#1  
Old 15-12-2014, 11:49 PM
batema's Avatar
batema (Mark)
Registered User

batema is offline
 
Join Date: Jul 2006
Location: Sunshine Coast
Posts: 1,810
Help please. Guiding AP1100.

Hello,

I am sitting under the stars imaging M42 and am still very much learning or even getting going using my AP1100 with W/O 110Flt and SBIG 8300m with self guiding filter wheel and using Maxim Dl v6. How's that for a learning curve!!!!!!

I am posting an image of my screen in Maxim Dl to see if people could tell me what information this is portraying. I am concerned with the X error shown in the graph and do not know why it is raised???? I have done what I believe to be a pretty good polar alignment using PHD 2.

I have also attached a out of the camera 30 minutes hydrogen alpha shot with the guiding done through the SBIG self guiding filter wheel in maxim to give an indication of my guiding and polar alignment. The guiding is set to 4 seconds exposures.

Finally when I use the guiding function in maxim I go expose and then calibrate and as it moves the star a red line goes up then back and right and left but as the star comes left it does not return along the red line as shown in the third image attached.

Any help with this would be greatly appreciated as I have used an EQ6 Pro for several years but this new system is really foreign to me.

I must admit I am stunned by both mount and camera at their simplicity as I thought they would be daunting but I can get up and running in more or less the same time as I use to on the EQ6. Very simple but magnificently engineered.

Thank you,

Mark
Attached Thumbnails
Click for full-size image (Screen shot 2 reduced.jpg)
188.8 KB48 views
Click for full-size image (M 42 30 min Ha-001Ha reduced.jpg)
191.0 KB36 views
Click for full-size image (Screen shot guiding reduced.jpg)
170.3 KB47 views

Last edited by batema; 16-12-2014 at 12:03 AM.
Reply With Quote
  #2  
Old 16-12-2014, 11:35 AM
DJT (David)
Registered User

DJT is offline
 
Join Date: Nov 2011
Location: Sydney
Posts: 1,352
Hi Mark

That third image with the X Error.

Did you leave a Bhatimov mask on? Strange shaped stars and diffraction spikes which you wouldnt expect from the refractor?

The peak on the 3d star image is flat across the top a well which the Maxim help guide indicates the guide star is saturated so not a good candidate but suspect the mask was in place when you did this grab?


Just a thought

Gotta love the learning curve. Enjoy
Reply With Quote
  #3  
Old 16-12-2014, 12:26 PM
Peter.M's Avatar
Peter.M
Registered User

Peter.M is offline
 
Join Date: Sep 2011
Location: Adelaide
Posts: 914
The x error is fine imo, if you look at the numbers it is guiding well and x returns back to the same pixel in maxim. The y on the other hand is offset from the 0 point and does not return to the same pixel in the calibration but drifts as the calibration runs. I suspect polar alignment is off, if you are setting up fresh every night I have found alignmaster to be great. If it's observatory mounted you might want to spend more time on driftaligning.
Reply With Quote
  #4  
Old 16-12-2014, 12:30 PM
Peter.M's Avatar
Peter.M
Registered User

Peter.M is offline
 
Join Date: Sep 2011
Location: Adelaide
Posts: 914
Just to be sure the graph and the numerical display in maxim (camera 2 window) have the opposite data displayed in them. The graph depicts the x axis offset and the numerical displays the y offset.
Reply With Quote
  #5  
Old 16-12-2014, 12:36 PM
niharika
Registered User

niharika is offline
 
Join Date: Jun 2012
Location: melbourne
Posts: 205
Hi Mark,
What settings did you use to calibrate the guide star? In short, following gives good result with AP:
- Calibrate close to equatorial meridian.
- Calibrate for atleast 10sec and if possible do it for 15/20sec
- Post a screen shot of guider settings screen. 2nd image in the link http://www.cyanogen.com/help/maximdl/Autoguiding.htm

I think in your image axis is flipped. in the Graph x is DEC and not RA. To make debugging easier either flip the axis in maxim or change your camera orientation so that RA button moves the guide star horizontally and Dec button moves the guide star vertically.

From what I see from the pictures, in your guide graph X is DEC. and its drifting up and then brought down by correction but not enough. It's also drifting faster than my liking indicating something went wrong during polar alignment (probably the reason why guide star does not return in the same spot when calibrating). Try to bring the Dec drift < 1 pixel for 5min.

Try to select a guide star which is not Saturated, this is very important.
Reply With Quote
  #6  
Old 16-12-2014, 12:45 PM
RickS's Avatar
RickS (Rick)
PI cult recruiter

RickS is offline
 
Join Date: Apr 2010
Location: Brisbane
Posts: 10,584
G'day Mark,

Quote:
Originally Posted by niharika View Post
- Post a screen shot of guider settings screen. 2nd image in the link http://www.cyanogen.com/help/maximdl/Autoguiding.htm
While you're at it, a screen shot of the Advanced Guider Settings tab would be useful too so we can check your min/max move settings are reasonable.

Cheers,
Rick.
Reply With Quote
  #7  
Old 16-12-2014, 03:03 PM
batema's Avatar
batema (Mark)
Registered User

batema is offline
 
Join Date: Jul 2006
Location: Sunshine Coast
Posts: 1,810
Hi all and thank you for your responses.

I apologise for what is possibly the most ridiculous attempt at what I have been trying to do as it could be all wrong.

