PHD Autoguiding problem

[davies07]

Your tracking graph looks to me like instability - too much gain for the load. There are short periods where tracking seems to be ok then it takes off, repeatedly making too big a correction and overshooting, then trying to correct that and overshooting in the other direction. My first response would be to turn down the aggression in RA and DEC. Also, make the values of Minmo bigger in both axes, say 0.5 in each axis. This stops the guide software responding to very small errors - currently 0.18, too small.  

I would try the built-in PHD utility Guide Monitor (from memory) under the Tools menu. This turns off the guiding but PHD watches how the mount tracks the sky and monitors the star movement. This takes several minutes to finish but PHD then gives you a readout of your tracking accuracy, backlash and polar alignment. It also gives you a recommended set of settings and will apply then automatically with one click. I find this works well. 

I need to close for tonight. Good luck. Let me know how you get on tomorrow. 

David

[malc-c]

Firstly, that's a nice set up.  With the weight of the guidescope you might find that the balance is close, but I still feel that this may be the issue given the fact the mount seems to be stalling in the southernly direction when trying to calibrate.

I'm not 100% familiar with the newer mounts that have built in USB connection on the synscan controller, but I'm assuming that it provided the same function as an EQDIR cable and allows a PC to control the mount.  If so, having the handset connected as well might have some bearing.

I agree with David, that the traces do appear to be aggressive overcorrections, but then I always thought that was the purpose of calibration and running the utility to track the star and work out the optimum values and backlash compensation, both of which you have done.  Maybe change the RA and DEC pulse guiding rates in EQMOD to x0.2 and then see how it goes, and then increase this step by step until the corrections become too aggressive.  You would need to try a calibration between each test  

It's not clear from the images as the cabling is not easy to follow, but it looks like you have some  very long USB cables coiled up by the handset.  If these are 5m passive cables then this can also lead to communication loss.  Can you also confirm that you have a USB cable connected to your computer and the synscan unit, and a separate usb cable from the camera to the computer, or do they connect is some other way?

Just to cover the basics - with the handset connected and the USB lead removed, set the handset to speed 9 and operate the mount in NSEW as far as you can rotate the mount in each axis , taking care when the counterweight is up and the scope down.  If the mount moves OK, then disconnect the handset, connect the USB lead to the computer and launch EQMOD.  set the speed step to 4 and repeat the test, if all goes well then this confirms that EQMOD can control the mount and the custom configuration entered is correct.  The slew speeds should be about the same regardless of if the handset or EQMOD is used.  - This means that the mount is functional and nothing is binding or slipping, or causing the motors to stall.

Then its just a case of playing with the pulse guiding settings in EQMOD and PHD2.  David picked up on your location, which must put Polaris low on the northern horizon.  Maybe using the southern celestial pole may be better.  I don't know if it has any bearing, but maybe EQMOD is expecting the mount to be facing South rather than North given your latitude ?- then again it may not...its not as if the mount is effectively in an ALT / AZ position.

[michael8554]

From the GuideLog, the good news :

You have Guiding selected.

The selected Guide Rates are 9.5arcsec/sec, which is fine.

You eventually started Calibrating at around Dec=0,   Dec = -62 and Dec = -54 are not necessary when you have an ASCOM connection.

The bad news:

To emphasise what Malcolm has shown, your Calibration axis are almost opposite each other, instead of at 90 degrees to each other.

So every RA move is echoed in the Dec axis and vice-versa.

Guide Assistant reported PA error to be 26arcmins - did you improve that ?

PA figures during guiding attempts varied widely, but with the poor Cal it's hard to say what the real figures were.

Reported guide speeds are 23 to 27 arcsec/sec (although the mount is set to 9.5), which means Calibration is in only 4 steps instead of 12, the guide rate in EQMOD needs adjusting I'd guess.

I'm not a EQMOD or ST4 user, so I'm not sure why you have a ST4 connection on the guidecam when ASCOM guiding - is that necessary ?

