ6 with the hysteresis algorithm in PHD2 and I get better results than no PEC curve with PPEC algorithm. I just use the PPEC algorithm in PHD2 when using my CEM120 as it rarely guides above .5 total RMS error and my image scale is .66"/pixel. Hope that helps.
Thanks for the video, I have one question after enabling PEC do you have to change the Mounting Guide Algorithms to Predictive PEC within PHD2?
Thanks for watching and commenting Rafael. It’s my understanding that the Pec algorithm in PHD2 is doing the same thing that the autopec in EQMOD is doing. I don’t think however that you can save the pec curve to your mount with PHD2. I use the hysteresis algorithm, but definitely try it out. I know with PHD2 though, you need to get a curve every time you switch targets and I’m too lazy for that.
I have a AZ-EQ6 and did record PEC manually (no PHD2 at that time). AZ-EQ6 provides a PPEC (Permanent PEC) by default.
1°) Now, I would do it while PHD2 is running to have a better PPEC recording (the better the training the better the PEC, right ?)
In your steps in the description, you don't mentionn to record PEC while PHD2 is guiding, which surprises me a bit, or maybe it was obvious to all...
I did a recording while PHD2 was running and it finished the whole process successfuly but I forgot the 2 other parameters (on the left in the second panel of EQMOD), one that should be set to "1" and the other to "9" (number of cycles if I'm not mistaken).
Do I have to start the whole process over again ?
2°) As I understand now, we can, or even better, we should use sidereal + PEC tracking while PHD2 is running, right ?
Thanks G! You are correct, you record PEC in EQMOD while guiding in PHD2. You will want to redo it with gain 1. The more cycles you do the better so I put that to 9, but 5 or more should be ok. EQMOD will average out the curves of each one for you. This helps in case of wind gust, bad seeing, clouds, etc. while recording a single worm cycle. After finished, you will want to run sidereal + pec while guiding in PHD2. I normally run the hysteresis algorithm on mounts with pec running and the PPEC algorithm in PHD2 on mounts without pec running. Feel free to experiment with that.
Heard of PEC but never looked into. Great demo...will be giving this ago next time those twinkly things make an appearance! ;)
Thanks, I hear ya on that, it's been cloudy here for weeks unfortunately.
Where i am interested in this, as a ZWO ASIair user, do you think you could train say, an NEQ6 mount (thats my setup) and have it such that when the file is uploaded from it to the mount, that might be used when using the ASIAir?
While the ASIair does calibrate, there is no PEC training in it and no plan to do so. Probably because its not supported by the platform it uses (NINA, i think).
What i might do is experiement and see if it does work. I know ZWO have said they have no plans to add it. That could be a problem for them moving forward i think.
Hi Alastair, I've never used the ASIAIR before so I couldn't say for sure, but it sounds like it would work. Once the PEC is recorded in the mount, the light on the mount should blink 3 times quickly continuously. You could easily test it out and if the red light is blinking, then you know it's working even though you wouldn't be able to see it in the ASIAIR interface.
Wow Joe !!.. that was an amazing and easy explanation of the PEC,,
What I am in lost with is : What setting do I need to put into PHD2 to accept that PEC (if there is any)
and what setting in the mount should be applied except PEC recordings..
My mount is Atlas eq-g and got Tot of 0.9-0.8 but I am eager to get better than that.
Thanks
Thanks for watching and commenting! It’s my understanding that the Atlas is basically the same as the EQ6 and if that’s truly the case then you don’t have to really tell Phd2 or the mount anything. Eqmod should take care of everything.
Hey Joe, awesome explanation of thi somewhat foggy subject! I'm curious how you got the "development area" to show up? Or is this feature only avaiable for the EQ6-R and not the HEQ5? Many thanks!
Thanks Fixarn! As far as I know, the HEQ5 doesn't have a PPEC feature, but you can save the PEC curve you trained in EQMOD and just reload it anytime you want to and just run it there. As a matter of fact, I've been doing this lately as I've been experimenting with different PEC curves. As long as you park the mount before turning it off, EQMOD will retain the PEC curve and even if you forget or lose it somehow, you can just click on the folder in the PEC area and load it back in. Hope that helps.
Hi Joe. Great video, you guys obviously work well together. I have a couple of questions though. First how long does a PPEC last? Unfortunately I am unable to leave my EQ6 rig setup and so it gets moved a lot. Does moving the mount affect the PPEC? Also should the PEC be recorded carrying a normal setup or empty? Does having a vastly different set up on the mount change the PPEC?
