PHD 2 issues

[alan potts]

I have been trying to get this going now for a while and am failing badly.

Now the first guide efforts were awful, all over the place, clearly not working correctly as it took about 5 seconds, if that to calibrate. Now whilst I would not say I understand this program I do at least have a better idea about than before Christmas, not that it seems to help. Now what is happening it the message "the star did not move enough"and a failed calibration, a good few times. Taking 40plus steps, even though steps are set at 15. The star tends to move no more than 4.0 seconds, or that could be pixels and this is after about 10 minutes.

I am using a SW AZ EQ 6 which seems to guide fairly well at 90 seconds or so. The camera is a Brightstar Mammut L429 colour with 8.6mu pixels. The guide scope is a Baader Vario 60mm finder with a F/L or 250mm at F4. I was using ST4 connections to mount from camera and using on camera settings. I have no trouble seeing stars through it on screen.

The laptop can clearly see the camera and mount and though I have tried PHD 1 this will not see the driver for the camera even though it is there in the menu.

Can anyone throw some light, please keep it simple as I am easily confused with this stuff until I get it in my head, I am sure I am not on my own there, for what it's worth I feel the camera/finder combo is no good, but then I know nothing. I have read plenty on the site and had help from fellow Mods but they all run PHD 1.

Alan

[kens]

Hi Alan

Can you post the guide log located under Documents\PHD2 as this will help the analysis

To explain how calibration works: PHD2 sends guide pulses of the specified length to the mount. The first pulses (should) move the mount west. PHD2 will keep sending pulses to the mount until it has moved west by 25 pixels. It will send up to 50 pulses to do this after which it gives the error message you have seen.

Did you set up your camera and mount using the profile wizard? If not,  try that.

Otherwise, try the Star Cross Test on the Tools menu. This will check if the mount is responding properly to guide pulses.

[alan potts]

23 minutes ago, kens said:

Hi Alan

Can you post the guide log located under Documents\PHD2 as this will help the analysis

To explain how calibration works: PHD2 sends guide pulses of the specified length to the mount. The first pulses (should) move the mount west. PHD2 will keep sending pulses to the mount until it has moved west by 25 pixels. It will send up to 50 pulses to do this after which it gives the error message you have seen.

Did you set up your camera and mount using the profile wizard? If not,  try that.

Otherwise, try the Star Cross Test on the Tools menu. This will check if the mount is responding properly to guide pulses.

Cheers Ken, I will look at this to see if I can, it's on another laptop, yes it sent 50 pulses I guess but only moved it just over 4 pixels, nowhere near 25. Yes I did use the wizard and have tried many different settings that seem to do very little as far as I can see, you could well be right the mount is not receiving correct information, it is set at 1.0 for guide speed, .5 is default.

[vlaiv]

I'll try to keep it simple, but there are couple of concepts that you have to understand to be able to diagnose what is happening.

With Baader Vario 60mm guide scope and your guide camera, guiding resolution is 7.1"/pixel. This is not so good guide resolution - too coarse to do precise guiding - if we assume 1/16 guide accuracy (don't worry about this number, but it is estimated that in best case scenario computer is able to give guide star position with one sixteenth of guide resolution) - your guide precision is ~ 0.45" - this means that computer won't be able to tell that there is change in guide star position if mount moves less than or close to this value.

Next thing that you should know is what is your guide rate, and what guide pulse duration you are using to calibrate. Guide rate is expressed in fraction of sidereal rate. So you might be guiding at 0.25 or 0.5 or 0.75 or something like that of sidereal rate. Sidereal rate is ~15"/second, so if you have your calibration pulse set to let's say 100ms - you would expect your guide star to move 0.75" if your guide speed is 0.5  and only 0.375" if your guide speed is 0.25 - and this is at declination 0 - you should calibrate close to declination 0.

This translates into less than 2 pixels of motion (well under 1px of motion for guide speed of 0.25), and that is under best conditions for centroid algorithm (often not so).

PHD2 can get confused if it is expecting to see the star move, but in fact it is not moving as expected.

