My query about PHD2

[Pankaj]

Hi. With monsoons now nearing an end here in India and winters to start soon, I am looking forward for a great imaging session during October and November. 

I had been imaging unguided for a long time now, but just entering the phase of guided AP. Going by the valuable suggestions by members on this forum, I had been purchasing the equipment since last 3 months and practicing on PHD2 too.

My two queries are related to PHD2.

1. While practicing with an artificial star indoors, I realized that the calibration process gets completed successfully only if the star moves 'enough' in RA and DEC. If it does not move then a message pops up saying 'star did not move enough in RA/DEC, calibration failed'. Does this mean that the better the polar alignment of the mount, the more time would be taken by PHD2 for calibration?

2. During practicing on simulation mode, the CAL does not turn fully green. Instead it turns yellow. What is the meaning of this and how would it impact guiding if this happens in real time AP session. 

[alacant]

50 minutes ago, Pankaj said:

the polar alignment of the mount, the more time would be taken by PHD2 for calibration?

Calibration takes a minute or so, so I wouldn't worry about it. The polar alignment doesn't need to be exact. Get it somewhere near the pole and come back to it later when you have calibrated and started guiding. Remember that you cannot practise calibration using a fixed star but you can with the PHD2 simulators. You'll find however that once you're out under the stars, things will be very different;)

50 minutes ago, Pankaj said:

Instead it turns yellow. What is the meaning of this and how would it impact guiding

It means that PHD2 does not have a mount calibration to work with. The impact would be that you would not be able to guide; as soon as you hit guide, PHD2 will attempt a calibration.

Glad to hear that the rain has stopped and so good luck with the ap:)

[Freddie]

53 minutes ago, alacant said:

Calibration takes a minute or so, so I wouldn't worry about it. The polar alignment doesn't need to be exact. Get it somewhere near the pole and come back to it later when you have calibrated and started guiding. Remember that you cannot practise calibration using a fixed star but you can with the PHD2 simulators. You'll find however that once you're out under the stars, things will be very different;)

It means that PHD2 does not have a mount calibration to work with. The impact would be that you would not be able to guide; as soon as you hit guide, PHD2 will attempt a calibration.

Glad to hear that the rain has stopped and so good luck with the ap:)

That's not correct.

When it turns yellow it means it has completed calibration successfully, but does not have pointing information for the mount i.e. it is only being controlled by the hand controller and not via a computer prog. such as CdC. Therefore the fact that it is yellow and not green will have no impact on guiding, you will just need to recalibrate if you move to a different target in a different location in the sky.

[alacant]

4 minutes ago, Freddie said:

That's not correct.

You've quoted everything as not correct. Is that correct?

[Freddie]

No, I was refering only to the part I went on to explain. Though in addition, you can practice calibration on a fixed star as the calibration will still move the mount and the fact that the star itself isn't moving doesn't really matter. You can't practice guiding on a fixed star.

[Pankaj]

Hi Aalacant, Freddie

Regarding point number 1 - Got your point. I would get under the stars very soon.

With regards to CAL turning yellow and not Green - I am connecting my guide camera directly to the mount's ST4 guide port. And my guide camera is connected to my computer through USB. So I guess, PHD2 is sending correction signals to the mount through the guide camera. Hence, in this case in the PHD2 hardware selection, I am selecting ''on camera'' for the Mount drop down list. I also control the mount through the synscan handset and do not use softwares like stellarium etc. Guess this could be the reason why CAL is turning yellow and not Green. I too read somewhere that guiding would still be effective in this case. But thought of taking advise on this forum as till date the members of this forum have always provided absolutely perfect advise to me.

[Pankaj]

Hi. Finally got under the stars today to check out how guiding would have performed. Just to brief - My Datyson T7 guide cam was connected with PC through its USB. My NEQ6 was connected with Datyson T7 through the guide port ST4.

In the PHD2, my equipment settings were : Camera - ZWO ASI  ;  Mount - On Camera

Started with 5 minute subs on my imaging camera Canon 1200D. 

PHD2 Guiding - attached is a screenshot. After an auto star select and calibration , PHD2 started showing ''Guiding'' automatically on its own. It kept the star in the cross in the green cross hairs for about 3min30sec. Thereafter the star moved (as shown in the pic) away from the cross hairs. But PHD2 kept on showing ''Guiding'' (as shown the pic below). It kept on showing ''Guiding'' while the star moved away from cross hairs. Apprehending something amiss, I ended the imaging session after full five minutes. When I checked the pic taken by Canon 1200D, I found significant star trails. Was a bit shocked to see star trails despite the fact that PHD2 kept on showing ''Guiding'' throughout this  minutes. To test further, I decided to see if indeed PHD2 was guiding or not. For doing so, I slewed the mount. Immediately on doing so, PHD2 started showing ''star lost''. So, I guess it was guiding all this time....but the why the star trails ???? What is it I am doing wrong?? Please help.....attached below is a pic of my computer screen..
 

[Pankaj]

Kindly note in above pic - CAL is yellow...no green...
 

 

[kens]

Can you attach the Guide log from that session? Under the help menu select Open Log Folder to find the log. Screen shots are no good for diagnosing problems.

[Pankaj]

Hi Kens,

Please find attached the log.

