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Help needed with Nebula EAA imaging & Sharpcap

Celestron CMOS collimation EAA reflector
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66 replies to this topic

#51 39.1N84.5W

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Posted 29 August 2019 - 04:04 PM

Open the main histogram at the top. See the digital readout for RGB channels? Once you settle on a sub length then you can adjust the White-R and White-B sliders in the right column. Try and get these two digital readouts to match the green channel (which you cannot adjust).
Finish up, close the histogram, then start your live stacking routine.
During live stacking you can obviously adjust color with those three sliders. If you need to make +very small+ adjustments then click right above or below each color channel's white slider. It raises or lowers the slider without having to otherwise grab-n-drag the slider.
Glad I could help!
Nick

Edited by 39.1N84.5W, 29 August 2019 - 04:07 PM.


#52 GaryShaw

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Posted 29 August 2019 - 04:37 PM

Terrific!
Thank you Nick
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#53 donstim

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Posted 30 August 2019 - 02:40 AM

Just be aware of what you are doing if you choose to adjust color using the camera controls on the right side of SharpCap instead of or in addition to the color controls in the live stacking window.  Remember the quote from the maker of SharpCap that Don quoted in one of his posts:

 

"My approach is to never touch the colour balance controls that come with the camera (leave them at their default settings or set them back to those if you have changed already). The problem is that for most cameras the colour balance is performed as a digital manipulation of the post ADC image data, meaning that it is somewhat destructive to image quality. I believe there are a few cameras where the colour balance controls actually are implemented through separate analogue gains for the R/G/B channels, which would be fine to use, but it is unclear which manufacturers or models work this way."

 

Also be aware that the effect of adjusting the live stacking color controls will not be reflected in the live stacking histogram, but they will be reflected in the small display histogram on the right side.  So, if you try to manually align the color peaks using the live stacking color adjustments, you need to do it by examining the effect on the small display histogram on the right side.


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#54 39.1N84.5W

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Posted 30 August 2019 - 04:45 AM

I'm speaking specifically about the 294mc and 1600 cameras. What's fun about this software is that you can try a bunch of techniques. Nothing is going to burst into flames! Have fun and let us know what works for you.

#55 GaryShaw

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Posted 30 August 2019 - 09:44 AM

Just be aware of what you are doing if you choose to adjust color using the camera controls on the right side of SharpCap instead of or in addition to the color controls in the live stacking window.  Remember the quote from the maker of SharpCap that Don quoted in one of his posts:

 

"My approach is to never touch the colour balance controls that come with the camera (leave them at their default settings or set them back to those if you have changed already). The problem is that for most cameras the colour balance is performed as a digital manipulation of the post ADC image data, meaning that it is somewhat destructive to image quality. I believe there are a few cameras where the colour balance controls actually are implemented through separate analogue gains for the R/G/B channels, which would be fine to use, but it is unclear which manufacturers or models work this way."

 

Also be aware that the effect of adjusting the live stacking color controls will not be reflected in the live stacking histogram, but they will be reflected in the small display histogram on the right side.  So, if you try to manually align the color peaks using the live stacking color adjustments, you need to do it by examining the effect on the small display histogram on the right side.

Thank you Don. I now need to merge all this great advice, test things out and try to distill out the best practices. Yours and others’ input here has already helped improve the quality of what I’m observing. I’ve attached several examples which I hope demonstrate some improvement.

cheers

Gary

 

0EFDA0E9-6271-48F6-800C-5C6C8541B814.jpeg

M101 Pinwheel
Raw16
Bin: 1
Exposure: 8 secs
Gain: 160
Frames: 162
Integration time: 1296 s
Sharpcap 3.2 Pro


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#56 GaryShaw

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Posted 30 August 2019 - 09:49 AM

I still have lots of work to do getting all this to work but watching these objects appear onscreen and then spending time learning about them is real satisfying..as are my interactions with you all in the CN community.

 

6E61898A-8490-49C6-A423-6A809B903524.jpeg

M27 Dumbell Nebula
Raw16
Bin: 1
Exposure: 8 secs
Gain: 207
Frames: 144
Integration time: 1152
Sharpcap 3.2 Pro


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#57 roelb

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Posted 30 August 2019 - 06:09 PM

Just be aware of what you are doing if you choose to adjust color using the camera controls on the right side of SharpCap instead of or in addition to the color controls in the live stacking window.  Remember the quote from the maker of SharpCap that Don quoted in one of his posts:

 

"My approach is to never touch the colour balance controls that come with the camera (leave them at their default settings or set them back to those if you have changed already). The problem is that for most cameras the colour balance is performed as a digital manipulation of the post ADC image data, meaning that it is somewhat destructive to image quality. I believe there are a few cameras where the colour balance controls actually are implemented through separate analogue gains for the R/G/B channels, which would be fine to use, but it is unclear which manufacturers or models work this way."

 

Also be aware that the effect of adjusting the live stacking color controls will not be reflected in the live stacking histogram, but they will be reflected in the small display histogram on the right side.  So, if you try to manually align the color peaks using the live stacking color adjustments, you need to do it by examining the effect on the small display histogram on the right side.

+++ on this advice

Use the auto color align button. Very handy. Must be clicked again after some intermediate stacking.