Things that I would suggest you check and set in PHD2:

1. Make sure you entered focal length and camera pixel size correctly.

2. Make sure you use dark frames - this will avoid problems with hot pixels, on this resolution hot pixel can be easily mistaken for a star - and you will get complaint about guide star not moving.

3. Calibrate near or at declination 0

4. Based on your guide speed, calculate your calibration pulse to be such that it moves guide star enough - at least 5 pixels in each step. For guide speed of 0.25 that value should be something like 600ms, but you can calculate it from above mentioned sidereal rate, guide speed and guider resolution.

 

[vlaiv]

To add some more info:

https://openphdguiding.org/man-dev/Advanced_settings.htm#Guiding_Tab

There is dialog to help you calculate guide step, just enter few parameters (focal length, pixel size, guide rate and declination) and it will give you good value for calibration step size.

[LightBucket]

The calibration step size should be set according to your scope size, so if you are using a step of 15, then your scope must be about 3M wide....lol, on my 8” I used a calibration step of 750 and on an 80mm about 250. That’s the reason you are getting the warning that the guide star did not move enough, check the help section on PhD it should give you an idea of calibration step sizes...

the more focal length you have, the smaller the step size as it is much more magnified, and the smaller the scope the higher the step size, as it needs to move more to be seen by the guide camera...

 

[alan potts]

2 hours ago, vlaiv said:

I'll try to keep it simple, but there are couple of concepts that you have to understand to be able to diagnose what is happening.

With Baader Vario 60mm guide scope and your guide camera, guiding resolution is 7.1"/pixel. This is not so good guide resolution - too coarse to do precise guiding - if we assume 1/16 guide accuracy (don't worry about this number, but it is estimated that in best case scenario computer is able to give guide star position with one sixteenth of guide resolution) - your guide precision is ~ 0.45" - this means that computer won't be able to tell that there is change in guide star position if mount moves less than or close to this value.

Next thing that you should know is what is your guide rate, and what guide pulse duration you are using to calibrate. Guide rate is expressed in fraction of sidereal rate. So you might be guiding at 0.25 or 0.5 or 0.75 or something like that of sidereal rate. Sidereal rate is ~15"/second, so if you have your calibration pulse set to let's say 100ms - you would expect your guide star to move 0.75" if your guide speed is 0.5  and only 0.375" if your guide speed is 0.25 - and this is at declination 0 - you should calibrate close to declination 0.

This translates into less than 2 pixels of motion (well under 1px of motion for guide speed of 0.25), and that is under best conditions for centroid algorithm (often not so).

PHD2 can get confused if it is expecting to see the star move, but in fact it is not moving as expected.

Things that I would suggest you check and set in PHD2:

1. Make sure you entered focal length and camera pixel size correctly.

2. Make sure you use dark frames - this will avoid problems with hot pixels, on this resolution hot pixel can be easily mistaken for a star - and you will get complaint about guide star not moving.

3. Calibrate near or at declination 0

4. Based on your guide speed, calculate your calibration pulse to be such that it moves guide star enough - at least 5 pixels in each step. For guide speed of 0.25 that value should be something like 600ms, but you can calculate it from above mentioned sidereal rate, guide speed and guider resolution.

 

Need to read this a few times to understand it.

1 F/L is entered correct. pixel size I set for detect, it was 8.6mu.

2 The camera is cooled and there are no hot pixels, however at no point in te 5 attempts has Darks come into the step by step set up, I have tried everything to open Darks and failed.

3. I have a 420mm F6 ED scope I could use, would that be better.

4 how do I set the Pulse, I do not understand, the sidereal rate of what, the scope is set at 1.0 the lowest setting I believe is 0.5, guide speed and resolution I have no idea what these are.

Thanks for taking the time to reply, this is meant to be a easy to use program. I feel my gear is not idea as i said, I will have to get better guide scopes and camera if I carry on.

