PHD2 trick for BETTER GUIDING! (Not multi-stars) 

You are a legend Cuiv. Why am I only hearing about this now? Can't wait to give this a go. Thanks

You really do a great job of explaining things so that us newbies can understand the problem you are solving. Thanks for another great video.

Great video as usual. Your contributions to amateur astronomy community have been incredible I can't thank you enough.

I thought you were gonna talk about the east heavey method and almost didn't watch the video. Never heard of this method so thank you very much. Glad your back.

Glad to see you back Cuiv, rested and sharp. Great vid, as usual^^ I'm using it since its implementation on a SW AZ-EQ6 with a SC 8", which cut my RMS and peaks in half. NB : polar alignment, weight distribution and calibration must be perfect.

So great to have you back to making astrophotography videos again, Cuiv! I've always learned so much from you and this video is no different. I will be giving this a go next imaging session. Thanks for all of your help and tips over the past couple years. Take care, Cuiv.

Absolutely amazing to have to you back mate! Just learned something new from you (again)… Will implement this as some as weather improves here in Melbourne … now I have to remind myself how to turn off PEC corrections from my mount - EQMOD😂

Keep up the fantastic work. Absolutely great video. Demystified some things for me! Gave me confidence to delve into the guts of PHD2.

So glad your back! You make my day. 😊

As usual another great video Cuiv. Thanks for taking the time to pull it together. BTW - You should enable DEC Backlash Compensation and back-off on your Resist Switch Aggressiveness a bit.

Excellent - cant wait to put this to use! As a beginner in the hobby I cant express enough appreciation for your videos - thank you Quiv!

Maan! So happy that you are back!! Thank you!

Thanks for the informative video. I have a really beginner level mount and this trick seems to help. I'm glad that you are putting out video's again. Keep up the good work.

Thank you Cuiv, I have been using PHD2 for years but was not aware of this. I will try it next session. You have a great way of explaining things and this is very helpful.

Another great video Cuiv I'll be using this setting in PHD2 next time I image as my guiding can be very hit & miss sometimes, thanks for your time uploading & explaining this clear skies!!

I m so thankful that there are people like you out there. What a legend !!!

I am happy to see your videos back. Theorical and practical is what I love. This is what defines an engineer. Keep going.

Thank goodness your back Cuiv, as well as turning me on to N.I.N.A your videos have steered me through most of the problems I have come across as a beginner astophotographer. Thanks for all your time ,effort , and enthusiasm.

Awesome! I've been using periodic error correction in EqMod up until now but I've had to manually re-record it every time I set up my rig for a night of imaging. Being able to tick a check-box in phd makes so much more sense. Thanks and keep up the great work - it's really appreciated by us noobs!

Amazing tip Cuiv! I cannot wait to try this. I've always suspected a slight issue with the worm gear on my EQ6. I had no idea about the Log viewer, now I can check it out and see what's going on. Thank you!

Brilliant, Cuiv! You’ve changed/ improved our imaging forever! Award this man a medal!

Delighted you are back making videos Cuiv 😊

This video dropped just in time! I literally looked up which PHD2 algorithms were better to use a couple of days ago and ended up settling for PPEC, which was one of the most recommended. Glad to know how that works now :)

Thanks Cuiv! What a brilliant educational vid. I will try out this PPEC on my SW HEQ5 Pro Mount the next time i'm imaging

Fantastic information Cuiv. I have learned a lot from watching your videos. You rock it!

Thank you Cuiv ! As always useful information!

What a great guy! Thanks for still MORE helpful information I can put to work easily and quickly. And I’ll even sort of understand what I’m doing!

Great video. I've known about PEC and PPEC since researching mounts when first getting into AP. But it all seemed too technical to get into and because my guiding (for the most part) was fine. After watching your video I realise that I can flick the switch in PHD and do the job there. Thanks Cuiv

Note that KStars has this as well; I also just implemented a feature to decouple the predictive corrections from the guide camera corrections, so you can take long guide exposures if necessary, while responding to predicted PE much more frequently :)

Great video, Cuiv!!! For those reading, it is possible to right click in the PHD2 log viewer to do a frequency analysis and it will tell you the periodic error to help in analysis. Great for talking with the PHD2 devs or mount support gurus as well!!