Thanks Richard, the PPEC actually is a measurement and correction of the periodic error in the RA worm gear, so yes you’ll want to record it while the mount is setup and you are guiding. Once recorded you are done, it will last for years as long as you don’t adjust anything related to the way the RA worm gears mesh together. You can absolutely move the mount and change setups, this shouldn’t effect anything. The only caution is to make sure the mount does not slew while recording the PEC including doing a meridian flip. If you watch my video about rebuilding and tuning the EQ6, you’ll be able to better picture the periodic error in the worm gear in your head. Hope this helps!
First of all, thanks to you and Glenn for a great video tutorial. I am now a subscriber to both you and Glenn and I am looking forward to learning a lot from both of you. I am exactly where you were, Joe, with my guiding except I am also trying to guide a 8" SCT on a EQ6-R Pro which, as you might imagine, I am finding challenging. I do have a couple of follow-on questions if you don't mind.
1. Once I complete the PPEC recording and transfer to the mount motor control boards, should the mount light always blink 3 times when PPEC is Enabled or is this a temporary condition of the initial transfer?
2. In a comment from another person below, I saw where he mentioned turning dither OFF when doing the PEC recording but I noticed you had dithering ON and set at every 2 images in the video. Which is recommended; ON or OFF?
3. Glenn mentioned in the video that when his guiding is sometimes not as good as it should be, he does a PHD2 cal. Should a PHD2 cal be done before the start of PEC recording to maximize guiding precision or does it really matter?
4. Lastly, can you erase a PPEC that has been transferred to the motor control boards or write a new PPEC to the motor control boards? If I don't like the results of a PPEC, can I erase it, return to whatever default is there now without the update or run another recording/recordings and load a new curve to the motors? I would really like to understand if what I do with the PPEC transfer to the motor control boards is reversible or updateable.
Thank you both again for a great instructional video. I am anxious to try this out. I am finally getting clear skies and electricity for the first time in days (yes I live in Texas) and tomorrow night looks like it might be an opportunity. Take care, be safe and both of you, please keep the videos coming.
Many thanks Christopher! I asked Glenn to help answer as he’s the real pro for pec. I know you can remove or change the pec curve after you add it so no worries about that. I’ve heard people say to turn dither off but Glenn says it doesn’t hurt and worked just fine for me. I’ll let him chime in as well.
Hi Christopher,
1 Whenever PPEC is enabled and running the light will blink to show this.
2 Dithering can be left on. I am only aware that slewing and or meridian flips are to be avoided while recording
3 I do a calibration before I record. The PEC are the errors that are in your worm drive so even after this is completed further calibrations if you feel guiding is not good are not something you shouldn't consider. You still have the DEC axis to control via guiding as PEC only controls the RA
4 If you record a new curve that will replace one that is there. If you want to start over then via the handset I would do a factory reset.
Hope this helps
@@Astrobloke Thanks Glenn, great information as always!
@@JoesAstrophoto Thank you both so very much. I plan to give this a try tonight if all holds as expected. You both have a dedicated subscriber from now on!!! Take care, be safe and hope we can exchange electrons again soon. Thank you.
@@Astrobloke Thank you both so very much. I plan to give this a try tonight if all holds as expected. You both have a dedicated subscriber from now on!!! Take care, be safe and hope we can exchange electrons again soon. Thank you.
E-X-C-E-L-L-E-N-T!!!! I am/was in the exact same situation, looking forward testing it! I just need a clear night. At least one in the next 6 months ex-PEC-ted...
Thanks Jean, I'm glad you liked it and I really hope it helps you out! Good luck!
Great video I do not have the record faculty on my software do I need to down load a different version
Thanks Kevin, unfortunately I do not have anything setup at the moment to go into to check for you. If you have a mount capable of recording a PEC curve, then it should show under the "Developer" section. I only have an iOptron setup at the moment and it's not compatible with EQMOD. My EQ6 is in storage at the moment. If you can't get it to record to the mount, you can still save it as a file on your computer and load it before starting each night. I think EQMOD loads it automatically actually. I'll have my EQ6 back in operation this spring, and I'll test it out with the latest EQMOD version and let you know.
My guiding is definitely worse the colder the temperatures become during the night. On nights where the temperature is below freezing the mount seems to go through sequences of sticking. I added a heating wrap to the mount and that seems to help a bit. Without opening up the mount, my guess is that the worm lubrication gets stiff at below freezing temperatures causing the stars to trail. I haven't run PEC under different temperatures since this is not really a periodic error problem, but a random one. I'm not sure what other people do on sub-freezing nights, but those are typically the clearest nights of the year.