Alan

[alan potts]

2 hours ago, LightBucket said:

The calibration step size should be set according to your scope size, so if you are using a step of 15, then your scope must be about 3M wide....lol, on my 8” I used a calibration step of 750 and on an 80mm about 250. That’s the reason you are getting the warning that the guide star did not move enough, check the help section on PhD it should give you an idea of calibration step sizes...

the more focal length you have, the smaller the step size as it is much more magnified, and the smaller the scope the higher the step size, as it needs to move more to be seen by the guide camera...

 

This step number comes up in another section and I felt this was the number of steps in the Cal process. The number I believe you are refering to was done by auto detect based on scopeF/L at 250mm, the result was set at 1150, I believe, this did nothing. I still am getting nice results from just the mount at 90secs or so, but I will need to nail guiding before I spend on a new CCD, which may well be a hi res one Atik 490 or so.

[LightBucket]

Just now, alan potts said:

This step number comes up in another section and I felt this was the number of steps in the Cal process. The number I believe you are refering to was done by auto detect based on scopeF/L at 250mm, the result was set at 1150, I believe, this did nothing. I still am getting nice results from just the mount at 90secs or so, but I will need to nail guiding before I spend on a new CCD, which may well be a hi res one Atik 490 or so.

Ah ok, my mistake....

[vlaiv]

8 minutes ago, alan potts said:

Need to read this a few times to understand it.

1 F/L is entered correct. pixel size I set for detect, it was 8.6mu.

2 The camera is cooled and there are no hot pixels, however at no point in te 5 attempts has Darks come into the step by step set up, I have tried everything to open Darks and failed.

3. I have a 420mm F6 ED scope I could use, would that be better.

4 how do I set the Pulse, I do not understand, the sidereal rate of what, the scope is set at 1.0 the lowest setting I believe is 0.5, guide speed and resolution I have no idea what these are.

Thanks for taking the time to reply, this is meant to be a easy to use program. I feel my gear is not idea as i said, I will have to get better guide scopes and camera if I carry on.

Alan

Well, you can use 420mm F/6 ED scope for guiding, and it would certainly get you better guide precision, but for time being, just focus on getting guiding to work, later on you can improve it if there is need for it - it depends on your actual imaging resolution.

Sidereal rate is just reference "speed" at which normally mount tracks - it tracks the same speed that earth is revolving around its axis. This speed is roughly 360 degrees in a day, or 15 degrees an hour - or in the end you end up with 15 arc seconds per second. So when you choose guide rate of x1.0 movement of your mount relative to guide star is sidereal_rate * 1.0 * pulse_duration. If you choose guide rate of x0.5 than for same pulse duration mount will move only half of that. This is what 1.0 and 0.5 stand for - coefficient of sidereal rate when guiding. Not something you need to know, but it does explain how these values are calculated. There is "automatic" calculation of this in PHD2.

On a side note, you might want to guide with x0.5, rather than x1.0. Rate of x1.0 is pretty aggressive, and I would recommend it for mounts with best mechanics.

Now there are two types of pulses that PHD2 uses - calibration pulse and guide pulse. Both mean same thing but are slightly different in what they do. Guide pulse is of variable duration, so PHD2 calculates what correction needs to be made and issues pulse of a needed duration for mount to correct its position. It depends on guide speed and by how much mount needs to move to get to true position. Guide pulse is not something you need to control or worry about now.

Calibration pulse is always of the same duration - it helps PHD2 to see how mount behaves, which way the guide camera is oriented and to get statistics that it needs to correctly calculate guide pulses later on when it starts guiding.

In order for PHD2 to successfully calibrate, calibration pulse must be long enough to actually move the mount in such a way that it is detected on guide camera. Small movement might not be enough to be caught on camera if camera has large pixels, and guide scope FL is small. Small calibration pulse duration can also lead to "Star did not move" problem.

You enter calibration pulse duration in settings in PHD2. Here is screen shot to help you:

So you need to enter meaningful number there, and I explained in first post how to calculate it. But you don't need to calculate it manually, there is "Calculate ..." button next to it.