Awesome! I will definitely do this. I have a CEM 60 and have really wanted to have it guide a little better. Thanks!👍

That little change is amazing. My guiding went from about 0.85 arcseconds to about 0.55 arcseconds. absolutely amazing!!! thanks for the tip.

Thanks so much for sharing this Cuiv! I have some eccentricity in my EQ6R RA motor that causes a 120s PE that I can't get rid of with the mount's bulit in PEC, and this should be a great way to deal with that. BTW you probably know that is but you can use the "analyis" feature in the guidelog to look at the period of that sine wave.

You keep making us smarter! Thank you.

Cuiv, there is nothing lazy about the depth of what you’re sharing and for the engineer audience you can’t say too much! Now i have to wait for the next clear night to give this a try. Thank you!

Discovered this algorithm back when I had my CGEM, didn't help too much, but it really did when I got my EQ6R.

Cuiv, very well done explanation of cause and effect. This was done so well, I would suggest you consider doing slightly expanded version some Sunday on The Astro Imaging Channel (TAIC). They are always looking for great presentations.

This is amazing sir...❤ always Crystal clear informations.. all the very best sir..❤

Very sophisticated and well explained!

Thanks for the tip!! Will check my guiding graphs. Whether is crap so it’s a great time to fiddle around with settings and make improvements. Great video hope your skies are clear.

Didn't know about that one Cuiv!. Thanks for that, I will definitely be giving it a go next clear night. I do have sine wave discrepancies on my guiding for sure.

Thanks a lot!! I use to have to record my pec in the beginning of all of my sessions and loose about 16 minutes ... I can't wait to try this 👍👍

Appreciate all you do for the astro community. Thanks, Cuiv !!

Excellent tip and explanation. Off to check my PHD2 log.

0.51 RMS total is a great result. Thanks for going over this.

Great work putting this out there Cuiv! - I'll be giving it a go for sure! :-D Clear skies!

Fantastic tutorial with clear explanation! Thank s again!

Great job explaining what is going on with Permanent PEC. I was using Pempro for my PEC curves and I was guiding at the same time with PhD2.....I did not realize a battle was going on between the two software systems but that makes sense.....actually too much sense. Keep up the awesome tutorials and there is no need to keep them brief on my accord. R E T I R E D !

Thank you, Cuiv. I will certainly give this a shot.

Thanks for the tip. I will try this out. I am trying to guide out a C14 and the RA does show some periodic fluxes. I hope setting to predict PEC setting will help.

Another pearl of wisdom. Great video, Cuiv.

Great tip! Never heard of it before! Gonna try it soon, thanks!

Amazing video description Yannik. Thank you so much for making our hobby easier. Clear skies.

Excellent video Cuiv! I kind of wondered if ppec and phd2 were fighting each other or not, so I quit enabling ppec. I will try this. Thanks!

I love the silly click-bait sub-title in the thumbnail!!!

Great information. Thanks for sharing.

I simply love these types of astro hacks! Gonna give it a go on next opportunity! Thanks Cuiv!

Great video Cuiv. I've been using the PEC algorithm with both my AVX, and Losmandy Gm811G mounts, and found that it can give a tremendous improvement. The losmandy mount works much better when the PEC period is set to the worm period, with "auto" disabled. The AVX works best with the PEC programmed into the mount, and by using PHD2 PEC set to auto. The AVX has much more noise in the mechanics and benifits from using both.

Ha! thanks for this 😊 didn't know about it 🙂 I am looking forward to implementing it into my next session :) have done a lot of trials on lucky imaging and capturing with my guiding cam while unguided. been trying to figure out the best way to use livestacking as to filter the crappy frames and stacking only the very best using a FWHM filter and also an alignment filter!

Now if only the acronym for Predictive and Permanent Error Correction weren't both PPEC. Great video on a great phd2 feature, glad to see you're back!

Like every one here said: Another great video!! We missed you ! Question could you explain the chart you show at 1:34 ? Also, there's no advantage in getting a mount with built in PPEC?

Great explanation! I use this feature but did not know why. Thank you for the theory. It really helps!

