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Full Discs and Fun Composites from 7 March 2021

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#1 TheCrimson_King

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Posted 07 March 2021 - 10:12 PM

https://imgur.com/a/vNSqQ7l

 

Really happy with how the white light image turned out. The big looping prominence was fun to observe and image.

 

How much more do you think I can get out of my H-alpha setup? I'm using a Lunt 50mm SS with a IMX 178MM sensor. I think I could probably improve in focusing, tuning, acquisition, and processing. I'm trying to get a handle on if I'm even close to the physical limits of the system.

 

Any tips on colorizing images? I've tried a few different things in GIMP and I'm never really satisfied with how it looks.


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#2 rigel123

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Posted 07 March 2021 - 10:20 PM

https://imgur.com/a/vNSqQ7l

 

Really happy with how the white light image turned out. The big looping prominence was fun to observe and image.

 

How much more do you think I can get out of my H-alpha setup? I'm using a Lunt 50mm SS with a IMX 178MM sensor. I think I could probably improve in focusing, tuning, acquisition, and processing. I'm trying to get a handle on if I'm even close to the physical limits of the system.

 

Any tips on colorizing images? I've tried a few different things in GIMP and I'm never really satisfied with how it looks.

Give us a bit of insight to your capture/processing steps.  Is your computer shaded so you can see the screen well, do you crank up Gamma to aid in getting sharp focus, how may Frames are you capturing and how many do you stack, etc.  As to tips on colorizing, I don’t, but others will give you some good pointers.


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#3 MalVeauX

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Posted 07 March 2021 - 10:21 PM

Nice captures, good comparisons!

 

Very best,


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#4 TheCrimson_King

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Posted 07 March 2021 - 10:52 PM

Give us a bit of insight to your capture/processing steps.  Is your computer shaded so you can see the screen well, do you crank up Gamma to aid in getting sharp focus, how may Frames are you capturing and how many do you stack, etc.  As to tips on colorizing, I don’t, but others will give you some good pointers.

Computer is not shaded. I have to go to a public park to image because I can't do it from where I live frown.gif so my setup is on the lean side. I have seen people use tubs turned on their sides for shade and I could probably do that.

 

I have not been adjusting gamma. I usually sweep the focus back and forth until I think it's good. On a related note, for etalon tuning I usually over-tune (error on higher pressure) and back off until I maximize field uniformity. I actually feel like there is a wide pressure range where I see H-alpha features, but the further "off-band" I am the lesser the field uniformity. I haven't used flats for any of my images.

 

I have been capturing 250 or 500 frames (2 ms, lowest gain setting) and keep the best 20%. One time I used PIPP to crop and center, but I found I don't need to and have stopped using it. I use AS!3 to estimate quality and stack. I use Registax 6 for wavelets. I use GIMP to touch up proms (burn/dog), colorize, and crop. I usually make small adjustments to brightness/contrast.



#5 rigel123

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Posted 08 March 2021 - 06:54 AM

Computer is not shaded. I have to go to a public park to image because I can't do it from where I live frown.gif so my setup is on the lean side. I have seen people use tubs turned on their sides for shade and I could probably do that.  Definitely use something like a box or even a towel over your head and screen which should help with focusing.

 

I have not been adjusting gamma. I usually sweep the focus back and forth until I think it's good. On a related note, for etalon tuning I usually over-tune (error on higher pressure) and back off until I maximize field uniformity. I actually feel like there is a wide pressure range where I see H-alpha features, but the further "off-band" I am the lesser the field uniformity. I haven't used flats for any of my images.  Are you tuning while actually looking through the scope?  It is the best way to make sure you have the entire disk within as much of the “sweet spot” as possible.  Turning up the Gamma while focusing helps you again by concentrating on high contrast areas.  You can then turn it off to image.

 

I have been capturing 250 or 500 frames (2 ms, lowest gain setting) and keep the best 20%. One time I used PIPP to crop and center, but I found I don't need to and have stopped using it. I use AS!3 to estimate quality and stack. I use Registax 6 for wavelets. I use GIMP to touch up proms (burn/dog), colorize, and crop. I usually make small adjustments to brightness/contrast.  Sounds good, the more you capture and practice the better your images will get, particularly if you can capture during times of good seeing!  Have fun!