You just need to enter your values in it. FL will be 250mm, Pixel size will be 8.6um, guide speed will be either 1.00 if you keep using x1.0 guide speed, or 0.5 if you decide to use lower value (which I recommend you do).

Calibration steps should be in range of 10-20, I use 16 for example, the more you use, the more precise calibration will be.

You also need to put in Calibration declination - this being declination of a star you use to calibrate with. If you use EQMOD, or your mount driver can read this information it should be already populated with correct value. If not, just select a star somewhere near DEC 0 and enter DEC value of that star.

It should then calculate calibration step, and if everything is ok, it should also write out 7.1 in arc-sec/px box. If you press ok it should write calculated step size into previous dialog, and everything should be set to go.

 

[kens]

A thought just came to my mind. You need to clibrate well away from teh pole and preferably near the celestial equator (declination 0 degrees) and close to the meridian.

If you try to calibrate near the pole you wont get enough movement. Now if you use ASCOM guiding the mount tells PHD2 what its declination is and you would get a warning near the pole. With ST4 and probably with PHD1 there is no such warning.

On reason I always ask for the guide log is that all the information you've been asked for is in the PHD2 log. The PHD1 log however is quite sparse.

[alan potts]

24 minutes ago, kens said:

A thought just came to my mind. You need to clibrate well away from teh pole and preferably near the celestial equator (declination 0 degrees) and close to the meridian.

If you try to calibrate near the pole you wont get enough movement. Now if you use ASCOM guiding the mount tells PHD2 what its declination is and you would get a warning near the pole. With ST4 and probably with PHD1 there is no such warning.

On reason I always ask for the guide log is that all the information you've been asked for is in the PHD2 log. The PHD1 log however is quite sparse.

Ken,

The is absolutely nothing in PHD 2 Log files,it  is just an empty folder. I was calibatrating on M45 as it is easy to see with the scope and there was no chance of there not being a star around. I am using ST4 on camera, the camera is cooled BTW. I feel something is very wrong here, I can see myself guiding with the APM 115mm and banging the Canon 40D on the Baader Vario which I have a very low opinon of. 

Thanks for taking the time to try and help, sadly I have no one out here that could show me anything, maybe why I have always been a visual man.

Alan 

[alan potts]

40 minutes ago, vlaiv said:

Well, you can use 420mm F/6 ED scope for guiding, and it would certainly get you better guide precision, but for time being, just focus on getting guiding to work, later on you can improve it if there is need for it - it depends on your actual imaging resolution.

Sidereal rate is just reference "speed" at which normally mount tracks - it tracks the same speed that earth is revolving around its axis. This speed is roughly 360 degrees in a day, or 15 degrees an hour - or in the end you end up with 15 arc seconds per second. So when you choose guide rate of x1.0 movement of your mount relative to guide star is sidereal_rate * 1.0 * pulse_duration. If you choose guide rate of x0.5 than for same pulse duration mount will move only half of that. This is what 1.0 and 0.5 stand for - coefficient of sidereal rate when guiding. Not something you need to know, but it does explain how these values are calculated. There is "automatic" calculation of this in PHD2.

On a side note, you might want to guide with x0.5, rather than x1.0. Rate of x1.0 is pretty aggressive, and I would recommend it for mounts with best mechanics.

Now there are two types of pulses that PHD2 uses - calibration pulse and guide pulse. Both mean same thing but are slightly different in what they do. Guide pulse is of variable duration, so PHD2 calculates what correction needs to be made and issues pulse of a needed duration for mount to correct its position. It depends on guide speed and by how much mount needs to move to get to true position. Guide pulse is not something you need to control or worry about now.

Calibration pulse is always of the same duration - it helps PHD2 to see how mount behaves, which way the guide camera is oriented and to get statistics that it needs to correctly calculate guide pulses later on when it starts guiding.

In order for PHD2 to successfully calibrate, calibration pulse must be long enough to actually move the mount in such a way that it is detected on guide camera. Small movement might not be enough to be caught on camera if camera has large pixels, and guide scope FL is small. Small calibration pulse duration can also lead to "Star did not move" problem.