Great video, Cuiv!! I've been using PHD2's PPEC algorithm for over 2 years with my iOptron GEM45 mount, and can't live without it now. The guide performance in RA axis is no match when you look at the guide graphs on the guide log side by side, and would highly recommend any of the beginning astrophotographers to use this algorithm on PHD2. I usually guide with an OAG and the shortest focal length I use is about 900mm+. On such system, I use higher aggression and higher values for retaining the periodic error on the advanced (brain) settings due to terrible seeing conditions in the middle of Seoul. I would also highly recommend not to use auto find setting for the worm period. I found that guesses the PHD2 is quite finicky, and I sometimes get something like 2.5 times the worm period (how does it guess such a figure!!) and get terrible guiding results if I leave it at auto. I use the worm period in the spec sheet of the mount, and it works perfectly

Very helpful Cuiv .. I will give that a go!

Fantastic! I’m definitely going to try this on my EQ8R Pro. Thank you! Seems odd that the guiding assistant doesn’t already have this as one of its suggestions!

Wow, I was actually thinking of predictive algorithms, more for my Equatorial platform. Didn’t knew PHD 2 already has it. Thanks a ton for this video.

Even though I have a ZWO AM5, I still watched and past it in to the guy that bought my old iOptron iEQ30pro mount (a pretty nice mount too). But, what I appreciated is your comment about going out and do some testing during the full moon. I kinda pass on around 4-5 nights before and after the full moon. Makes sense, thanks!

Great tip, I will try this, thanks

thank you, very valuable information!

Using PPEC and PEMPro together seems to work well with my Losmandy G11 with Gemini. The 240s error is reduced by PEMPro to some degree but the PPEC picked up the most of the residuals. But PPEC does not seem to have the ability to reduce multiple overlapping worm harmonics, e.g. it will handle the 240s error well but not the 120s, 80s or 60s; all fundamentals of the original worm period. A more advanced PPEC that could handle more frequencies at once would really be worth while. Thanks again for your feedback. John

great explanation Cuiv, I wish the asiair had this function it would be an actual gamechanger!

Thanks for that Cuiv, I will give it a go next session. Pete.

welcome back !!!

That comment about looking at the DEC guiding to assess seeing across sessions is something I've noticed too. It's so easy to get a great polar alignment with today's software that it seems like DEC corrections are few and far between - all that jitter on the guiding error graph is just "seeing" noise. I need to try this, or do the PPEC thing to try to get my RA error close to the DEC error. Thanks for the reminder.

You sir, are a scholar and gentleman!

Great tip Quiv, didn't know that so have to try this out if I can get some clear skies here in Belgium. Question though, your title says "not multi stars" but in the video you write to enable multi star guiding ?

Thank You, Cuiv. Little Pearls like this make life better. I'd say after the multi-Star guiding, this can really help automate the guiding process. A friend of mine gave multi-star out as soon as PHD2 allowed it to be given. He was a part of the Beta team helping to work out the release. I do have a question though, why do you have your settings so broad where you show Plus/Minus of 30°? I try to run my graph much, much lower so my graph is choppier. Mainly just curious, because I've observed this a lot when folks start demonstrating their graph's. Or is it to get a much broader view of time? Love your tutorials! I've already applied this to my "Mount Computer" that I use outside. (I remote operate most of the time. I'm old, and the cold bothers me.) Again, Thank You!

Very nice... Thank you.

This is a reason I get 0.5-0.6 on AVX with 25Lb load. I experimented with different algorithms; it gave best results.

Thanks for yet another great video! Can this be applied to mounts like harmonic drive or those belt driven Avalons? The term PEC still relates to something periodic… cheers

This is very useful Cuiv. Have you compared phd2 pec results vs doing a pec training within eqmod?

Great advice Cuiv! I have the Orion HDX 110 Mount and routinely get around .52 arc seconds total error, which is already really good so I can imagine what predictive PE might do. I have been known to get a quarter arc second before but I'm not sure why it was so good. I did add around twelve new calibration steps. Perhaps that was it? Thanks for the advice.

With the EQ6-r and EQMOD, PPEC and guiding don't fight like they do on iOptron mounts. The combination works great together! The same is true or Astro-Physics mounts.