Thanks darkwood! You are correct that it’s not periodic error. The metal in most of these mounts will contract and expand with extreme temperatures. Unfortunately what you are describing is the worm gear binding. You can correct this by adjusting the worm gear either in or out, but in my option it’s not worth the hassle unless you are very comfortable doing it on a normal basis. I adjust my EQ6 a couple times a year because where I live we get extreme weather hot and cold. My CEM 120, I’m finding out is not really viable under -10c (14f). The other thing as you said is to keep the mount warm, which I’m working on ideas for.
Hi Joe and Glen. Have watched your videos with interest. I have an eq 6r pro mount controlled by an Asiair pro unit. If I record the PPEC to the Ra motor and then use the air pro are there likely to be any problems guiding? I presume that the PEC will automatically start once the mount is guiding because the asiair will not initiate it. Thanks John Wright.
Hi John, thanks! Once you record a pec curve to the mount it should work with anything. I have never used the ASIAIR but I wouldn’t think it would cause any issues at all. You will be able to tell if pec is working as your mount should blink 3 times in a row if it is guiding + pec. Good luck!
Thanks for coming back Joe. One final question if I may. If the PPEC causes problems is it possible to revert the motor to its original state prior to the PEC Training? Thanks JW.
@@johnwright6410 No problem John and yes, you can reset the mount with the hand controller very easily.
Great video. Reallly good demonstration of this feature. Unfortunately I can't test it out since my EQ6 is no longer with me. Still undecided what's my next mount going to be. EQ8-R maybe?
Many thanks PJ! I don’t think you can go wrong with the EQ8. I love my EQ6 and my CEM120, but iOptron’s QC has gotten so bad, it’s a gamble to get a working mount.
@@JoesAstrophoto That's why I'm struggeling. I think my old EQ6 was case of bad QC as well and I was fighting with it for years until a local repair shop guy found out, that both worm wheels were untrue and caused the gears to bind. I think the iOptron mounts are a bit overpriced concerning their poor QC.
@@pnjunction5689 I can agree with that. At this point with the price of the EQ8 and CEM70/120, it's probably a better decision to spend a couple grand more and go with the higher brands like AP, SB, or the like.
@@JoesAstrophoto Yeah, I wish I had that kind of money lying around. It would make the process a lot easier. The Losmandy G11T would also be in a similar price range, but you get mixed opinions on these, too. I guess in the end it all comes down to an extended return policy ;-)
Thank you, je pensais que l'on pouvait faire la PEC seulement avec la raquette.
I am using an ASIAIR Plus is there any way to do PEC training with that or do i need to hook it up to my PC for that?
Hi Andy, I believe you need to hook it up to your PC to PEC train through EQMOD. Once you write the PEC curve to the mount, you should, in theory be able to go back to using the ASIAIR. You know the mount is using the recorded PEC if the light on the mount is flashing 3 times in a row. This all is assuming you have a EQMOD compatible and PEC writeable mount like the EQ6, EQ8, Orion Atlas, etc.
When recording PEC while imaging, and you have dithering on, does that affect the PEC curve?
Thanks for the comment Bill. I’ve not had any issues recording PEC with dithering on. You do want to make sure you don’t slew or do a meridian flip while recording however. Ask me how I know that one lol
@@JoesAstrophoto lol, thanks buddy!
Can I apply PEC in a Skywatcher EQM35 PRO? The way you explained it? I mean I need it more in a mount that is not belt enabled and not an EQ6
Thanks for watching and yes, the EQM35 PRO is capable of PEC and PPEC!
Brilliant video. Many thanks
Thanks Mike!
hello Joe thanks for the video .. I tried to do it but for me the red line only goes up! It's normal?
Hi Antonio, if you want to email me a screenshot I can let you know. My email address is under the about tab on my channel.
@@JoesAstrophoto WOW Yes THX!!!!
@@JoesAstrophoto it's in your email !!!
So this procedure via EQ ASCOM replaces what one would normally do for PEC via the hand controller, correct?
Yes, one and the same. I’ll be honest, I never used it with the hand controller. I actually used the hand controller 3 times and after going batty from trying to do a 3 star alignment, I found plate solving and never really used the hand controller again, but if you do use the hand controller then it’s the same you would do with it.
Great video Joe
Very helpful!😀👍
Thanks so much Simon! Glad it helped
Thanks for Video, looking forward testing it with my FLT132 i hope its help me improve guiding, Thanks guys!
