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After a 20 year long hiatus - my last astrophoto was captured with a film camera in 1997 - at the beginning of 2020 I decided it was time to start again.
So, January 25th 2020 I brought home my used Sky-Watcher NEQ6 Pro and I immediately started taking photos. Obviously, my first target was M42 in Orion.
This was my first digital astrophotography. 31 subframes, 30s each, taken at ISO800 with my unmodified Nikon D90, Nikkor 70-300mm at 300mm f/6.3 - January 28th, 2020, home front yard, Bortle 5/6 sky, no guiding, no filters. A grand total of 15.5 minutes...
A couple of weeks later, me and my wife went to spend Valentine's weekend in the mountains. Of course I couldn't avoid taking advantage of the Bortle 4 sky and I took all my gear with me. Same target, 52 subframes, 45s each, taken at ISO800 with my unmodified Nikon D90, Nikkor 70-300mm at 300m f/5.6 - February 14th, 2020, Tonadico, Bortle 4 sky, no guiding, no filters. 39 minutes total integration.
After I finished post-processing the second photograph, I was so happy with the result. It felt amazing that I was able to capture so many details and more nebulosity compared to the photo taken from home.
Months passed, gear was changed. First one being the camera: at the end of February I bought a Nikon D5300 and a couple of months later I astromodified it on my own, adding a UV/IR cut filter in front of the sensor, after cutting it to size.
In October the rest of the setup finally arrived: Tecnosky 80/480 APO FPL53 Triplet OWL Series imaging telescope, Artesky UltraGuide 60mm f/4 guide scope and ZWO ASI 224MC guide camera. Also, an Optolong L-Pro 2" light pollution filter.
After months of imaging and getting more experienced with PixInsight, it was just a matter of waiting before I could have another go at one of my favorite targets. And maybe give it a little more justice.
This project took me more than a month, due to the rare clear nights opportunities I have had here lately.
I started acquiring in January and finished a couple of weeks ago.
M42 taken over 8 nights, under my Bortle 5/6 sky.
Total integration time: 18h 04m 00s for the nebula. 714s (14s subs) + 2065s (35s subs) for the Trapezium and the core.
Here are the acquisition details:
Mount: Sky-Watcher NEQ6 Pro
Telescope: Tecnosky 80/480 APO FPL53 Triplet OWL Series
Camera: D5300 astromodified
Reducer/flattener: Tecnosky 4 elements, 0.8x
Guide-scope: Artesky UltraGuide 60mm f/4
Guide-camera: ZWO ASI 224MC
2021/01/12: Number of subs/Exposure time: 33@300s. Notes: L-Pro filter, no Moon
2021/01/13: Number of subs/Exposure time: 33@300s. Notes: L-Pro filter, no Moon
2021/01/15: Number of subs/Exposure time: 38@300s. Notes: L-Pro filter, Moon 8% illuminated
2021/01/18: Number of subs/Exposure time: 36@300s. Notes: L-Pro filter, Moon 30% illuminated
2021/02/13: Number of subs/Exposure time: 30@300s. Notes: L-Pro filter, Moon 4% illuminated
2021/02/14: Number of subs/Exposure time: 23@300s. Notes: L-Pro filter, Moon 9% illuminated
2021/02/15: Number of subs/Exposure time: 51@14s + 48@35s. Notes: L-Pro filter, Moon 15% illuminated
2021/02/17: Number of subs/Exposure time: 11@35s + 38@180s + 1@300s. Notes: L-Pro filter, Moon 30% illuminated
Total exposure time (main integration): 65040s = 18h 04m 00s.
Total exposure time (35s integration): 2065s.
Total exposure time (14s integration): 714s.
Pre and post-processing: PixInsight 1.8.8-7.
Full HDR Version:
Masked Stretch Version:
Blended Version (50% HDR + 50% Masked Stretch):
To my personal taste, I like the blended version the most. I think it brings out the best of both worlds (HDR and soft, less contrasty but more colorful look).
I must say, I am very pleased and happy with the result. Not to boast, but I think I have come a long way since I started.
Obviously the better gear and the much, much longer integration time helped.
I think I actually spent more time post-processing it than acquiring it. Especially since I had to do the work almost twice: I post-processed the HDR and the Masked Stretch images separately, making sure I used the same processes and with the same strenght in both, so that I could combine them effectively, if I decided I didn’t like the look of the HDR alone. I also think I managed to tame the stars a lot more, compared to my previous post-processing attempts.
As usual, here’s a link to the full resolution image(s): Orion Nebula (M42), De Mairan’s Nebula (M43) and Running Man (NGC 1977)
Thanks for looking!
After many hours of fiddling round with Registax wavelet settings to process my own solar system images, I've always been curious as to how it actually works. In doing so I've put together my own image sharpening program which does something similar to Registax wavelets. For comparison, I've also added some general purpose deconvolution techniques which you'll probably be familiar with from other image processing software (like Wiener inverse filtering, Richardson-Lucy, etc). In choosing a point spread function to deconvolve with, one suprising result was that the typical stack outputs from Autostakkert work best with a Lorentz point spread function (with a minor modification). Deconvolving with a Gaussian point spread function doesn't really work. Deep-sky images seem to deconvolve best with a Moffat point spread function (which is to be expected - it's already well established that star profiles in long exposures are best approximated with a Moffat function).
On the whole, it's unlikely that you can sharpen solar system images much more in this program than you already can in Registax. You can see results from Registax wavelet (sharpening layers), inverse filtering (e.g. Wiener), and iterative deconvolution (e.g. Landweber) below. They all give very similar results. In all the techniques there's a similar trade-off between less noise but less detail vs more noise but more detail.
There are some quick start notes on the first page of the Readme here:
There are some examples of deconvolved images here (move mouse over image to see before/after):
Image credits are on the hyperlinks
The Windows download is here:
Example solar system tifs to experiment with are here:
And the project page is here (with Source code in the src folder)
If anyone finds it useful, do post here how it compares to other tools you use for solar system image sharpening.
The download and the source code are free, you can use it unrestricted for any purpose. The OpenCV and OpenCVCSharp components which my program use have licence information at the end of the Readme.pdf.
I am looking to return my Powerseeker 114eq and get a XT6. I know that my canon rebel T4i will not reach focus. It wont travel enough inwards. I want to know, which is best? Plan A is trying to use Barlow or eyepiece projection. Which will magnify less, eypiece or barlow? Are there any tips for both of tose methods and how to use eyepiece projection? Then, Plan B is moving the mirror. I cant find any good tutorials either. Thanks in advance.