Thanks for sharing this video Cuiv! You mention "not multi-star" but wich is better to use with Predictive PEC, sigle star or multi star?

Great video and explanation! Is Phd2 smart enough to learn this while doing short exposures and dithers, or would it benefit from being left alone to guide uninterrupted for 10-15 min before you start imaging?

Been using Predictive PEC with my AZ-EQ6 for a while now and it seems to be the best algorithm of the bunch. My RA worm has a very aggressively bad part on it, maybe as much as 10 arcseconds within 30 seconds and it actually still works surprisingly well. I can see a dip in performance once every worm period but its corrected much better than with the simple hysteresis algorithm which really couldn't do anything at all to such a sudden change in tracking rate.

Wow Cuiv that is a really flat graph! That CEM60 looks at first like overkill for a C6 but you just showed that a beefy mount is needed for the best stability! Thanks for showing everyone this feature because it is not enabled by default. I had been having issues with my CEM26 and I realized it was just loaded too heavy for AP even with the setting you showed (Predictive PEC) so I "broke" down purchased a HEM27EC (can handle up to 14kg!!!). I use a iGuider but it doesn't fit this mount saddle until I receive a part I purchased from iOptron support 😞. In the mean time I have to image unguided but wow I am able to image 5min subs @300mm with NO GUIDING and round stars! I just use the NINA Direct Guider for dithering but it is nice imaging without worrying about guiding issues! I still have issues with wind gusts which guiding seem to help with so I will guide again when I get the part. I suppose now I could have gotten a used CEM60 but I am now spoiled with a mount and head that only weighs a total of 6 kilos! As always awesome video! CS!

I recently upgraded from DSLR to QHY 183 M with the 7 position filter wheel but I'm stuck finding the right fitting to connect my Televue Paracorr type 2 coma corrector to the QHY filter wheel. Any experience with that coma corrector and a Newtonian?

Many thanks!

Thank you for all your help with astro gear! I have learned so much from you! Question: I have aa C14 on the CEM60EC mount (which has RA encoder) Do you know what PHD2 algorithm I should use with the encoder? Would I be better off to turn the encoder off and allow PHD2 to correct for both mount axis errors? I am running at F7 with the ZWO071MCpro camera at bin2 and off axis guider ZWO290mm mini. Thanks

Interesting Video. Just wondering do you keep it set on the "predictive PEC" option for all future runs or change it back to the other setting?

Fantastic video!! Honestly this has been very useful and I look forward to seeing if I can improve my guiding with this method… however I use ASiair plus, do you know if the ASiair has this setting? I’ve not noticed in the settings, but I do notice a similar wave pattern on my guiding… I use an EQ3 pro mount. Thanks

Friend: What's that sinusoidal curve right there? Cuiv: I have a bad worm. Friend: Shouldn't you see a doctor for that, worms and all? Great job! I have put ups two todmorden piers so with a quick set up and take down I can now pay more attention to these things that will tighten things up! Thanks!

Nice video as always. I looked for the optional algorithns in the settings and the pull down menu was inactive (greyed out if you will). Is this s version thing or is there another stting that inhibits this? Also, do you have the PEC playback (I have an AVX mount) active when you guide like this?

We love your videos….and you too.

I have exactly this problem with AR, but I use ASI AIR, do you know if there is a way to correct it on ASIAIR as you did with PHD2?

Great video. One mystery for me on all these settings is which software does it in a multi-software environment? I run stellarmate as my core O/S but get it to use PHD2 as the guiding interface. Do I do these settings in PHD2 or Stellarmate, do you know if Stellarmate overides PHD2 settings?

I have the same thing on cem26 :) thanks for the trick :)

Amazing. I’m petitioning ZWO to get this on the ASIAir!

I wonder if the periodic error is changed by different loads. What I'm trying to ask is, say i do planetary one day and the next day I put a heavier camera and filter wheel on? Will predictive PEC save more that one profile or would you say that this function only depends on the error in the gears, irrespective of the load on the mount? If it does make a difference and PHD2 only saves one profile, perhaps this would be an upgrade to propose to the creators of the program?