Looks like that ST4 cable is about to snap, and may already have broken connections:

Rotate the guidecam so that the ST4 and USB sockets are at the bottom, and tie the cables in a smooth loop to the main scope, and a larger loop to the top of the tripod.

PHD2 will compensate in Cal for the "upside down" guidecam.

UNTIL YOU GET A GOOD CALIBRATION IT IS POINTLESS TRYING TO GUIDE.

I gather that Williams Optics make quality scopes, but their scope mounts are an engineering disaster.

Michael

Edited April 11, 2021 by michael8554

[Wael Hassan]

7 hours ago, davies07 said:

Your tracking graph looks to me like instability - too much gain for the load. There are short periods where tracking seems to be ok then it takes off, repeatedly making too big a correction and overshooting, then trying to correct that and overshooting in the other direction. My first response would be to turn down the aggression in RA and DEC. Also, make the values of Minmo bigger in both axes, say 0.5 in each axis. This stops the guide software responding to very small errors - currently 0.18, too small.  

I would try the built-in PHD utility Guide Monitor (from memory) under the Tools menu. This turns off the guiding but PHD watches how the mount tracks the sky and monitors the star movement. This takes several minutes to finish but PHD then gives you a readout of your tracking accuracy, backlash and polar alignment. It also gives you a recommended set of settings and will apply then automatically with one click. I find this works well. 

I need to close for tonight. Good luck. Let me know how you get on tomorrow. 

David

Thanks for your advice...i was thinking in the aggression values...i ll try it tonight and come back to u 

[Wael Hassan]

7 hours ago, malc-c said:

Firstly, that's a nice set up.  With the weight of the guidescope you might find that the balance is close, but I still feel that this may be the issue given the fact the mount seems to be stalling in the southernly direction when trying to calibrate.

I'm not 100% familiar with the newer mounts that have built in USB connection on the synscan controller, but I'm assuming that it provided the same function as an EQDIR cable and allows a PC to control the mount.  If so, having the handset connected as well might have some bearing.

I agree with David, that the traces do appear to be aggressive overcorrections, but then I always thought that was the purpose of calibration and running the utility to track the star and work out the optimum values and backlash compensation, both of which you have done.  Maybe change the RA and DEC pulse guiding rates in EQMOD to x0.2 and then see how it goes, and then increase this step by step until the corrections become too aggressive.  You would need to try a calibration between each test  

It's not clear from the images as the cabling is not easy to follow, but it looks like you have some  very long USB cables coiled up by the handset.  If these are 5m passive cables then this can also lead to communication loss.  Can you also confirm that you have a USB cable connected to your computer and the synscan unit, and a separate usb cable from the camera to the computer, or do they connect is some other way?

Just to cover the basics - with the handset connected and the USB lead removed, set the handset to speed 9 and operate the mount in NSEW as far as you can rotate the mount in each axis , taking care when the counterweight is up and the scope down.  If the mount moves OK, then disconnect the handset, connect the USB lead to the computer and launch EQMOD.  set the speed step to 4 and repeat the test, if all goes well then this confirms that EQMOD can control the mount and the custom configuration entered is correct.  The slew speeds should be about the same regardless of if the handset or EQMOD is used.  - This means that the mount is functional and nothing is binding or slipping, or causing the motors to stall.

Then its just a case of playing with the pulse guiding settings in EQMOD and PHD2.  David picked up on your location, which must put Polaris low on the northern horizon.  Maybe using the southern celestial pole may be better.  I don't know if it has any bearing, but maybe EQMOD is expecting the mount to be facing South rather than North given your latitude ?- then again it may not...its not as if the mount is effectively in an ALT / AZ position.

Yes i have 5 M usb cable from mount to my pc.... I have a question here ...is the Pulse guiding the same as guiding rate in mount ? 

[Wael Hassan]

10 minutes ago, michael8554 said:

From the GuideLog, the good news :

You have Guiding selected.

