Processing help

[greealilee]

After spending a lovely day in the garden yesterday, I managed to capture a lovely solar prom with my PST and altair GP 130M. Looking for somebody who can point me in the right direction regarding processing the image and bring out more detail.

Thanks,

Lee

[steppenwolf]

I don't know if this helps but this was the answer I gave to a 'Scope Doctor' question some years ago:-

My PST instrument only ever shows a plain red solar disc with no surface features. Why don't I see an orange disc [like the images published in astronomical magazines]?

The key to this is image processing! The narrow bandpass Hydrogen Alpha (Ha) filter in the PST is centred on a wavelength of 656.3nm. The red portion of the light spectrum that our eyes can see extends from about 620nm to 700nm so views through the PST will appear red. Likewise, colour images taken through the PST will show a red disc on a black background. The solar image colours displayed in magazines are purely arbitrary and are produced by processing the disc and prominence regions differently in a program like PhotoShop.

The start point, ironically, is a mono image derived from either the red channel of a colour image or directly from a mono CCD camera. After careful sharpening and ‘levels’ adjustment, the image is converted to RGB and duplicated. Next, the ‘Magic Wand’ tool is used to select the area surrounding the disc, including any prominences. The selection is feathered by 3 pixels then deleted leaving just the disc region. The disc is then colourised using the ‘Curves Tool’ to boost the red channel and reduce the blue channel to produce an orange appearance. Finally, the background layer containing the prominences is selected and colourised to a burning red colour by boosting the red channel, reducing the blue channel to zero and reducing the centre point of the green channel to achieve the desired effect.

Original Image from Helen Usher

Image enhanced by stretching and Sharpening

Disc colourised using 'curves'

Prominences colourised using ‘curves’

 

[Merlin66]

I use FireCapture to acquire SER videos (ASI 174 and ASI 1600) then process the video with AutoStarkket3 and finally sharpen with impp or Registax6.

your favourite imaging program for colourising.

 

 

[greealilee]

Thanks guy's.

Well this is what I have come up with so far, your advise is more than welcome.

Processed in AutoStakkert and RegiStak 6

Prom_g4_ap370.tif surface_g4_ap5880.tif

[Merlin66]

Hmmm, pretty good.

I have to ask why is the right hand side of the solar disk out of focus.

 

[greealilee]

Not quite sure, other than the fact I was struggling to see my lap top due to the sun. Think I need to go under cover to see what I'm doing in future. Any thoughts on how to go about putting the 2 images together. I don't have PS.

[Davey-T]

Had a quick hack at it in PS while having lunch, given more time to fiddle could probably be improved, a lot 

Similar can be done for free GIMP in I believe but never tried it.

You could take some flats to try and minimise those Newton rings and uneven illumination by just fitting one of those thin supermarket vegetable bags over the objective, Firecapture can collect flats and Autostakkert can use them.

The uneven illumination could be camera tilt.

Dave

Edited August 25, 2019 by Davey-T

[greealilee]

Dave,

Thank you for this, as silly as it sounds but what is the veggie bag!. I do have Gimp but so frustrating. what can you recommend for future images and again thank you for the quick process it's nice to know that their is people out there  willing to help and share 😀😀😀 

Thanks Dave hope lunch way good.

Lee

[tooth_dr]

5 hours ago, Davey-T said:

just fitting one of those thin supermarket vegetable bags over the objective

Brilliant tip thanks. I defocus but that is a lot handier. 

[Davey-T]

1 hour ago, greealilee said:

what is the veggie bag

The little bags they have in supermarkets for you to put loose fruit and veg in, you can also use cling film, may need a couple of layers.

There are a few tutorials on YT.

Some here

https://brierleyhillsolar.blogspot.com/p/imaging-tutorials.html

Dave

[greealilee]

Dave,

You have just blown my mind, what is this almost black magic. Is it dark web stuff, after doing/trying astro stuff I turned to solar and never did I believe this stuff was out there. You have just added more fuel to my love of the greater cosmos. If not a little sun burnt.

[Merlin66]

Check out Solar Chat forum, the largest solar forum on the net...

The Library files area has many useful tutorials and advice.

https://solarchatforum.com/viewtopic.php?f=7&t=13884

I use PaintshopPro, and you can follow the PS instructions....