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Cassiopeia play time.


MARS1960

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This is a widefield of Cassiopeia, about 35 subs of 60s stacked in DSS, despite reading PS tutorials till my eyes bled i am still unable to get much out of this.

Please help yourself, i would be grateful to anyone that can draw out the nebulosity to post a list of the steps they used.

Thank you.

1.png

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Just now, Davey-T said:

How wide is wide, you should pick up the Heart and Soul nebula, the Double cluster and maybe M31 if it's wide enough.

Dave

I know, thats what i was hoping to draw out but my processing skills are less than poor hence the post asking for help with processing the image and posting the steps used :)

My effort just looks a mess, despite trying for hours and reading tutorials for hours, maybe i just have some poor data.

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Were you using the 35mm lens ? were you using a light pollution filter ?

There is faint nebulosity in your image, I don't think you have enough data but the Double cluster should show up if it's there.

Here's a single 17 minute exposure using 60Da and 24mm, so a wider field,  Cassiopeia is on end in top centre, you can just make out the central part in yours if you stretch it to death.

You could plate solve it to see exactly where you were aimed

Dave

SW-SA-Canon-24-105--at-24- iso1600,1020secs 60Da.png

 

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Thanks Davey, i haven't got as far as plate solving yet, still trying to get to grips with it all.

I used a 55-250mm lens but it was an EF-S so had to remove my CLS LP clip filter, getting new L lens soon.

I also just bought Carboni's astro tools for PS so i hope that helps with my processing.

Clear skies here tonight again so i'll go out and get more practice in.

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Hey Mark

You can plate solve online by uploading images to  http://nova.astrometry.net/upload

I uploaded your image and got ...

 

1708929.jpg

 

Center (RA, Dec): (302.318, 39.792)
Center (RA, hms): 20h 09m 16.299s
Center (Dec, dms): +39° 47' 32.568"
Size: 12.7 x 8.45 deg
Radius: 7.618 deg
Pixel scale: 45.6 arcsec/pixel
Orientation:

Up is -92.9 degrees E of N

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Can you upload the autosave tif from DSS.

Also before saving, try setting the luminance levels in DSS something like this until you see a grey background and with no stars containing black rings. Note how its aligned with the histogram, that near-vertical line through the peak crams as much bit-depth as possible into the main detail, grey background ensures faint details aren't lost:

DSS settings.jpg

What ISO did you use? There is very little detail in there - a bit, but not much...

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5 hours ago, mike005 said:

Hey Mark

You can plate solve online by uploading images to  http://nova.astrometry.net/upload

I uploaded your image and got ...

 

1708929.jpg

 

Center (RA, Dec): (302.318, 39.792)
Center (RA, hms): 20h 09m 16.299s
Center (Dec, dms): +39° 47' 32.568"
Size: 12.7 x 8.45 deg
Radius: 7.618 deg
Pixel scale: 45.6 arcsec/pixel
Orientation:

Up is -92.9 degrees E of N

Thanks Davey, i haven't got as far as plate solving yet, still trying to get to grips with it all.

I used a 55-250mm lens but it was an EF-S so had to remove my CLS LP clip filter, getting new L lens soon.

I also just bought Carboni's astro tools for PS so i hope that helps with my processing.

Clear skies here tonight again so i'll go out and get more practice in.

 

 

Thats brilliant thanks Mike, saved it to docs, its going to help me a lot.

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2 hours ago, Stub Mandrel said:

Can you upload the autosave tif from DSS.

Also before saving, try setting the luminance levels in DSS something like this until you see a grey background and with no stars containing black rings. Note how its aligned with the histogram, that near-vertical line through the peak crams as much bit-depth as possible into the main detail, grey background ensures faint details aren't lost:

DSS settings.jpg

What ISO did you use? There is very little detail in there - a bit, but not much...

I used to do that  but i was told not do anything in DSS except stack and check embed only when saving, confused!!

It was ISO 1600, i don't have the tiff anymore, it was so not worth keeping. I did buy Carbonis astro tools and had another play but this is all i could get.

I thought i exposed long enough because the histogram on LCD screen looks fine at about 1/3 but when opened in PS the histogram is hard up against the left hand side, even more confused.

cassiopeia2.png

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I believed the 'don't stretch in DSS mantra' as well. The DSS stretch is clumsy and the sliders are over-sensitive, but it can be made to work.

The advantage is you are stretching the full 32-bit data in DSS so if you save BEFORE stretching and you have more than four 14-bit subs you are throwing away data if you then process in a 16-bit application.

 

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14 minutes ago, Stub Mandrel said:

I believed the 'don't stretch in DSS mantra' as well. The DSS stretch is clumsy and the sliders are over-sensitive, but it can be made to work.

The advantage is you are stretching the full 32-bit data in DSS so if you save BEFORE stretching and you have more than four 14-bit subs you are throwing away data if you then process in a 16-bit application.

 

Even more confused :icon_biggrin:

I think my best approach is on the next clear night get an hour or two of data on at least two targets and just play around using both methods, i certainly need the practice so nothing lost.

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