The selected Guide Rates are 9.5arcsec/sec, which is fine.

You eventually started Calibrating at around Dec=0,   Dec = -62 and Dec = -54 are not necessary when you have an ASCOM connection.

The bad news:

To emphasise what Malcolm has shown, your Calibration axis are almost opposite each other, instead of at 90 degrees to each other.

So every RA move is echoed in the Dec axis and vice-versa.

Guide Assistant reported PA error to be 26arcmins - did you improve that ?

PA figures during guiding attempts varied widely, but with the poor Cal it's hard to say what the real figures were.

Reported guide speeds are 23 to 27 arcsec/sec (although the mount is set to 9.5), which means Calibration is in only 4 steps instead of 12, the guide rate in EQMOD needs adjusting I'd guess.

I'm not a EQMOD or ST4 user, so I'm not sure why you have a ST4 connection on the guidecam when ASCOM guiding - is that necessary ?

Looks like that ST4 cable is about to snap, and may already have broken connections:

Rotate the guidecam so that the ST4 and USB sockets are at the bottom, and tie the cables in a smooth loop to the main scope, and a larger loop to the top of the tripod.

PHD2 will compensate in Cal for the "upside down" guidecam.

UNTIL YOU GET A GOOD CALIBRATION IT IS POINTLESS TRYING TO GUIDE.

I gather that Williams Optics make quality scopes, but their scope mounts are an engineering disaster.

Michael

I disconnect the st4 cable.... whats shown in the pic u attached is the usb cable and yes u are right ...i should rotate the camera to release the tension in the cable.... I d like to know how to correct the periodic error in my mount ?  ANd how to get perpendicular axis on the guide log .

[teoria_del_big_bang]

14 minutes ago, michael8554 said:

I'm not a EQMOD or ST4 user, so I'm not sure why you have a ST4 connection on the guidecam when ASCOM guiding - is that necessary ?

Again this is all a bit flakey in my memory but when using ST4 with PHD2 don't you select "On Camera" in the profile ?
But as "Mount = EQMOD HEQ5/6 (ASCOM), connected, guiding enabled" is in the guide log then it looks like EQMOD will be moving the mount to compensate for guiding, BUT the camera will also put out guiding pulses whether used or not and the mount will receive them so would this cause an issue trying to use both EQMOD and ST4 ??
 

So as you say in previous post I would definitely remove the ST4 cable and let EQMOD compensate the mount.
This may not cure your issue but its wrong so needs correcting (I would think).

Steve

[michael8554]

3 hours ago, Wael Hassan said:

Thanks for your advice...i was thinking in the aggression values...i ll try it tonight and come back to u 

Not worth messing with the default PHD2 settings UNTIL YOU GET A GOOD CAL.

3 hours ago, Wael Hassan said:

is the Pulse guiding the same as guiding rate in mount ? 

ASCOM Pulse Guiding Settings in EQMOD

3 hours ago, Wael Hassan said:

I d like to know how to correct the periodic error in my mount ? 

Why on earth are you asking that when you have so much wrong with your guiding. Stop sidetracking !

[malc-c]

OK for now, forget about the periodic error... you need to go back to basics as I suggested.  You need to take each step suggested at a time and confirm that each step works.  Then focus on getting PHD2 tracking.  I would even go as far as suggesting all existing profiles are deleted and you start with a fresh install of PHD2.

Get the calibration right.  Try and work out if the cause is an overly aggressive setting for the pulse guiding in EQMOD.  Oh and please try and confirm or answer the questions we are putting to you, such as I asked for clarity on how you have the camera and mount set up, only to receive half the information...

5m passive cable is on the limit for USB, and I personally will only use 3m passive cables maximum and switch to active at 5m.  The problem might be due to data drop out because of the cable.  For now, try replacing the 5m cables with shorter ones whilst testing.  Presumably another 5m cable is used for the camera, so the same applies.  Once you prove the transmission is OK with the short ones then repeat with the longer ones to confirm that the doo indeed work.