You enter calibration pulse duration in settings in PHD2. Here is screen shot to help you:

So you need to enter meaningful number there, and I explained in first post how to calculate it. But you don't need to calculate it manually, there is "Calculate ..." button next to it.

You just need to enter your values in it. FL will be 250mm, Pixel size will be 8.6um, guide speed will be either 1.00 if you keep using x1.0 guide speed, or 0.5 if you decide to use lower value (which I recommend you do).

Calibration steps should be in range of 10-20, I use 16 for example, the more you use, the more precise calibration will be.

You also need to put in Calibration declination - this being declination of a star you use to calibrate with. If you use EQMOD, or your mount driver can read this information it should be already populated with correct value. If not, just select a star somewhere near DEC 0 and enter DEC value of that star.

It should then calculate calibration step, and if everything is ok, it should also write out 7.1 in arc-sec/px box. If you press ok it should write calculated step size into previous dialog, and everything should be set to go.

 

Everything you have pointed out here which clearly took some time, thank you for that has been done and correctly, as far as I can see.

There are 8 boxes with info in in this section on calibration. It reads 1 - F/L 250mm, 2 - Pix micons 8.60, 3 - Binning = 1, 4 - Guide speed 1.00, 5 - Cal steps 15, 6 Cal Dec Degrees = 0, 7, Computed value = 7.10 (not bold type) and 8 Cal step m/s 1100.

I feel something is wrong somewhere. I am using ST4 on camera .

Alan 

[kens]

11 minutes ago, alan potts said:

Ken,

The is absolutely nothing in PHD 2 Log files,it  is just an empty folder. I was calibatrating on M45 as it is easy to see with the scope and there was no chance of there not being a star around. I am using ST4 on camera, the camera is cooled BTW. I feel something is very wrong here, I can see myself guiding with the APM 115mm and banging the Canon 40D on the Baader Vario which I have a very low opinon of. 

Thanks for taking the time to try and help, sadly I have no one out here that could show me anything, maybe why I have always been a visual man.

Alan 

What version of PHD2 are you using? The logs have been produced automatically since about 2.4 (from memory) but prior to that they needed to be explicitly enabled.

The latest version (2.6.4) is at https://openphdguiding.org/downloads/ If you install that it wil be easier to get you going. 

If you were calibrating at M45 then that is near enough to the celestial equator. You can see stars so that is also good and shows the camera/finder combo is ok. I assume you selected a guide star on the display as indicated by a green square around the star. You can also enable a star profile (View > Star Profile) to see the selected star close up.

One test you can do in daylight it to point the scope at a distant object. Start PHD2 and connect the camera and mount as usual. Loop the display to see the object on the screen. Select View>Display Bullseye  to overlay a bullseye on the display. Then use the Tools>Manual Guide option. Set Guide Pulse Duration to 5000 (the largets allowed value). The click any of the direction buttons and see if the display moves. A few clicks may be necessary to discern movement. The bullseye helps to see small movements.

If that all works then calibration should be possible with the right parameters. If not, there could be a problem somewhere between the camera and mount (inclusive)

[vlaiv]

1 hour ago, alan potts said:

Everything you have pointed out here which clearly took some time, thank you for that has been done and correctly, as far as I can see.

There are 8 boxes with info in in this section on calibration. It reads 1 - F/L 250mm, 2 - Pix micons 8.60, 3 - Binning = 1, 4 - Guide speed 1.00, 5 - Cal steps 15, 6 Cal Dec Degrees = 0, 7, Computed value = 7.10 (not bold type) and 8 Cal step m/s 1100.

I feel something is wrong somewhere. I am using ST4 on camera .

Alan 

Ok, so only other thing that might cause trouble with this procedure, that I can think of is, since you are using ST4 guiding is that you are calibrating on a star that is high in declination, but DEC value for calibration is left at 0.

What star do you calibrate on?

[alan potts]

14 minutes ago, vlaiv said:

Ok, so only other thing that might cause trouble with this procedure, that I can think of is, since you are using ST4 guiding is that you are calibrating on a star that is high in declination, but DEC value for calibration is left at 0.

