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The Great Hercules Cluster with a Stellarvue SV80ST2 and ZWO ASI183MM

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#1 james7ca

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Posted 11 June 2021 - 05:02 AM

Okay, finally a clear night with no moon! I thought last night was going to be clear, but it clouded over less than one minute into my sequence (yes, it was completely clear and with a "good" forecast when I finished my setup, but things went bad almost immediately thereafter).

 

I'm still working toward my bi-color Pelican Nebula but while waiting for that target to appear above my roof I imaged M13 using a Stellarvue SV80ST2 refractor with a 0.8X reducer and a ZWO ASI183MM Pro camera with Baader RGB filters.

 

Captured with Sequence Generator Pro and PhD2 (guided with a SVBONY 30mm, f/4 scope and ASI290MM). Image processing with PixInsight and Photoshop CC2021. This shot had minimal processing with no calibration files and is a 50% reduction and crop from the 20 mega pixel original. The total integration time was one hour and twenty-one minutes (just under thirty minutes for each filter).

 

If I'm lucky (again) then I should be able to double the integration time tomorrow night.

 

It's interesting to compare this image with one that I took using a 50mm guide scope and an uncooled ASI290MM camera a few weeks ago under a gibbous moon (i.e. not a great night), and with just 30 minutes of total integration time:

 

  https://www.cloudyni.../#entry11130608

 

C&C Welcomed.

Attached Thumbnails

  • The Great Hercules Cluster with SV80ST2 and ASI183MM (small).jpg

Edited by james7ca, 11 June 2021 - 07:08 AM.

  • elmiko, chrysalis, happylimpet and 10 others like this

#2 Enance42

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Posted 11 June 2021 - 09:28 PM

The picture taken with the 290mm looks pretty good considering the short integration time. The 183mm is much better though im my opinion. I am impressed how it looks even with no calibration files. I had the 183mm arrive on my doorstep this morning. I am jumping from DSLR to mono and this gives me hope. Thank you.

#3 james7ca

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Posted 11 June 2021 - 10:56 PM

The biggest change in the results comes from the difference in the scopes. That shot done with the ASI290 used a simple finder/guider scope (50mm, f/4 achromat). In fact, the ASI290MM camera was two times the cost of the scope that was used to make the image. The 50mm, f/4 finder was just $145 in cost (new) and that included the 1X Crayford focuser (which is just barely adequate for imaging).

 

As for the ASI183MM image, I had to crop out the amp glow (since I didn't use any calibration files). Full frame (with the amp glow) and I would have definitely needed darks. Plus, the SV80ST2 setup was over ten times the cost of the 50mm finder.


Edited by james7ca, 12 June 2021 - 06:06 AM.


#4 Enance42

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Posted 12 June 2021 - 12:40 AM

The scope definitily makes a difference. I will have mine on a Redcat51 for the time being. I have read that the amp glow calibrates out easily if you know what your doing.


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