synguide help needed!

[majestic0110]

Hi all!

I have just bought a Synguider and a star travel st - 80 as a guider scope which I have piggy backed onto my SW 200 PDS on an HEQ5. I am using a canon 500 D camera in the 200 pds. My first attempts at imaging some stars last night were unsuccessful as I had terrible field rotation, even at 5 seconds exposures. I think I have pretty decent polar alignment, I was using the Polar Finder app for android and followed these instructions to the letter:

http://www.polarfinder.com/alignment.html

I have the GOTO handset but I did not perform an alignement with that, also - does the autoguider cable go into the mount itself or the handset?

What is basically happening is I get the star LOCKED in the synguider and then I tell it to AUTO GUIDE CAL, which it does for about 5 seconds (though the star does appear to jump quite a bit in RA), then I get the message - STAR LOST and my images come out with appalling field rotation. I am not sure how accurate my polar alignment is, as I am still pretty new to my EQ mount, but do you guys have any advice at all? I knew astrophotography was a challenge, that's opne of the reasons I decided to pick it up - but I should really be able to get more than 5 seconds on an HEQ5 without guiding surely!

[Cornelius Varley]

The cable from the Synguider plugs into the ST4 port on the mount.

Peter

[Capricorn]

Use the polar scope to align the mount, and do it carefully and accurately. Any misunderstanding by adding in the Android App will cause problems and the less to go wrong the better. Also are the instructions accurate enough for AP or just visual?

I knew astrophotography was a challenge, that's opne of the reasons I decided to pick it up - but I should really be able to get more than 5 seconds on an HEQ5 without guiding surely!

Yes you should. Pretty decent polar alignment is not good enough, very accurate is. Welcome to the world of AP.

I also suspect that you will have to perform the alignment since that is really how the system was intended to be set up. It probably need the alignment to know exactly the amount of correction to apply, thinking that there will be some scaling to determine from the data from the guider. The guider has an X/Y (Alt/Az) grid of pixels and the mount operates in polar coordinates so something may have to do a conversion from the Alt/Az movement of the guide star on the guider to the polar coordinates on the mount.

I think you are trying to get it done a bit quicker and easier by side stepping or reducing a few of the actions required. There is no shortcut. Even buying a laptop and additional software, the club I go to has lots. It does not reduce the time to set it all up, it increases the accuracy, and in actual fact set up time probably increases.

You should not be looking to decrease the time, you should be looking to increase the accuracy.

I would say that unless you are spending the first 60 minutes getting it set up, polar aligned and aligned for goto then you are rushing it.

[Russe]

First setup is super important.

Level the mount. Use polar finder to visually PA. use alignmaster to visually drift align. Pop in your camera and repeat it on screen. Then go for guiding.

[majestic0110]

thanks a lot all of you, I am thinking that my polar alignment is not that great, I have only tried it about 6 times. I guess I need to do some more reading about it. Do you guys have any tips on getting perfect PA?

[majestic0110]

So when I am using the Polar Finder app, presumably the Polaris Peak is the same thing as Polaris Transit? Is that correct?

[majestic0110]

Still having problems actually. Pretty sure PA was OK last night and I spent a good hour and a bit setting up. What happens is the guider AUTO CALs then within about 5 seconds it "loses" the star, it drifts out of the FOV. I think its "over compensating" or something as when I have no guiding on, the star drifts out of the FOV in almost the opposite direction. Is there some setting I need to adjust somewhere?

[AstroG]

I also have this problem ! Did you ever find a solution?

[Cornelius Varley]

9 hours ago, AstroG said:

I also have this problem ! Did you ever find a solution?

This thread is nine years old and the OP hasn't returned since then.

[AstroG]

This will also fix similar issues with phd2 st4 guiding errors such as no drift.

 

So it turns out bad firmware on the motor control unit was the issue.  You need an eq mod cable and the latest firmware from sky-watcher. 2.07 currently. Now the mount is working with the synguider !