Finally, after about a year, I started shooting the sky again and spending time with the telescope admiring the wonders of the universe.
My telescope was intended for visual use, at the beginning I was a visualist, but I soon realized that I needed to see what our eye cannot admire, so I tried to optimize it for astrophotography. The good mechanical characteristics and the excellent optical correction allowed me to obtain good results as it was, although the instrument was not born for that purpose, but as often happens I wanted more maintaining the 60 cm diameter. So the only solution, at least for now, has been to try to improve the instrumentation to make it as suitable as possible for producing images.
So in the last year a journey has begun in which I have improved the structure of my instrument in order to be able to accommodate a heavy optical train, consisting of a full frame camera and its relative corrector, without incompatible bending with good results. I have to thank my dear friend and mentor Marco Lorenzi, as always, for his extreme competence, the manufacturer Nauris.de for the replacement of some components, and Astrottica in helping me choose the most suitable products.
This image is the first light of this new setup. This is a crop. The C version is the full frame format.
It all started in Forca Canapine during the last new Moon, with my dear friend Lorenzo Burti. We spent a night together with other experienced amateur astronomers, observing through incredible instruments and enjoying the starry sky. I spent the next five days traveling through central Italy looking for the best conditions to collect data and produce this image, while my wife, whom I will never stop thanking, ran the things at home, giving me time to play… The first two nights were wasted collecting luminance because I believed that nothing good would come out in narrow band, realizing later that the large diameter allowed instead to collect sufficient information even in narrow band despite very short exposures, so I continued with the idea of composing a trichrome HOO and RGB for the stars, thus not using the first two nights of luminance. It would have been much more useful to increase the narrowband signal rather than in luminance but that's how it happened, hoping to integrate, especially in OIII, in the future. In the same days the incredible tool, Fast Integration by PixInsight, was published, so what better opportunity than to feed it my approximately 20.000 frames to squeeze it to the max! And so it was. Personally I'm very happy with how this tool works even if it needs to be slightly optimized which surely, if the tool were to become commonly used among users, will be done considering the great competence of the developers.
Some post-processing information:
- The OIII signal in the extensions was clearly evident but faint; to emphasize it I applied a selective stretch creating a mask from the same OIII image using the Range Selection tool with which I first increased the signal to make the extensions well represented and then I eliminated the saturated central parts by reducing the Upper limit, and finally I blurred and softened the mask by increasing Fuzziness and Smoothness, which also eliminated the background noise;
- The stars spikes look quite messy. This is typical of altazimuthal instruments in which even with the use of the derotator the field derotates but the spikes do not, therefore the various channels have misaligned spikes. I am personally happy with that.
I hope you like it.
Nauris Mirrage Dobsonian Telescope 600mm f3,8
http://nauris.de/index.php/en/telescopes/vates-astrographStellarCAT - Nexus DSC
Astronomik 50 mm round unmounted LRGB MaxFR Ha OIII SII
Big Paracorr 3" type2 Coma Corrector
Feather Touch True 3" Focuser
Falcon Pegasus Astro derotator
SharpCap (Smart Histogram) - PixInsight (Fast Integration) - SiriL - PhotoShop
OIII 6000 x 2 sec. Gain 400 -10° Bin 1x1
Ha 6000 x 2 sec. Gain 400 -10° Bin 1x1
L 9000 x 2 sec. Gain 350 -10° Bin 1x1
R-G-B 1200 x 2 sec. Gain 400 -10° Bin 2x2
Comments