Think of this as a detective story, eliminate the suspects one by one and eventually you'll find the culprit...

Edited April 11, 2021 by malc-c

[davies07]

Hi Wael,

I confess, I find it difficult to follow threads such as this when many suggestions and recommendations are being posted, and you might be making changes to your setup along the way. So, I thought I'd just make a summary of what I've seen in the various posts. By the way, I've had a look at your guiding log using the PHD2 Log Viewer utility, which you can download for free.

So this is what I've observed in the photos and screen shots and these thoughts might trigger a response from others who are trying to help:

You are guiding via EQMOD so are not using an RJ 45 cable between guide camera and mount. That fine. That's the way many of us do it.

You Guiding Assistant screen shot shows a polar alignment error of 3317 arc minutes. This seriously wrong, 55 deg! How are you doing the polar alignment? If this is the PA error, then I think it could account for the poor guiding calibration.

You are using a telescope with 120mm focal length and a guide camera with 3.7um pixels. This gives an image scale in the guide camera of 6.4 arc sec per pixel. This will make the guide stars look small and blocky. rather than fuzzy discs. I assume the guide scope is properly focussed and you can see stars on the PHD screen. 

The high frequency star motion in the Guiding Assistant screen is showing really large values of high frequency star motion. I don't understand this.  

The guiding log confirms your guide telescope focal length of 120mm, pixel scale of 6.45 arc sec per pixel and exposure time of 2.5s

Some suggestions:

You need to look at the polar alignment. The celestial pole is around 30 deg altitude above your northern horizon. The elevation of your RA axis when parked in the home position, should be the same as your latitude - you should be able to get a utility for your phone to measure this by laying your phone on the mount. You can use Scopefocus to do the polar alignment; it works well. If, however, you can't see Polaris, I suggest you set the elevation of the mount as suggested, and then focus on a bright star to the south and and use drift alignment to set the azimuth of the mount. I think PHD has a utility to do this. 

I would set the guide camera to be upright in the guide scope when the mount is parked - pointing at Polaris.  I think the cable will then hang vertically down. Once set, you should not move the guide telescope or camera relative to the mount.   

I wouldn't worry about periodic error correction for the moment until you've got basic calibration and guiding working properly. But when you come to it, EQMOD will do it automatically for you.

 Finally, here is a screen-shot from your guiding log which confirms some of these findings:

 

Interestingly, the guiding is converging after doing a Guiding Assist run., but the comment on polar alignment is key, I think.

David

 

 

[Wael Hassan]

3 hours ago, malc-c said:

OK for now, forget about the periodic error... you need to go back to basics as I suggested.  You need to take each step suggested at a time and confirm that each step works.  Then focus on getting PHD2 tracking.  I would even go as far as suggesting all existing profiles are deleted and you start with a fresh install of PHD2.

Get the calibration right.  Try and work out if the cause is an overly aggressive setting for the pulse guiding in EQMOD.  Oh and please try and confirm or answer the questions we are putting to you, such as I asked for clarity on how you have the camera and mount set up, only to receive half the information...

5m passive cable is on the limit for USB, and I personally will only use 3m passive cables maximum and switch to active at 5m.  The problem might be due to data drop out because of the cable.  For now, try replacing the 5m cables with shorter ones whilst testing.  Presumably another 5m cable is used for the camera, so the same applies.  Once you prove the transmission is OK with the short ones then repeat with the longer ones to confirm that the doo indeed work.

Think of this as a detective story, eliminate the suspects one by one and eventually you'll find the culprit...

Thank you and i am sorry i thought i answered all questions....i connect the Camera to pc by usb cable and the mount to pc by usb cable ....i use eqmod to move the mount ....i create a profile in phd according to phd best practice.... tonight i ll delete all profiles and use shorter cable and start again

[Wael Hassan]

1 hour ago, davies07 said:

Hi Wael,

I confess, I find it difficult to follow threads such as this when many suggestions and recommendations are being posted, and you might be making changes to your setup along the way. So, I thought I'd just make a summary of what I've seen in the various posts. By the way, I've had a look at your guiding log using the PHD2 Log Viewer utility, which you can download for free.