Thanks Ernest, let me know if you have any questions and I'll do my best to help you out
This is looking very cool guys I think I have maybe a clear night tonight so I'm gonna try this on my HEQ5Pro. 👍
Cool Ollie, looking forward to hearing how it goes.
@@JoesAstrophoto Just had a go tonight unfortunately this is not available on the HEQ5 Pro, I check the website it's listed against the HEQ6 but not the 5. Oh well still got guiding anyway. Good to know though. 👍
@@OlliesSpace Hey Ollie, sorry to hear, I looked it up too and it doesn’t seem like HEQ5 has the encoders to save a ppec, but you can still do the autopec in EQMOD and save the file and use it each time if you wish.
@@JoesAstrophoto Cool I'll give this autopec a try. I did also read that when you do the PEC routine you shouldn't be dithering your image which I guess makes sense, so I'll try switching this off when I do it.
@@OlliesSpace Cool, just don't forget to turn dithering back on after or else you'll get the dreaded walking noise in your image. I hate that lol.
Would you need to redo pec when swapping to different focal length optics?
Hi Andy! You would not need to redo your PEC for things like that. The PEC is only correcting the periodic error in your worm gear. As your mount gets a lot of use it may start to change that error and you'd want to record a new PEC curve to re-correct. I don't really know how long that would be, probably depends on your mount and how often it's used. I did have a weird power outage that reset my mount and I found I had to re-record my PEC curve before.
Wonder if I can do this even though I use an ASIAIR PLUS ?
Hi, I’ve never used an ASIAIR, but you can test it out. After getting a permanent pec written to the mount, the mount’s led should blink red 3 times over and over. If after you turn the mount back on it’s not blinking that way, you should be able to enable on the hand controller and then it will be active while using the ASIAIR. If you do test it, please let me know if it works that way.
excellent explanation, thank you
Thanks Amrit! Glad it was helpful!
Awesome video! I see you have your Sidereal rate set at x0.20 why? And why not the Default x0.50 thank you again
Thanks Llamar! Actually that was Glenn's mount towards the end of the video we were looking at while recording the PEC curve. I'm assuming he had his set to x0.20 because that's what the Guiding Assistant in PHD2 recommended, but I'm not positive. I have mine set to x0.50 but I have vastly different conditions where I live than where he does. I'm not an expert by any means and I don't want to tell anyone the wrong thing, but I believe you want to be a little lower than optimal on your guide rate towards zenith and then as you approach the horizon PHD2 should start sending quicker pulses. Again, I'm not exactly positive on this and if anyone know better please chime in.
@@JoesAstrophoto thank you so much for the reply… I will try out the pec record again looks like I’m doing it wrong
@@llamarvasquez1803 It can be tricky, let me know if you need help
How do I add a pec curve to an eq6r pro when I only run off asi air, never connected to pc
Hi AK, I'm pretty sure it's not possible with the ASIAIR. I know it's possible to do it through the hand controller, but no idea how. The easiest way to do it is to hook it up to a laptop or pc long enough to record the PEC curve, then resume using your ASIAIR. Once the PEC curve is recorded to your mount, when it's on the power light will always blink 3 times in succession so you'll know it working since you won't have EQMOD to see it. I would say unless you're having some really bad RMS numbers, it's not worth the hassle.
I trained PEC on my Atlas EQ-G and it made my guiding a lot worse.. I will give this another go and see what happens.
Oh no Dennis, sorry to hear! How did the pec curve look before training? Please let me know if I can be of any help and I’ll do what I can to help troubleshoot.
@@JoesAstrophoto Thanks! I actually posted this vid to my club's facebook page but I do have a question- I heard you should near the meridian and celestial equator when you do this and you should be guiding. Is that true? If so, does the quality of your guiding setup reflect on the quality of your pec curve? It looked like he was tweaking guiding while the pec recording was going.
@@AstroDenny Thanks for sharing my video Dennis. I've heard a few things about having your dec at 0 degrees so close to the meridian however you want to make sure your mount does not do a meridian flip or slew while recording. I don't and I have a pretty smooth curve. You can mess with guiding a bit if you need to and you can dither as well in my experience. Hope that helps.
Fantastic Video
Thanks so much Andy!
Super helpful
Thanks Si!
Just moving into mono (once clouds disappear) so watching a lot of helpful stuff before it starts, mostly you and Glenn to be fair. Thought I'd do my own research beforehand, as I know Glenn will get hundreds of questions otherwise haha.
Keep making the vids mate, it's brilliant and so helpful
@@simrisks Thanks so much! You'll love the details you get from mono.
感谢分享！！！！
Glad you liked it Jian!