Hot/Cold Pixels

[Harry page]

Hi

have had a go with your subs and CC works very well 

Are you saying you can not remove any hot pixels at all , or not as many as you would like ?

Harry

[sreilly]

What I'm saying is that I could not get the preview feature to work and my resulting image showed many hot pixels not removed. Refer back to the cropped image in the 10-11th post in this thread for the cropped example. What settings did you end up using? Maybe I could use that, do the stack and post the result?

-Steve

[Harry page]

Hi

I will a quick video 

Harry

[Harry page]

Hi

Small video for you

http://www.harrysastroshed.com/Temp.html

Harry

[sreilly]

Thanks Harry, downloaded as we speak.

-Steve

[sreilly]

Harry, thanks for your efforts. Two things come to the surface here. 1) may be a good time to redo my darks. Plenty of time for that with our lousy weather of late. 2) I wasn't aware I needed to open an image, draw a preview, and then select the preview before using the preview button in the CC tool.

Yes, it does work as expected now that I see what I was doing wrong. Maybe I need to process my data during the day rather than late at night

Thanks again Harry.

[Harry page]

Hi

You can use your whole image for a RTP , its just that you can not see whats going on    , hence why I use a preview

Glad we are all sorted

Harry

[sreilly]

Makes total sense. What I'm wondering is if anyone has thought about making it so we can zoom or re-size the preview so we can see the effects better? Another thought, I re-did my -30-600 second darks last night and created a new master. That works fine and does take out more hot pixels but then I thought, can you use a master dark that is say 1200-1800 seconds? Normally you would also use a bias frame and scale the dark when you calibrate the image but can this longer dark be used for cosmetic correction?

-Steve

[Tom OD]

I've been testing out image stacks and practising using PI for image calibration. I'm not getting good results, my older software astroart5 is doing a better job at the moment. See the screenshot.

I used auto select for the hot and ocld pixels and alos a manual setting. I was wondering though if the issue may be that I had the master dark made in AA5, when I was using it to compare the two calibrations. I think I deleted the dark fit subs to save some space and just kept the master file. Should PI calibration with flats and Darks only be used if those flats and darks were made by the batch process script in PI, or should it work just as well with an imported dark from a different s/w? The bright star caused a big issue I see from the post DBE and histo stretch.

Thanks Tom.

[Tom OD]

And the second screenshot.

[Tom OD]

Found the FIT files and made a Master Dark in PI. I used this on 12 600s Lum panes with a flat made from AA5 (Don't have those fits). Played about with the manual hot and cold pixel settings and it made a big difference. This time it worked. There is still a problem with the bright star region though. Any ideas as to whats going on here? If its a hot pixel setting issue shouldn't it be more evident for the star core, and all other stars?
There is better shaprness to the PI stack.
Thanks Tom.

[Harry page]

Hi Tom

I do not think this is to do with CC , I have seen this when the sigma rejection is set to high or there is a sub that differs

from the most i.e a misty sub

Harry

[Tom OD]

Thanks Harry (And good video by the way),
I'll go through each sub and check the background values. For once I really want to try and process a picture in PI from start to finish, this means a lot of reading, study, mistakes, repeat all those, and then cry for help on the forum.
As for the sigma rejection, is this the "Sigma high" slider in the Image Intergration section?

. T

[Harry page]

Hi

Yes thats the sigma setting , but always check your rejection maps 

I will have a penny on a bad sub

Harry

[Tom OD]

I turned it down and that worked a treat. The rejection map looked good and removed a sat trail too. The map also had held back a larger halo area around the bright star. So far so good. I need to work more on the Image Intergration bit too. Need to figure out how to add that to the process script. You don't seem to be able to add it like you can the Cosmetic correction by selecting a drop down of a saved process icon.
Thanks Again.