Stacked Tiff artifacts issue?

[Rustang]

Does anyone know what could be causing the coloured "pixels" in the stacked Tiff from DDS? Camera files are from a Modified Canon 600D.

They are not present in the Subs from what I can see. Ive done some stack tests and they are coming through even with just stacking the Lights so no Bia's, dark's or flat's. Ive not changed any settings from before.

 

Edited February 5, 2021 by Rustang

[tooth_dr]

15 minutes ago, Rustang said:

Does anyone know what could be causing the colour "pixels" in the stacked Tiff from DDS? They are not present in the Subs. Ive done some stack tests and they are coming through even with just stacking the Lights so no Bia's, dark's or flat's. Ive not changed any settings from before.

 

Stacking with sigma clipping will probably remove them.

[Rustang]

2 minutes ago, tooth_dr said:

Stacking with sigma clipping will probably remove them.

All settings are already on Kappa-sigma-clipping. Ive not changed any settings from when the stacking was working before either.

Edited February 5, 2021 by Rustang

[tooth_dr]

2 minutes ago, Rustang said:

All settings are already on Kappa-sigma-clipping. Ive not changed any settings from when the stacking was working before either.

I am not sure then.  But they must be present in the subs as coloured dots.

[Rustang]

Il look again, if they are then could that be a camera issue? Which I bloody hope not! 

Edited February 5, 2021 by Rustang

[bottletopburly]

You have walking noise you need to dither between frames to eliminate , Startools can help with images showing walking noise 

https://www.startools.org/modules/denoise

Edited February 5, 2021 by bottletopburly

[Rustang]

25 minutes ago, bottletopburly said:

You have walking noise you need to dither between frames to eliminate , Startools can help with images showing walking noise 

https://www.startools.org/modules/denoise

The thing is, I did dither! I've been looking into it and found the same result, that it's walking noise, well walking hot pixels actually! So if I'm dithering, what else can cause it and can it be removed from the subs I've already got with a certain setting in DDS!?. I don't take darks now because I dither. 

Edited February 5, 2021 by Rustang

[Jamgood]

19 minutes ago, Rustang said:

I don't take darks now because I dither. 

Have you got some old Dark files you can calibrate with to see if it removes the walking pixels?

I still use Darks even though I dither after every shot. I find images look better with than without them.

[Rustang]

8 minutes ago, Jamgood said:

Have you got some old Dark files you can calibrate with to see if it removes the walking pixels?

I still use Darks even though I dither after every shot. I find images look better with than without them.

Yeah it's worth a try, they won't be at correct temperature though. I'll also have a look at the settings in DSS and have a play around. This hobby really gets you banging your head against the wall, 1step forward and 2 steps back! 

[bottletopburly]

How many pixels are you dithering, what program are you using to dither

 

[Rustang]

8 minutes ago, bottletopburly said:

How many pixels are you dithering, what program are you using to dither

 

Apt for camera control, I can't remember the dither settings but I'm pretty sure they are set big enough for what a DSLR needs, I've not had this issue until now though and I've been dithering for a few sessions with out this issue! 

[bottletopburly]

Try dithering in spiral movements in phd2 settings assuming your doing it that way

[Rustang]

14 minutes ago, bottletopburly said:

Try dithering in spiral movements in phd2 settings assuming your doing it that way

Il check what its set to, cheers 👍

[Jamgood]

In APT my Dither is set to 12. In PHD2 I have it set to spiral. I'm using a Canon 60Da which is a similar censor.

Another thing, with DSS. Once mine went all screwy for no reason and I couldn't fathom out why. Nothing had changed. I deleted all the temporary files and reinstalled the program and it has worked flawlessly since. I also find it can be temperamental and give mixed results if you don't put the files in order. Lights - Darks - Flats - Bias. 

[wxsatuser]

Try updating the bad pixel list.

Let the camera reach ambient.
Put it in manual mode.
Chose sensor cleaning, second yellow spanner menu.
Chose clean now.
It will do a clean and you should hear the shutter.
Wait till the clean now highlights again.
Then turn off

The bad pixel list should be updated and RAW convertors should discard these pixels.

[Rustang]

7 minutes ago, wxsatuser said:

Try updating the bad pixel list.

Let the camera reach ambient.
Put it in manual mode.
Chose sensor cleaning, second yellow spanner menu.
Chose clean now.
It will do a clean and you should hear the shutter.
Wait till the clean now highlights again.
Then turn off

The bad pixel list should be updated and RAW convertors should discard these pixels.

Thanks for that, i will give it a try! 👍

[bottletopburly]

Out of interest what camera /scope  guide camera /guide scope are you using 

[Rustang]

Ok, so far in regards to the data I have been tryng to stack, I played around with DSS and results so far - Dark's added from another night - didnt work!. What has worked is going into - Register settings -parameters - cosmetic and ticking 'Detect and clean remaining Hot pixels' I set this to 1px as 2px did something to the stars! 1px seemed to reduce the amount of stars in the final stack but i didn't noticed any other issues with the tiff so I'm guessing its ok to do this?

[Rustang]

2 minutes ago, bottletopburly said:

Out of interest what camera /scope  guide camera /guide scope are you using 

A modified Canon 600D, ZWO ASI 120 colour guide cam and Atair 60mm guide scope

[bottletopburly]

17 minutes ago, Rustang said:

A modified Canon 600D, ZWO ASI 120 colour guide cam and Atair 60mm guide scope

What teescope fl or lens fl 

[Rustang]

4 minutes ago, bottletopburly said:

What teescope fl or lens fl 

SW 80ed 600mm fl

[bottletopburly]

Apt dither of 4 and phd2 dither scale of 1 will give you a dither of 18 pixels , apt dither of 3 will give you a dither of 13 pixels .

[Rustang]

8 minutes ago, bottletopburly said:

Apt dither of 4 and phd2 dither scale of 1 will give you a dither of 18 pixels , apt dither of 3 will give you a dither of 13 pixels .

Il double check what its set to in both programs but I'm pretty I'm set to the right settings for my DSLR. Which would you recommend though? I spent some time looking into this and thought I had it sorted and could tick that part off, we will see! 

[bottletopburly]

1 minute ago, Rustang said:

Il double check what its set to in both programs but I'm pretty I'm set to the right settings for my DSLR. Which would you recommend though? I spent some time looking into this and thought I had it sorted and could tick that part off, we will see! 

id try 4 

[Rustang]

6 minutes ago, bottletopburly said:

id try 4 

Thanks. Are you thinking the dither settings could be the issue then? I ticked the 'detect and clean remaining hot pixels' in DSS and set it to 1px, it appeared to remove the problem, I can't see that it has caused anything but I'm hoping it won't cause any other issues in the stacked file.