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#58 GaryShaw

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Posted 30 August 2019 - 06:18 PM

Open the main histogram at the top. See the digital readout for RGB channels? Once you settle on a sub length then you can adjust the White-R and White-B sliders in the right column. Try and get these two digital readouts to match the green channel (which you cannot adjust).
Finish up, close the histogram, then start your live stacking routine.
During live stacking you can obviously adjust color with those three sliders. If you need to make +very small+ adjustments then click right above or below each color channel's white slider. It raises or lowers the slider without having to otherwise grab-n-drag the slider.
Glad I could help!
Nick

Hi Nick

I tried following Carl Smith's Youtube video process and, using a daytime distant view, adjusted the White® and White(B) sliders to align the peaks with the green at around the 20% point as he suggested. I then switched to the 'Live Stack' histo and it was chaos. Whatever I had done on the main menu histo to align the peaks was lost and I'd have to start over again to try to get anything aligned. The chaotic color graphs didn't even give me a clear idea how to start getting them all aligned at any percentage. In fact, that histo has no indication of percentages at all. You note above suggests needing to make only very small color adjustments whereas I'd need major surgery on the live stack histo. Is there something I missed? Does his procedure only work with dark skies?

regards,

Baffled..(gary)

 

Here's a screenshot of the main menu histo

Attached Thumbnails

  • Main Menu Histo.png


#59 GaryShaw

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Posted 30 August 2019 - 06:21 PM

Here's what I got when I closed the main menu histo and opened the Live Stack Histo...don't have any idea what to do with this or how to get the peaks to 20% as he suggests. Thanks for any input.

 

 

Attached Thumbnails

  • LiveStack Histo.png


#60 39.1N84.5W

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Posted 30 August 2019 - 06:48 PM

I've not used a daytime view to do anything with my 294mc. Just nighttime.

#61 GaryShaw

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Posted 30 August 2019 - 07:07 PM

Here you go Gary ... a video on how to use the main histogram. After you watch this it should give you a better idea as well as some hints for using cameras on scopes.

 

The main camera control histogram and its use is shown in the video. You use it to setup the frames so that stacking will work.

 

Without first using that main image control histogram, stacking either wont work or have issues, and your color balance will be much harder to do. 

 

https://youtu.be/c1NarA4_qxY

Howie

See my post 58 which is a follow up to the YouTube link you included in the above quoted post. The video was by Carl Smith and showed how to use the main menu histo to set color balance in advance of going to live stacking. 

 

I tried the process he showed in daylight, as he did, and it worked perfectly. Then tried switching to live stacking histo and found a chaotic histogram. Maybe this all only works with a dark sky. Let me know if you feel I’ve misunderstood sonething(s). 

Thank you

Gary



#62 roelb

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Posted 31 August 2019 - 02:15 PM

I think that stacking daylight objects isn't possible.

#63 GaryShaw

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Posted 31 August 2019 - 02:34 PM

You’re probably right. I’ll try the process tonight.
Thanks for the wake-up note.
Gary

#64 Howie1

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Posted 01 September 2019 - 07:03 AM

No worries Gary ... as per Roel ... you cannot stack in the daytime as there are zero stars to stack. Stacking looks for stars to align each frame. No stars ... no align. Sure it will come out at night. BTW those earlier posts showing your latest stacks were great! Really good first time images! You're on your way. Top stuff mate!


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#65 Astrojedi

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Posted 05 September 2019 - 04:32 PM

Gary,

 

Your issues have nothing to do with the camera. You need to address the following 3 things...

 

1. Make sure you are properly collimated - I am seeing some coma in your images as well.

2. Make sure the scope is in thermal equilibrium - do you bring the scope out every night?

3. Use a Bahtinov focus mask for best focus - incredibly quick and precise.

 

Best of luck... and see my SharpCap guide if you haven't already... https://www.cloudyni...-4#entry9572697



#66 GaryShaw

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Posted 05 September 2019 - 07:43 PM

Gary,

 

Your issues have nothing to do with the camera. You need to address the following 3 things...

 

1. Make sure you are properly collimated - I am seeing some coma in your images as well.

2. Make sure the scope is in thermal equilibrium - do you bring the scope out every night?

3. Use a Bahtinov focus mask for best focus - incredibly quick and precise.

 

Best of luck... and see my SharpCap guide if you haven't already... https://www.cloudyni...-4#entry9572697

Hi AJ

These are great points. 

The collimation sometimes slips off a bit during use due to the loose fit of the Svbony helical focuser I’ve been trying out. I’ll either replace it with a different brand or go back to using just the sled focuser that came with the scope. The Schmidt corrector plate requires that I bring the scope out several hours before any viewing takes place. I used a B-mask but need more practice with what settings and what enlargement to have on while using it. 

Cheers

Gary



#67 Stargazer3236

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Posted 07 September 2019 - 03:12 PM

Under the enhancement tab, try using Unsharp masking. It will give your better sharpened stars and the object in question will also be sharpened.

 

Make sure you focus with the bahtinov mask on a bright star. Do this before you start imaging your nebulous targets. Increase the gain to max and make sure your exposure time is set to 1/4 second or lower. Set Binning to 1X1. Then after you get best focus, set the binning to 3x3 or 4x4 and Sync to target to get the star centered in the middle of the FOV. That will help with goto's after that point on.

 

If you find yourself imaging on either side of the meridian, do a Sync to Target on both sides of the meridian with a bright star. Also check your focus with the mask on both sides of the meridian, so you don't have problems later.


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