I've mostly used PHD2 with my belt modded and otherwise slightly tuned (and overloaded, which is why I recently upgraded to EQ8) HEQ5 as its PPEC guiding mode seems to work very well with this mount and routinely got under 1" RMS, usually around 0.8" and at best around 0.5", partially depending on the direction of the target (high DE targets guide better) and noticed that slight imbalance (east heavy) on RA does help quite a lot. I have a fixed remote location so I couldn't shift the weight when meridian flipping, but also the site is such that I would image mostly towards west of meridian so I balanced the rig accordingly. I use the target pier side option to image slightly before the meridian which extends the target area.

I did get the internal guider to work quite well too, but running PHD2 isn't really that much work and did give noticeable improvement as my imaging pixel scale is quite small so I switched to that. Also PHD guiding assistant and guide logs helped a lot in getting the settings tuned with less guess work. I use 0.5x guide speed and 2 or 3s exposures with OAG and Lodestar X2. With faster guide speeds the guiding became quite restless and with slower ones it didn't react quite fast enough to periodic errors so 0.5x was a suitable compromise.

"PPEC guiding mode", I guess that's from using PHD2 right? As eqmod does not have PEC for this mount(HEQ5pro), as far as I know.
www.indilib.org/devices/telescopes/eqmod.html
"PEC/PEC training is enabled in INDI EQMod for mounts which supports it, EQ8, AZEQ5/6, EQ6R too apparently."

From the Synscan manual:

Yes, it's one of the RA guiding modes in PHD2, Predictive Periodic Error Correction, where PHD2 "learns" the periodic error frequencies during guiding and gradually starts to correct them already in advance. This starts to help after one worm period, before that it behaves as normal hysteresis mode.

Are there ballpark numbers for how much PPEC improves guiding? For instance, I have two setups: an 80 mm F/5 refractor on an HEQ5 and a 203 mm F/5.4 RC on an EQ6-R. The first has a pixel size of about 1.7", the second om 0.7". If I can reach 1.0" guiding RMS on the HEQ5 then I wouldn't need the PPEC, right? On the second I usually have around 0.7" and better guiding RMS so perhaps there it could improve the RMS?


Wouter

For ballpark numbers my purely anecdotal experience is that on a typical night before the PPEC starts to work I usually get around 1" RMS and it gradually drops to around 0.8". This is with a similar setup as you have (8" TS RC with reducer, though my pixel scale is 1.02"/pix) but HEQ5 instead of EQ6-R. The most noticeable visible improvement in my case was that shape of stars is better thanks to less oscillation in RA direction due to PE. My DE error is small to begin with as I have fixed setup with good PA.

Having a read through that PHD2 best practice pdf openphdguiding.org/PHD2_BestPractices.pdf
They are talking about long exposure, 2s to 4s, when I tried that my mount didn't like it at all...

I typically use 2.0 sec exposures on both my setups and get the numbers I stated in an earlier comment. It truly seems that one's mileage may vary...

I get an average .35 tot rms on PHD2 using windows. On internal ekos and PHD on linux I get about 1.2 - 1.0
ONE TIME I got 2 hours of .35 average.... on the internal guider until I stopped it due to clouds. I never saw that again.

= (

I'm putting an ASI120MM on Orion 50m guide scope and will check how it guides with that. The Lodestar OAG guiding gets around ~0.8RMS on average, but I'll switch gears to see how guiding fairs.

My ASI120MM with a 50mm finder (162mm focal length) guides between 0.4 and 0.8 RMS. Using bin 2x2.
I have another (Datyson t7 clone) one on a 60mm (240mm focal length) gives around 0.5 and 0.7 also at 2x2 bin.

for the record - Im' using a 400FL and asi-290mm (and or lodestar SX). But was using the 1216 FL (OAG).

Thanx for this interresting discussion. Since i am suffering on bad guiding (internal) from time to time too, i´ll have a go on this settings you mentioned.

cheers
Niki