So this is what I've observed in the photos and screen shots and these thoughts might trigger a response from others who are trying to help:

You are guiding via EQMOD so are not using an RJ 45 cable between guide camera and mount. That fine. That's the way many of us do it.

You Guiding Assistant screen shot shows a polar alignment error of 3317 arc minutes. This seriously wrong, 55 deg! How are you doing the polar alignment? If this is the PA error, then I think it could account for the poor guiding calibration.

You are using a telescope with 120mm focal length and a guide camera with 3.7um pixels. This gives an image scale in the guide camera of 6.4 arc sec per pixel. This will make the guide stars look small and blocky. rather than fuzzy discs. I assume the guide scope is properly focussed and you can see stars on the PHD screen. 

The high frequency star motion in the Guiding Assistant screen is showing really large values of high frequency star motion. I don't understand this.  

The guiding log confirms your guide telescope focal length of 120mm, pixel scale of 6.45 arc sec per pixel and exposure time of 2.5s

Some suggestions:

You need to look at the polar alignment. The celestial pole is around 30 deg altitude above your northern horizon. The elevation of your RA axis when parked in the home position, should be the same as your latitude - you should be able to get a utility for your phone to measure this by laying your phone on the mount. You can use Scopefocus to do the polar alignment; it works well. If, however, you can't see Polaris, I suggest you set the elevation of the mount as suggested, and then focus on a bright star to the south and and use drift alignment to set the azimuth of the mount. I think PHD has a utility to do this. 

I would set the guide camera to be upright in the guide scope when the mount is parked - pointing at Polaris.  I think the cable will then hang vertically down. Once set, you should not move the guide telescope or camera relative to the mount.   

I wouldn't worry about periodic error correction for the moment until you've got basic calibration and guiding working properly. But when you come to it, EQMOD will do it automatically for you.

 Finally, here is a screen-shot from your guiding log which confirms some of these findings:

 

Interestingly, the guiding is converging after doing a Guiding Assist run., but the comment on polar alignment is key, I think.

David

 

 

Thanks David....i use sharpcap for polar alignment and got excellent result...i dont know why it gives me that large error in PA with PHD.

I adjust the usb cable for guide camera as u suggested.

 

[Wael Hassan]

Iam doing now imaging session and i took some photos to record what i was doing .

I started by making polar al9gnment with sharpcap i got excellent result but i want to say here that the final step in sharpcap alignment is to rotate the RA axis by 90 degrees then make the adjustment untill u get the excellent PA ...after that i returned the RA axis to 0 angle but it gives me Fair PA result so should i depend on the 90 degrees result or the 0 degree result ?

I made new profile in PHD and new cal9bration i got perpendicular axis so i slew to my target which is IC 4606 and start guiding there.... i got the best RA and DEC curves through the last 4 weeks ....i know it may not be good bit its better than any curves i got before....i changet MINMO and Aggression values but i found the default setting is the best for my curves..... i start imaging the exposure was for 3 minutes i got very nice round stars.

[Budgie1]

It's looking better but there are a couple of things which may improve it.

You are still using the MinMo of 0.18 in PHD2 for Dec & RA, change this to somthing like 0.25 or 0.30 .

Also try changing the camera refresh rate to 2.0s from 2.5s (next to the STOP button on the bottom line of the PHD2 page).

As for PA, in the third photo down, looking at the front of the mount, is the RA in it's 0° position in this photo? Only it look off to the right. Normally the counter weight bar would line up with the front leg of the tripod, the one with the N on it. If this is your starting point for PA then  it could be thrown off by not having it in the correct Home Position to start with.

When I do PA with SharpCap on my EQ5 mount, it normally only moves seconds from Excellent to Good when I rotate the RA axis back to the Home Position. Yours is by minutes, so something isn't right with that and it may be worth running the PA again using the reset function.