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#6 TheCrimson_King

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Posted 08 March 2021 - 09:15 AM

Thanks for the tips! I'm going to try playing with gamma for sure.
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#7 PhotonJohn

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Posted 08 March 2021 - 09:56 AM

Try using ImPPG instead of Registax for smoothing. Works much better for solar. IMO.
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#8 TheCrimson_King

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Posted 08 March 2021 - 12:26 PM

Try using ImPPG instead of Registax for smoothing. Works much better for solar. IMO.


Never used ImPPG before, but I'm going to try it tonight or tomorrow. Would be cool to do a side by side comparison
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#9 PhotonJohn

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Posted 08 March 2021 - 12:58 PM

Never used ImPPG before, but I'm going to try it tonight or tomorrow. Would be cool to do a side by side comparison


ImPPG at 32:45 mark of this youtube.

https://www.youtube....h?v=-zD4EIGBess
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#10 ATL Gator

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Posted 08 March 2021 - 07:06 PM

Very nice disks. I defer to the more experienced members in this forum when it comes to imaging advice, but I can offer a few suggestions from a beginner's perspective:

  • I agree that you need to shade the computer screen in order to properly focus and fine-tune your settings. I've been throwing a windbreaker over my head when I need to look at the screen -- not the most elegant solution but it works.
  • If your LS50 is like mine, the "sweet spot" isn't perfectly centered in the field of view. If you're having trouble getting the entire disk on-band and evenly illuminated, experiment with moving it around in the field of view. 
  • The image will appear brightest when you are completely on-band. I find that it's helpful to watch the histogram while turning the pressure tuner.
  • Others may have different thoughts, but I'm not sure that 250 or 500 frames is enough. I usually capture 1,000 - 2,000, then evaluate the quality graph in AutoStakkert to decide what percentage of frames to keep (usually 5% or 10%).
  • If you haven't already, check out the excellent YouTube tutorials by Marty/MalVeauX -- search under "Wise Imaging."

Good luck!


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#11 TheCrimson_King

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Posted 08 March 2021 - 10:54 PM

ImPPG at 32:45 mark of this youtube.

https://www.youtube....h?v=-zD4EIGBess

Great tutorial. I am still working on learning ImPPG. My (really old) computer was really struggling during the deconvolution and I couldn't get good results right away, so I'll need to give it another go. 

 

The colorization in the video is exactly what I was looking for. I recolored the disc from my first session and it looks so much better.

 

OLD

11_59_43_lapl6_ap1981.jpg

 

NEW 

The Sun on 7 March 2021 in Hydrogen Alpha

 

Very nice disks. I defer to the more experienced members in this forum when it comes to imaging advice, but I can offer a few suggestions from a beginner's perspective:

  • I agree that you need to shade the computer screen in order to properly focus and fine-tune your settings. I've been throwing a windbreaker over my head when I need to look at the screen -- not the most elegant solution but it works.
  • If your LS50 is like mine, the "sweet spot" isn't perfectly centered in the field of view. If you're having trouble getting the entire disk on-band and evenly illuminated, experiment with moving it around in the field of view. 
  • The image will appear brightest when you are completely on-band. I find that it's helpful to watch the histogram while turning the pressure tuner.
  • Others may have different thoughts, but I'm not sure that 250 or 500 frames is enough. I usually capture 1,000 - 2,000, then evaluate the quality graph in AutoStakkert to decide what percentage of frames to keep (usually 5% or 10%).
  • If you haven't already, check out the excellent YouTube tutorials by Marty/MalVeauX -- search under "Wise Imaging."

Good luck!

Good feedback.

  • I need to get the focus right. Any resulting image will be limited if that's not spot on.
  • I have the same experience with my LS50! My sweet spot was in the upper right quadrant of my sensor.
  • I'll pay more attention to the histogram while I tune. I'm still getting a feel for this one.
  • I'll aim for 1,000-2,000 next time. In reviewing my captures, I realized I made two critical acquisition errors. First, I was effectively 2x2 binning, halving my sensor's resolution. Second, I was stopping the acquisition short, so I didn't actually reach the 100/250 frames I was aiming for.
  • I watched one of Marty's tutorials before I started. At some point I should circle around and rewatch because I probably missed a bunch of things because I didn't know what I was doing yet smile.gif

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