I would also like to add that I tried to shoot M45 with guiding which was perfect because I could take 5 minute exposure shots without any trail. But that was the only success I had as any attempt other than that was in vain.

Request help please please please.......

PHD2_GuideLog_2018-09-29_230858.txt

[kens]

There is a serious issue with your calibration. Instead of moving West, East, North, South it goes West, South, East, North

Its possible your ST4 cable is wired incorrectly or shorting.

Next step is to run the star cross test from the Tools menu.

[Pankaj]

Hi. I just checked the log again.  Upon completion of Calibration process and before the mount started Guiding at 23:14:35 hours, the mount had completed calibration by moving  WEST - EAST - BACKLASH - NORTH - SOUTH. 

Later in the night, I tried doing a star cross test too. Attached is the image that appeared on my main imaging camera screen. 

Having said the above, if there's an issue with the cable and if PHD2 was not properly guiding, the why on the screen it was showing as ''Guiding'' if the star was NOT getting held by it ?

[kens]

During calibration PHD2 moves the mount West, East, North then South. But in your case the mount did not move as commanded. You also ended up with an Orthogonality error after the calibration. 

The star cross test confirms that the mount is not moving according to the guide commands. As its name suggests the star cross test should draw a cross but instead you get an S shape.

I think your ST4 cable has the wrong pin connections.

[Pankaj]

Got it Kens. So the other option for me to connect the mount directly with my laptop for guiding. Should I connect the Auto Guiding port on the mount directly with the laptop? In such a case the guide cam will give live feed to PHD2 and the correction commands from PHD2 will be sent to the mount directly.  

 

[kens]

Connecting directly from computer to mount has its advantages. I'm assuming you are using the NEQ6 mount? If so and if you have a USB to serial adapter you need to plug that into the hand controller and set the hand controller to PC-Direct mode. In PHD2 select EQMOD ASCOM HEQ5/6 as the mount. To connect directly from computer to mount you need a EQDIR type cable like the Shoestring USBEQ6 http://www.store.shoestringastronomy.com/products_eq.htm and it plugs in where the hand controller goes.

Do NOT try to plug  a regular USB serial cable into the mount or you could damage the mount. Even though the plug looks the same the voltages are higher.

[Pankaj]

Yes I have an NEQ6 and also a USB to Serial adapter to connect to the laptop. In such a case, will I be using the hand controller to operate the mount or will I have to use another software to do this...like Stellarium? I would like to operate the mount with handC as it will be too many softwares to handle. So in such a case, I do polar alignment and 2 star alignment through handC. Then slew on to a target using goto. The mount will start tracking immediately as it settles on the target. NOW at this stage do I have to put the handC on PC Direct Mode and let the mount take guiding commands from the computer? Oh man....I am so confused.... 

[alacant]

3 hours ago, Pankaj said:

will I have to use another software to do this

Hi. Yes. You've already got the computer connected so you'd make life easier if you used pulse guiding rather than st4 . These work well; connect it directly from the mount to the computer and lose the st4 cable (or use a hub near the telescope with a single usb cable back to the computer). Stellarium is ok, when I used windows I prefered cartes du ciel.

HTH

[Pankaj]

Thanks for the reply Alacant. 

I use the sysnscan handset for polar alignment and 2 star alignment. Once that gets complete, do I switch over to Stellarium by selecting PC Direct on the handset ? Or is there a different way.

[Pankaj]

Is there a complete tutorial which can explain the entire process in one go. Tried searching the web, but couldn’t find any. There were basic questions like -

how to sync stellarium with pointing info of the mount after we switch from handset to stellarium by using PC Direct option on the handset.

On certain threads there’s talk about using stellarium scope and not Stellarium? 

Stellarium asks for scope details not mount details. Or do I have to fill mount details in this column

After choosing a target for imaging and slewing the mount to it, I think the scope will automatically track. Thereafter I will calibrate PHD. Once calibration gets completed and guiding starts, will the guide commands automatically get transmitted to the mount through the usb serial adaptor, or do I have to synk PHD too, to ensure it has the pointing information about the mount?

[kens]

I guess it is possible to switch mid-stream from using the hand controller to computer control but I don't know of anyone who persists with it.

Sounds like you already have ASCOM and EQMOD installed but if not install them.

Install StellariumScope. http://welshdragoncomputing.ca/x/index.php/home/stellariumscope/download-stellariumscope That allows you to use Stellarium alongside other applications like PHD2 and sync with the mount coordinates. You'll need to enable the Telescope Control plug-in.

Use EQMOD to move your mount around. If you want you could try using a Game controller with it. You could also try using Stellarium to do a goto by selecting your target and then clicking Ctrl-1 

There are some tutorials online about syncing the scope but I've always plate-solved instead so can't help you there. In due course you will probably start plate-solving so start reading up about that. Another barrel of fun

For polar alignment you could try the tools in PHD2. Which one you use depends on whether you can see the celestial pole or not.

 

 

 

[Pankaj]

Thanks a ton for the support. I have just ordered a ST4 guide cable from FLO. Will replace it with the existing one which seems defective as suggested by you. If this works, then probably for the time being i’ll Stick to st4 guiding. If not, then I guess i’ll come to guiding using the laptop. Just finished ordering to FLO. Wish me luck ?