What star do you calibrate on?

I forgot to tell you I was on M45 every time in 4 times out, I have tried other places like Alnitak and Orions sword, picked because I could see any amount of stars, I don't think M45 is a high Dec or the others. I still feel something isn't working as it should, as to what this is I may just throw in the towel, by accident I have a poor selection of gear.

Alan

[vlaiv]

Yes, M45 is at DEC 25 or so, so that should not be a problem ...

Only other thing that I would suggest is to try using EQMOD as ASCOM driver and give it a go over ST4. Other than that, it really might be some sort of a problem with gear.

[alan potts]

1 hour ago, kens said:

What version of PHD2 are you using? The logs have been produced automatically since about 2.4 (from memory) but prior to that they needed to be explicitly enabled.

The latest version (2.6.4) is at https://openphdguiding.org/downloads/ If you install that it wil be easier to get you going. 

If you were calibrating at M45 then that is near enough to the celestial equator. You can see stars so that is also good and shows the camera/finder combo is ok. I assume you selected a guide star on the display as indicated by a green square around the star. You can also enable a star profile (View > Star Profile) to see the selected star close up.

One test you can do in daylight it to point the scope at a distant object. Start PHD2 and connect the camera and mount as usual. Loop the display to see the object on the screen. Select View>Display Bullseye  to overlay a bullseye on the display. Then use the Tools>Manual Guide option. Set Guide Pulse Duration to 5000 (the largets allowed value). The click any of the direction buttons and see if the display moves. A few clicks may be necessary to discern movement. The bullseye helps to see small movements.

If that all works then calibration should be possible with the right parameters. If not, there could be a problem somewhere between the camera and mount (inclusive)

I am using the PHD2 and I downloaded it only a few weeks back, it is the version you stated. I also did everything you say, auto select guide satr and manual, I will try as you suggest.

I am putting a few bob on connections betweem camera and mount. The ST4 connector on both camera and mount is a 4 cable connector but it uses a 6 wire wide plastic socket, my cable is only a 4 wires wide plug but this came with the camera (a poor choice in my view) getting an exact fit has not been easy though I check it for being in the right place every time. I don't know the correct terms for these connectors but I am sure you have seen they are normally 4, 6 and 8, 8 being the telephone type. I just have to keep pluging away, it is a shame as I am enjoying the AP side of things, it's just the software I can't stand, most find Photoshop hard work, it's a good job I don't.

 

[alan potts]

8 minutes ago, vlaiv said:

Yes, M45 is at DEC 25 or so, so that should not be a problem ...

Only other thing that I would suggest is to try using EQMOD as ASCOM driver and give it a go over ST4. Other than that, it really might be some sort of a problem with gear.

Am i right im believing then doing EQMOD the computer drives the mount and not the camera. I am not happy with the cable that came with the camera for ST4 but really I didn'tknow another way. So I will require ST4 to USB, would that be right and leave off the camera to mount connection?

Alan

[vlaiv]

3 minutes ago, alan potts said:

Am i right im believing then doing EQMOD the computer drives the mount and not the camera. I am not happy with the cable that came with the camera for ST4 but really I didn'tknow another way. So I will require ST4 to USB, would that be right and leave off the camera to mount connection?

Alan

With EQMod, I have following arrangement when guiding:

- EQMod cable from computer goes into mount instead of hand controller. I'm not sure about AZ6, if it has different connection, that is something you need to research, but for HEQ5 it just goes in place of hand controller.

- USB2.0 cable from guide camera to computer.

So no need for ST4 cable between camera and mount. EQMod does goto and sends guide commands to mount. On HEQ5 there is also no PPEC so I use PEC in EQMod.

[kirkster501]

Unless you get the Calibration step size right, you are peeing in the wind.  

Calibration step size  is related to your focal length.  You must enter this in the brain icon.  Use pulse guiding and forget the ST4 cable.  Pulse guiding works on the same cable from the computer that drives the mount.  There is no need for additional cables.

