Funny line on my images...

[LeoG]

Hi All,

I wonder if anyone could point me in the right direction. I recently bought a QHY10 and every image I end up with seems to have a dirty grrt line through it. I initially thought it was a satellite so I checked my subs but it's on all of them. A friend suggested it might be some kind of sensor/computer interference which could be combatted with darks but I'm not so sure. This rough image is 130x50s subs & 30x50s darks. Any ideas about what it is and how I can deal with it would be greatly appreciated. I'm hoping it's not a problem with the CCD. 

Thanks in advance

[Cornelius Varley]

The vertical lines goes through the brightest light source in the photo so it might be a diffraction spike. What telescope are you using and has the problem appeared on other image sets ?

[LeoG]

Hi Peter, Thanks for the reply. The scope is a little William Optics ZS71. As the QHY10 is so new I've one used it three times twice on M42 and once on M45. All have this line. Vertical from any orientation.

[Cornelius Varley]

There also appears to be more vertical lines to the right and left passing through other bright stars.

[Davey-T]

Is it there on dark frames ?

Looking at it in P'Shop it looks about 6 pixels wide so not just a 1 pixel line which some manufacturers think is acceptable, could be a faulty sensor.

As noted there are a couple of others.

Dave

 

[LeoG]

Hi Dave, 

That's what my gut feeling was. I hadn't thought to measure the pixel width in PS, good call.

It doesn't seem to be on the dark frames which gives me hope. It's not beyond the realms of possibility that it's my own fault somehow

I appreciate you taking the time to help me.

Leo

[Louis D]

Looks like CCD line saturation.  Read up on it here.

[Davey-T]

50secs shouldn't saturate the CCD.

Try a 10sec exposure to see if it's still there and try a bit of sky with no bright stars.

Dave

[LukeSkywatcher]

On 05/02/2017 at 11:50, Davey-T said:

Is it there on dark frames ?

Looking at it in P'Shop it looks about 6 pixels wide so not just a 1 pixel line which some manufacturers think is acceptable, could be a faulty sensor.

As noted there are a couple of others.

Dave

 

There is at least 4 lines there, so we can rule out aircraft or satellites. Beyond this.......i bow to the superior knowledge of imagers.

[ollypenrice]

I think it will be electronic and probably an issue with this particular camera, unfortunately. Although you will want a proper solution, AstroArt has a 'repair row' and 'repair column' feature in its stacking and calibrating section. You mouse over the row to find out which one it is numerically and then type this into the 'repair row' box on the third page of the Preprocessing menu. I think you can download a trial AstroArt which does everythng except allow you to save, so you could see if it worked. Other stacking software will have a smilar function. AA also has a 'repair line' feature which works well.

The odd single pixel line is all but inevitable with a CCD as it's exposed to cosmic ray strikes etc and is absolutely not a problem if you use a repair algorithm when stacking. However, your row is more serious than this.

Olly