Stacked image issue

[WiltsStarGazer]

Hi, 

does anyone know what these faint red blue and green  'L' shaped lines in the attached image are?

And more importantly how to get rid of them.

They are a uniform shape and size and all across the frame.

I don't seem to get these lines on single images, at least I can't see them. 

I have tried stacking through both Deep Sky Stacker and Sequator, and even used a different laptop but with the same result. 

The pictures were taken on a Canon EOS 450D through a Skywatcher 200P mounted on a EQ5 Pro.

The mirrors seem ok and I don't have any issues when visually observing.

Any help and advise gratefully received.

Thanks

[carastro]

I have a feeling they are walking noise, i.e. hot pixels which when stacked looks as though they have moved because the image itself moved.  

Carole 

[vlaiv]

Those are hot pixels and are removed by using sigma rejection stacking technique.

[almcl]

If you are using Deep Sky Stacker you may need rather more lights (25+) for the Sigma Clip stacking algorithm to work.  

If you are guiding (not sure from your equipment list) dithering may also help, although again you need quite a few lights otherwise you get a cloud of coloured dots rather than a line.

[WiltsStarGazer]

Thank you for your replies, it did seen to be 'hot pixels'. 

I adjusted the settings on DSS and they disappeared.

I used those settings to stack the Orion Nebula I took last week.

Thank you again for your help.