When I had an EQ6 I could guide it perfectly.

[alan potts]

On 09/01/2018 at 21:59, kirkster501 said:

Unless you get the Calibration step size right, you are peeing in the wind.  

Calibration step size  is related to your focal length.  You must enter this in the brain icon.  Use pulse guiding and forget the ST4 cable.  Pulse guiding works on the same cable from the computer that drives the mount.  There is no need for additional cables.

When I had an EQ6 I could guide it perfectly.

OK I hear what you say and peeing joke it fairly apt this end at the moment as I am having troubles in that area. That aside the calibration steps were calulated by the program in the focal length and pixel size section at 1100ms. How does one set up this Pulse guiding and what do you drive it with software wise, cables etc. I am not very good at understanding computer software, I mean PHD is meant to be easy to use, not for me I do assure you. I am really wondering if there is something wrong with a part of the setup

[alexbb]

Hi Alan,

I didn't read anywhere you drive your mount via ASCOM/EQDIR so I suppose you control it with the handset.

If this is the case and if you still want to control it with the handset, you can guide through the ST4 cable. I agree that pulse guiding could work better, but neither through ST4 is bad. I guide my AZ-EQ5 and EQ5 through ST4 and I had no issues since the first time I set them up. The issues that I think you might encounter are either the guiding speed configured on the handset does not correspond to the value set in PHD, either the ST4 cable is a bad one, either both.

With PHD you should be able to slightly move the mount manually in the Manual Dithering dialog. If it doesn't, then the communication between the camera and the mount is not done. I would blame the cable for this. The camera or the mount could have problems themselves, but I doubt this.

Btw, I think you should also be able to test this during the day. Just disable the tracking on the handset and try to move the mount from PHD with guiding commands. Not sure though.

HTH,

Alex

[alan potts]

28 minutes ago, moise212 said:

Hi Alan,

I didn't read anywhere you drive your mount via ASCOM/EQDIR so I suppose you control it with the handset.

If this is the case and if you still want to control it with the handset, you can guide through the ST4 cable. I agree that pulse guiding could work better, but neither through ST4 is bad. I guide my AZ-EQ5 and EQ5 through ST4 and I had no issues since the first time I set them up. The issues that I think you might encounter are either the guiding speed configured on the handset does not correspond to the value set in PHD, either the ST4 cable is a bad one, either both.

With PHD you should be able to slightly move the mount manually in the Manual Dithering dialog. If it doesn't, then the communication between the camera and the mount is not done. I would blame the cable for this. The camera or the mount could have problems themselves, but I doubt this.

Btw, I think you should also be able to test this during the day. Just disable the tracking on the handset and try to move the mount from PHD with guiding commands. Not sure though.

HTH,

Alex

Not that I understand this program very well, though I do at least now know what some of you are talking about, the more I look at this the more I feel it is a combination of bad backlash or poor cable. You probable know the correct names for the various fittings of these type of clip in ST4 cables, I don't. They tend to be 8 wires wide, 6 wires wide or 4. Now the female socket of the camera and mount is 6 wide but only carries 4 wires. The cable that came with the camera is a 4 wire wide fitting with 4 cables, this though will go into a 6 wire socket. I fee there may well not be a clean contact.  I also have the issue of a 250mm Vario guide scope and a 8.6mu pixel camera, far from idea. I think I have been making life hard for myself.

But I guess you know the score, wanting to make a start in imaging and trying to make use of what you have until such time you see you like it or drop it. I want to explore all I can without buying new, I have my eyes on a 490ex but that's useless unless I can guide first, I am finding it a bit of a drag if i'm honest, dark forces at play here I am sure.

alan

[newbie alert]

Hi Alan,you will get there so dont get to disheartened..guiding at 10 mins plus is all worth the effort in the end..ive not calibrated at declination  0 so I need to recalibrate..new scope and mount so it all needs re doing..skies have been awful lately so not had a chance..clouded up before having a chance to polar align..

Hopefully tonight if the cloud gods stay away