Tilt,coma or colimation?

[spillage]

Hi All,

I am just trying to save some time in working out the issue I am having. I am using a baader cc with my 130pds. I am right in thinking this is a combo of tilt and colimation or have I got my coma at the wrong distance. I understand if tilt is an issue it will throw things off a bit.

Any help or advice would really be appreciated.

 

Thanks

Spill.

 

 

I ran an image through ccd inspector but not really sure what it all means.

Min FWHM: 3.76px

Max FWHM: 5.57px

Curvature: 41.1%

Tilt in X: -1.3px

Tilt in Y: -0.4px

Total Tilt: 29% @155  Arrow pointing at about 10 o'clock

Collimation: 8.9px (not sure if this is good)

 

 

[spillage]

I have tightened the cc as much as it will go and sorted out the tilt.  But still not sure if this is good enough.

 

[alacant]

Hi. The cc is too far away from the sensor in the first snap. Sorry, no idea about ccd inspector but to my untrained eyes and having a lot of zeros in the numbers, it looks dead centre:) HTH.

[Uranium235]

As above, the first image inicates that the spacing is too long. You need to take length off it in 1mm increments until it improves.

[spillage]

Thank you both for your input. I am going to have to spend some time finding out if 16.9% curvature is acceptable or if this can be improved on. As it stands I have know idea. The initial image and results were of my errors. Putting the 2" filter between the t2 and cc and not realizing that in the dark I had caught the power lead to the camera between it and the focuser. 

cheers

Spill.

[alacant]

1 hour ago, spillage said:

Putting the 2" filter between the t2

Hi. That's good because it removes the star halos you get with it at the front of the cc, but you'll need one of these. HTH.

[spillage]

I have only just got a new baader t2 and it showed the filter behind the nose piece so I thought I would try it with the cc. So I moved to in front of the cc and took another image with is the second ccd inspector report.

The t2 does a really good job compared to my old generic ones but still not found out if the curvature reading is good or bad.

[alacant]

2 hours ago, spillage said:

only just got a new baader

One of these perhaps? If so, you're good to go.

[spillage]

This is what I have not sure if I have the t-ring spacer though ther may be one in the cc kit and my filter is mounted so not sure if you can unmount them easily.

[alacant]

Ah, OK. I think you maybe missing this. HTH.