Instead of relying on the setting rings for your 0° position, set the Home Position (here's a video for you) using a spirit level and put a line across the DEC & RA axis on the mount when it's in the Home Position so you can always get it back there. The setting rings aren't that good on the EQ3 & EQ5 mounts and can move.

You're making progress, so keep going and we'll get there.

[michael8554]

GuideLog ??

Much, much, better.

Your Cal has a much improved angle error, and PHD2 shows the Cal as "Acceptable", indicated by the Cal icon on the bottom line of the main window display being Green, instead of Red for Fail.

And the reported Dec and RA Guide Rates are now sensible values, albeit a little different.

6 arcmin PA error is just about useable, 5 or less would be better.

Equipment Profile looks to have the correct selections now.

I can't read what setting you have for the EQMOD Pulseguide settings, screen grabs are much better than screen shots.

Best to run the PHD2 Guide Assistant to advise the MinMove settings for each night's seeing conditions.

And allow it to measure Dec Backlash and set the PHD2 Dec Backlash Compensation.

Alter the PHD2  x:400 setting to give a more spread-out horizontal scale to the graph, it's much too bunched-up to read easily.

You could start to practice your image processing skills by at least posting images that aren't rotated 90 degrees.

[malc-c]

I would certainly be happy with a graph that was on the +/- 4 second scale... 

There is not a lot more to say as the other contributors have already covered things.  As for the PA issues, it could simply be that the guidesope is not 100% parallel to the RA axis.  But that is something you may never get, and you may end up making things worse.  I've covered how I aligned my guide scope with the main camera which got me close enough to 10" alignment.

At least you're getting results this time - well done

[davies07]

I think this looks promising. Polar alignment error is larger than I would hope to see; something less than 1' would be better. I assume that you are using the imaging scope and camera to do the polar alignment. You are getting images and they look good. 

The one thing that strikes me is the image scale of the guide scope. Your guiding errors are around 3.2" r.m.s. and is filling the chart at 4 arc sec scaling, but 3 arc sec is just half a pixel on your guide camera. I find it difficult to think how guiding accuracy might be improved without increasing the focal length of your guide scope or substituting a guide camera with smaller pixels. If we suppose star images in your skies might be 6 arc sec across, your guide camera has just one pixel filled. I imaging the star images in the guide scope might look like little crosses. 

Your guide scope is F/4 so it would be reasonable to add a X2 Barlow and double the focal length to 240mm. you would still have good brightness at F/8 and it would half your guiding image scale and guiding errors should also be halved.

I'm not very happy with how slowly the RA errors are being pulled in. The guider is sending commands but the mount seems slow to respond and the AGR value seems to have little effect, although at 35 the response is noticeably slower.  I wonder how much of the excursions we see on the display are due to noise from PHD calculating the centroid of the star image at the image scale, rather than real tracking errors - all the motion we see on the PHD chart is inside one pixel. I would certainly reduce the update time from 2.5s to something a little quicker - 2, 1.5 or even 1.0s if your sky seeing is reasonably quiet. The risk would be that we would be trying to get the mount responding more rapidly to noise.

Here's a thought. Just as an experiment make the imaging scope the guide scope and see what sort of guiding performance you get from it. That would show how a longer focal length guider would perform. 

David

[Wael Hassan]

5 hours ago, michael8554 said:

Alter the PHD2  x:400 setting to give a more spread-out horizontal scale to the graph,

Thank you so much ... but i am still beginner and dont understand the meaning of X: 400 setting 😅 ?!

[malc-c]

43 minutes ago, davies07 said:

 

Here's a thought. Just as an experiment make the imaging scope the guide scope and see what sort of guiding performance you get from it. That would show how a longer focal length guider would perform. 

