QHY PoleMaster

[StuartJPP]

6 hours ago, themos said:

I don't see how the clutches could have anything to do with it...either your RA axis is secure or it's wobbly in which case you're going to have problems anyway, no matter how well you think you aligned it.

I can only assume that if you release the clutches and then lock them again at another part of the shaft there could be a little bit of discrepancy between the two points, doesn't mean it is wobbly just that it isn't uniform. To get the quoted 30 arcseconds accuracy even being off by 1 pixel will prevent that.

 

10 hours ago, themos said:

Hello,

How is this PoleMaster different from the method I described on SGL last year? 

I was one of the users of your alignment method and I really appreciate what you did in fact I was in the process of writing some software based on your method to do exactly what PoleMaster is doing, that is...using live video instead of snapshots and solving a simple template at a fixed focal length rather than plate solving...however PoleMaster came along...

Of course my software would have been bespoke to my camera and focal length so not quite as flexible as your solution but easier/quicker for me to use.

[themos]

I always wanted other people to take the idea and run with it. I am just a bit concerned about talk of patents...

[StuartJPP]

1 hour ago, themos said:

I always wanted other people to take the idea and run with it. I am just a bit concerned about talk of patents...

Prior art is already out there so I don't know what specifically about their implementation is "novel" and patentable. Plus the Chinese patenting something is a bit rich...they are the first to rip off other people's ideas.

Rick Kellogg produced a document in 2012 called "Electronic Polar Alignment Scope", which effectively covers what they have done.

I would have run with it, but I am not a cross platform person...I would have made it very specific for my kit hence very easy to use. Adding support for other platforms and various kit and cameras would be a lot more of a challenge and not my forte. I already own a couple of QHY5 cameras and got parts working via their SDK. But that is for Windows only and I wouldn't have taken it further than that...although I would have shared it if anybody wanted it but it is all moot at the moment...

The best people to pick this up would be the PHD2 guys, as the majority of the support for various platforms and kit is already there.

[Dr_Ju_ju]

For the questioner asking about what version to get for an AZEQ6, you just need to get the EQ6 version. 

If you want to check if it will fit, if you have a digital Vernier, measure the diameter of the top hole, & then look up the adaptor dimensions on the QHY site. Measuring the openings on my other mounts & after mailing Bernard @ Modern Astronomy

(superb service BTW), I also bout the AVX adaptor as a separate buy, so can now move the one camera between multiple mounts   

And yes I will be taking it to SQLXI, so if anyone wants to look.....

[PeterCPC]

This is my first image after doing a PA with Polemaster. The stars are nice and round and I got very good guiding. The Polemaster seems to be performing well.

Peter

[Mav359]

Nice, in itching to have a go but the weather doesn't look good for the next few days

[StevieDvd]

I've had one of those out of the blue ideas, which I present to you here to knock back where it came from.

Could you use the polemaster as a guidescope?

The benefits are the placement and secure mounting point.  I guess the limited field of view and the choice of stars would be an issue and the guide software would see the guide star movement as being a lot slower, but what else could be a show stopper?

I guess if you own one you should be able to give it a go.

 

 

[PeterCPC]

There is no ST4 connection for a start.

Peter

[Davey-T]

If  you're properly Polar aligned the stars won't "move" at all, only rotate around pole.

Dave

[StevieDvd]

16 minutes ago, Davey-T said:

If  you're properly Polar aligned the stars won't "move" at all, only rotate around pole.

Dave

Theoretically then no guide software would be needed.  PA just means your axis point is correct, the 2/3 star alignment tells your goto system you are pointing at the right places at first - then inaccuracies such as motor speed can lead to going off the star.

What I am thinking is that these errors are more the further from the axis of the mount the guide camera is and allows for the errors to be detected and corrected more easily. So  the polemaster placement may not be ideal.

I did consider if the polemaster could be pointed off axis to a star that moved more it would work better - but that would involve a movable adapter. If QHY made a poseable adapter those who no longer needed it for PA could have a guider instead, or the product could be bought for PA or guiding with the right adapters (or both).

 

[Davey-T]

Probably cheaper to buy a QHY5  and guide with it, the more accurate the Polar aligning the less work the guider has to do to correct errors in the mount mechanics unless you spend loads of money for a mount that can run unguided.
Mounts like the 10Micron are  indeed accurate enough to run unguided after they've worked out where they are .
The longer your focal length the better your guiding / mount needs to be so if you have an HEQ5 and a wide field refractor there's no point spending lot's of time and money getting perfect PA, time better spent imaging.

Dave

[StevieDvd]

3 hours ago, PeterCPC said:

There is no ST4 connection for a start.

Peter

Opps missed that but would it need one if the usb connection was used?

[StuartJPP]

You could guide without an ST4 cable however I am not sure how effective guiding at 30.5 arcseconds per pixel is going to be since the FL is only 25mm. Additionally, as mentioned, it would have to be mounted to the same part that the scope is mounted to (i.e. the declination clamp) but that is possible as it doesn't have to be mounted where the polar scope is usually attached (RA), as long as it can see NCP during RA slewing i.e. the scope/dec is in the "home" position.