David: I did not have the Bhatimov mask on. This is the image of the guide stars that comes from the self guiding filter wheel. The stars come in initially as cigar shaped but this is the best I can get them as if I keep focussing they become cigar shaped in the opposite axis and they are not round unless I have the exposure (don't know how to set that as I just started using 4 seconds as seen in the image). The other thing is when I try to get the guiding going I don't know how to select a guide star. I thought the computer just did it automatically. Is there somewhere where I can pick a guide star and should I change the 4 to maybe 0.5?

Peter: I did set up last night and with the weather will probably have to pull down tonight but I use PHD2 to do my aligning and it uses graphs and a line of best fit as you drift in both axis. I went backwards and forwards maybe three or four times and the lines were more or less perfectly flat so I thought my alignment was OK. Sorry Peter but I don't quite understand the comment in your second post re camera 2 window.
I did just put the camera in like vertically but I do notice that I have to hold the hand paddle sideways to move the stars in the direction I want. Should I rotate the camera??? so up on the paddle causes the star to go up and etc.

Niharika: Thank you and I have looked quickly at the link so will go over that again. I just put the camera so that the camera's filter wheel has the longest side of the rectangular shape of the filter wheel pointing to the ground when the scope is in the park position. I made mention of this in response to Peter just above. I thought my alignment was OK as per comments above but I do not know how to get the dec drift to less that 1 pixel per 5 minutes. And as bad as it sounds I am not sure how you select a guide star in the guiding process.

Rick: Hi Rick. I will do this tonight.

Thank you all for your responses. I will look at the maxim tutorial today and if you could advise me on any of my responses that would be wonderful.

I remember when I first got my (sorry the schools) HEQ5 and ED 80 I thought I finally had things under control and when we would catch up with a good friend he would look in disbelief at what we were doing and tell us the correct way to do things. This occurred on a number of occasions. I suspect the same is going to occur here. I look forward to the journey.

Thanks

Mark
Reply With Quote
  #8  
Old 16-12-2014, 08:34 PM
Peter.M's Avatar
Peter.M
Registered User

Peter.M is offline
 
Join Date: Sep 2011
Location: Adelaide
Posts: 914
Quote:
Originally Posted by batema View Post
Hi all and thank you for your responses.

I apologise for what is possibly the most ridiculous attempt at what I have been trying to do as it could be all wrong.

David: I did not have the Bhatimov mask on. This is the image of the guide stars that comes from the self guiding filter wheel. The stars come in initially as cigar shaped but this is the best I can get them as if I keep focussing they become cigar shaped in the opposite axis and they are not round unless I have the exposure (don't know how to set that as I just started using 4 seconds as seen in the image). The other thing is when I try to get the guiding going I don't know how to select a guide star. I thought the computer just did it automatically. Is there somewhere where I can pick a guide star and should I change the 4 to maybe 0.5?

Peter: I did set up last night and with the weather will probably have to pull down tonight but I use PHD2 to do my aligning and it uses graphs and a line of best fit as you drift in both axis. I went backwards and forwards maybe three or four times and the lines were more or less perfectly flat so I thought my alignment was OK. Sorry Peter but I don't quite understand the comment in your second post re camera 2 window.
I did just put the camera in like vertically but I do notice that I have to hold the hand paddle sideways to move the stars in the direction I want. Should I rotate the camera??? so up on the paddle causes the star to go up and etc.

Niharika: Thank you and I have looked quickly at the link so will go over that again. I just put the camera so that the camera's filter wheel has the longest side of the rectangular shape of the filter wheel pointing to the ground when the scope is in the park position. I made mention of this in response to Peter just above. I thought my alignment was OK as per comments above but I do not know how to get the dec drift to less that 1 pixel per 5 minutes. And as bad as it sounds I am not sure how you select a guide star in the guiding process.

Rick: Hi Rick. I will do this tonight.

Thank you all for your responses. I will look at the maxim tutorial today and if you could advise me on any of my responses that would be wonderful.

I remember when I first got my (sorry the schools) HEQ5 and ED 80 I thought I finally had things under control and when we would catch up with a good friend he would look in disbelief at what we were doing and tell us the correct way to do things. This occurred on a number of occasions. I suspect the same is going to occur here. I look forward to the journey.

Thanks

Mark

If you look at the screen shot you posted, where you control both the camera and the guider the window on the left is the star profile, the second window along shows camera ones information, in this case "exposing light" "155 of 240" ect ect. The third window shows your guider and its errors. You will notice that contrary to what it is graphing, it is reporting the X errors to be low numbers and the Y errors to be offset by just over a pixel.

Oh and to select a guide star manually, in maxim you just click on one you like in the guider frame, you will know it has changed the star because the coordinates will change in the camera window. And at the bottom of the screen it will report ADU values so you know it isnt saturated
Reply With Quote
  #9  
Old 16-12-2014, 09:30 PM
DavidTrap's Avatar
DavidTrap (David)
Really just a beginner

DavidTrap is offline
 
Join Date: Jun 2009
Location: Brisbane
Posts: 2,828
I think your guide stars are blooming and the software is having difficulty finding the centroid. Do you need a 4 second exposure? You can always introduce a delay after correction on the advanced tab.

DT
Reply With Quote
Reply

Bookmarks

Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 09:57 PM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Advertisement
OzScopes Authorised Dealer
Advertisement
Star Adventurer
Advertisement
Celestron RASA
Advertisement
EQ8-R
Advertisement
Lunatico Astronomical
Advertisement
Astromechanics
Advertisement
Bintel
Advertisement
Astronomy and Electronics Centre
Advertisement