David

Great idea.  It would certainly highlight if the issue the OP is having is related to the choice of guidescope and camera.  But having said that, I'm now using the standard SW 9 x 50mm finderscope as a guidescope with an old mono QHY5 camera.  The focal length of the "guidescope" is 181mm and the QHY5 has 5.2um pixels, but I'm averaging 0.5" RMS guide error on both axis.  Whilst the OP has a 120mm focal length, his camera has a 3.2uf pixel size.    David, would there be much difference in what PHD2 sees ?  - Whilst my finderscoep is 50mm longer in focal length the pixels are 2um larger.

The guidescope / camera the OP uses seems to be a popular combination looking at both RVO and FLO websites.  There is even a review on FLO's site of someone using the same combination as the OP as far as main and guidescopes (although they don't state the mount they are using)

 

9 minutes ago, Wael Hassan said:

Thank you so much ... but i am still beginner and dont understand the meaning of X: 400 setting 😅 ?!

On PHD2 the X and Y axis of the graph is scalable by clicking selecting different values - click the button marked x400 and it will give you a list of other options - some increase the timeframe, others reduce it

Edited April 12, 2021 by malc-c

[Wael Hassan]

3 hours ago, malc-c said:

I would certainly be happy with a graph that was on the +/- 4 second scale... 

There is not a lot more to say as the other contributors have already covered things.  As for the PA issues, it could simply be that the guidesope is not 100% parallel to the RA axis.  But that is something you may never get, and you may end up making things worse.  I've covered how I aligned my guide scope with the main camera which got me close enough to 10" alignment.

At least you're getting results this time - well done

Thanks alot for all ur advices...you are a great help and support.... I am trying now to align axis by spirit level but it seems the RA is alityle bit away from the center...maybe the degree circle is not accurate

[davies07]

2 hours ago, Wael Hassan said:

Thanks alot for all ur advices...you are a great help and support.... I am trying now to align axis by spirit level but it seems the RA is alityle bit away from the center...maybe the degree circle is not accurate

 

Hi Wael,

I'm not sure what you are doing here. What are you trying to align with the spirit level? Are you adjusting the elevation of the RA axis to your latitude?

I can see you have a cover over the polar scope. Have you tried using that to polar-align the mount? It would be an interesting check. You should be able to get an app for your phone that will show you where Polaris should be relative to the polar scope graticule.

I thought this screen grab might be of interest:

This is a screen grab from my last evening out. I've labelled the controls on the left of the graph. As you can see, you can make the graph look smoother by changing the scales 🙂

The guiding performance figures are the metrics I normally monitor. As you can see here, my RA guiding is suffering because of the arrival of clouds. We get a lot of clouds.

In the list of items to be plotted under 'Settings' you will see 'Star mass' and 'Star SNR'. Star SNR (signal to noise ratio) is marked by the white line at the top of my plot and it is a measure of the clarity of the guide star. I find it a useful metric since it will reduce if there are clouds or other obstructions.

I take Malc's point about people having successful guiding solutions using your equipment and finder scopes, which also have short focal lengths. Indeed, I used to use a finder scope myself when I started. So, I remain puzzled by the noisy nature of your guiding results. I wonder if you are looking over a landscape that has been heated by the daytime Sun and is producing poor seeing in the night sky by thermals rising off the hot ground. If so, you would see a lot of star 'twinkle' which is an indication of poor 'seeing'.

Good luck on your next time out.

D

 

[Budgie1]

49 minutes ago, davies07 said:

I'm not sure what you are doing here. What are you trying to align with the spirit level? Are you adjusting the elevation of the RA axis to your latitude?

I questioned the alignment of the home position in the photo below because the weight bar looks angled to the West, when compared to the front leg of the tripod. I asked if this was a photo of the mount in it's Home Position. If it was, I suggested setting the home position again (video link provided which uses a spirit level for the process) and suggested marking the DEC & RA axis so the home position can be found without relying on the setting rings. 