 

[StevieDvd]

2 hours ago, StuartJPP said:

You could guide without an ST4 cable however I am not sure how effective guiding at 30.5 arcseconds per pixel is going to be since the FL is only 25mm. Additionally, as mentioned, it would have to be mounted to the same part that the scope is mounted to (i.e. the declination clamp) but that is possible as it doesn't have to be mounted where the polar scope is usually attached (RA), as long as it can see NCP during RA slewing i.e. the scope/dec is in the "home" position.

 

Yes I expected there was likely to be an issue, or two, totally missed the point that there were 2 axis to worry about. Doh! I had not actually checked the spec of the camera as I was unsure if the idea had any real merit.

[themos]

I would like to see some measurements of the achieved PA error with Polemaster. If you're guiding with PHD, the log file can be analysed to compute the long-term declination drift and estimate the polar alignment error.

[nightster]

[knobby]

cant get phdlab running on my pc (wont open anything)

this ran though, not sure what it tells you !

The spikes are me touching the camera to look at my subs...

 

[StuartJPP]

1 minute ago, knobby said:

cant get phdlab running on my pc (wont open anything)

Try using Python 2.7.8 (32-bit) instead of the latest...mine didn't work either until I downgraded it. Pulled my hair out trying to figure it out (newer is not always better!).
https://www.python.org/downloads/release/python-278/

 

Here's my PHDLab result over a ~3.5 hour period. The spikes were sudden severe gusts of wind!

[aramitsharma]

On 03/02/2016 at 21:21, A40farinagolf said:

Sounds promising and I'd like to see one I action - Is anyone taking one to SGLX1? - perhaps it would make a good demo workshop / sales pitch.

Looking at Modern astronomy website there's a specific one for the AZEQ5 mount but I can't see one for my AZEQ6.

Does a std EQ6 Polemaster work on my mount?

 

Just got mine.. will bring it to the SGL XI

 

[Allan the plumber]

Okay without jinxing tonight, I'm going to attempt to use my Polemaster tonight.

As Doug's and Jeff's second part QHYCCD tutorial isn't due out to next week does anyone have a definitive set up for a first use set up and subsequence polar aligning work through

I've read both the QHY website (forum etc)  as well as Ross' guide  but I'm getting a little confused ( not too hard for me) plus the wording and bad translation on the  QHY download isn't helping. Can anyone help with a step by step guide 

Thanks

Allan 

[PeterCPC]

Allan

You will find that once you connect the device it will give you easy to understand instructions.

You connect, then it will ask to to click on Polaris, then adjust a template. Then click on another star after moving the mount. I won't go on because it really is very straightforward once you connect the camera.

Peter

[StuartJPP]

Just to add to Peter's post, once you have adjusted and matched the template and then done the 2x slewing in RA, it is the mount Alt/Azi bolts that need adjusting to move Polaris to the desired position. Make sure you use the latest version of the software (1.14) as there have been issues with previous versions where the position to move Polaris to wouldn't always appear.

I'd run the software before you get out there and just make sure everything works and you can connect to the camera. You can then follow the instructions to get a better idea of what is happening.

[sloz1664]

As Peter implies, it's easier to understand whilst going through the procedure on your PC/laptop next to your mount. As explained previously it is so much easier to use a mouse to fine tune the template alignment and having the PC/laptop next to your mount, it's easier to adjust the ALT & DEC bolts. I've used this alignment procedure on two different laptops and it's so easy to use, and may I add, accurate.

 

Steve

[Allan the plumber]

Thanks Steve, Stuart and Peter. Think the only problem I'm going to have is running two laptops. I did think about this as I'll have to go back to main laptop ( set up in summerhouse) to move mount with ascom and use polemaster on small net book ive got 

 

Will give it a go and again thanks for the assistance, if you here a scream Steve ( as you're in Nottingham) it'll be me lol

[Dave Gary]

Here's an initial polar alignment with PoleMaster. As you can see I used AstroTortilla to calculate the offset. I refined the alignment, later, but this gives one an idea of initial setup values. This initial alignment took about 5 minutes. If anyone needs help with the alignment sequence using PoleMaster (the instructions are a little vague) I'd be glad to accommodate. I really like the PoleMaster camera. No more crouching down to look through the mount's polar-align scope. It is very convenient for me. My mount is an iOptron iEQ30.

However, I'm really impressed with AstroTortilla. I've only used it for a couple of days and it's the greatest program I have for imaging. People on this list have posted it as an accessory in their imaging-equipment lists and I was curious as to what it did, exactly. I downloaded the program and after reading about its setup values, gave it a try. Boy, am I glad I did. I am a fan of plate-solving algorithms, now. A big fan. It's so nice not having to trundle over to the scope, grab the controller, look through the finder scope and then center the target on the CCD chip. AstroTortilla is fast, the price is right (free) and it's extremely accurate. Plus, features such as "Polar Align" make the program that much better. Whoever wrote this program is a genius.