18 hours ago, Wael Hassan said:

 

 

 

[malc-c]

Here's a suggestion:

1. Remove the telescope and guidescope from the mount - saves any possible damage occuring
2. Place the mount in the default home position with the weight bar vertically inline with the North facing tripod leg (don't worry about the setting circles shown in your earlier post)
3. Remove the covers off the polar scope (the scope that runs through the mount.)
4. connect the USB lead between the synscan unit and the PC.
5. Power up your computer 
6. Power up the mount.
7. Launch EQMOD and confirm the mount is shown as parked in the default home position.
8. Follow the video below on using EQMOD's polar alignment tool.  It should provide a basic position to start from.  The recital may be different to that show, but you'll get the gist

 

Fine tune the PA:

1. Having run through the EQMOD polar alignment tool park the mount back to the default home position.
2. Fit the main scope to the mount - leave the guidescope off the mount for now.
3. Fit the camera to the main scope, taking care not to move the mount
4. Open Sharpcap and run the polar alignment tool, ensuring you enter the details of the focal length of the main scope and not the details of the guidescope
5. Once  you have polar alignment as good as it gets (hopefully within the Good to Excellent rating) close Sharpcap

Guidescope:

1. Without moving the mount or main scope,  carefully reattach the guidescope  to the main scope and fit the camera to the guidescope
2. Connect the main camera to the main scope
3. In EQMOD set the slew rate to 4 and unpark the mount.
4. Set tracking to Sidereal
5. Using the NSEW buttons in EQMOD slew to a bright star that is clearly visible
6. Open Sharpcap  or whichever application controls the main camera and centre the star in the main camera's image
7. Change the selection to the guidecamera and centre the same star in the image form the guidecamera by adjusting the physical adjustment screws NOT USING THE NSEW BUTTONS IN EQMOD
8. Use EQMOD and select park to home.

Now providing the mount and scopes were not moved you should now have a mount that is polar aligned to the best of your ability, and the main and guide scopes are as close to parallel as you can get it

Guiding test:

1. With the mount Parked in the default home position close EQMOD
2. Launch PHD2 and select the option to connect to the guide camera and ASCOM mount - EQMOD should re- launch and PHD2 should open
3. Unpark the scope and select a target star that has at least 30 degrees declination and in the south and ideally close to the celestial equator.  I'm guessing that the celestial equator will be quite high up for you
4. Check the settings (ensure logging is enabled) in PHD2 match the guidescope and camera, set the exposure settings to 2 seconds and adjust the slider to give a pleasing image, and let PHD2 auto select a guide star

Post back with your findings.  To take screen captures click on PHD2 and then hold down the right CRTL key bottom right and press c at the same time.  Then open windows paint and paste the result into a new document.  Crop and save as before closing paint.  Upload your log files after doing this so we can see if anything has works, or if there are still issues.

Other than that I'm at a loss as I'm running out of suggestions.

[malc-c]

14 minutes ago, Budgie1 said:

I questioned the alignment of the home position in the photo below because the weight bar looks angled to the West, when compared to the front leg of the tripod. I asked if this was a photo of the mount in it's Home Position. If it was, I suggested setting the home position again (video link provided which uses a spirit level for the process) and suggested marking the DEC & RA axis so the home position can be found without relying on the setting rings. 

 

Martin, you did.

I'm sure the problem is that with three or four people all piling in with suggestions and recommendations the Wael simply missed that or went on to trying something else ?

Hopefully my last post, if followed, has covered your suggestion.  If not then he can always read through the tread again and see what he may have missed

[Budgie1]

1 hour ago, malc-c said:

Martin, you did.

I'm sure the problem is that with three or four people all piling in with suggestions and recommendations the Wael simply missed that or went on to trying something else ?

Hopefully my last post, if followed, has covered your suggestion.  If not then he can always read through the tread again and see what he may have missed

My second post about the home position wasn't a re-post of the idea, I was explaining to David (davies07) why Wael mentioned using a spirit level.  

Good idea to build it up slowly and make sure everything is aligned and set correctly. Hopefully Wael can get it sorted following your instructions.