I took advantage of some clear Winter nights in late June with a new moon to capture M16 Eagle Nebula with my 2600MM for the first time under B8 skies in Sydney. I’ve previously imaged this target many times before with my 2600MC OSC and prior to that with my DSLR nearly 9 years ago.*
The only disappointing part of this project was that I must have re tightened the focuser on the side thumbscrew between one of the filters on one night ?? This caused my TS GPU Coma*corrector to tilt slighting on one side in the optical plane causing each filters Star field to be slightly out of alignment on the LHS of the FOV when composing an SHO image. The tiny faint stars in*the LH corners and towards the centre were double stars touching each other. The medium and larger stars were affected as well but not as severe. The stars in each processed image ( Ha , Oiii and Sii ) for each filter data set on their own were perfect , pin point to edge of field. But combine them or compose them in an SHO composite and you have this star anomaly. Very frustrating to say the least. I need to be mindful about touching the side thumbscrew on the focuser.
Anyway I decided not to waste the quality data so processed them as normal and cropped out quite a bit of the LHS perimeter plus used the “Heal module” in Startools to remove or hide most of the double stars to produce a type of semi Starless image with just larger stars and faint tiny stars.**Not ideal but at least it’s not a disaster and a waist of clear sky time. I’m not a real fan of starless images so tried to retain as many of the unaffected larger stars and tiny faint ones. The rest were horrible.
It does prove one thing this TS GPU coma corrector is a quality bit of kit as all three filter data sets when processed individually had pin point stars to edge of frame , even though the corrector wasn’t sitting perfectly level with the optical
plane. It did its job !!
Bortle 8 City Suburban location
New Moon period*
Seeing conditions variable over the 4 nights*( windy , heavy dew , dry )
Telescope 8” f5 Klaus Helmerich Carbon Fibre Newtonian ( Self Built )*focal length 1050mm
Mount Skywatcher EQ6-R Pro*
Imaging camera ZWO2600MM cooled to -10C , Gain 100 HCG*
TS Optics GPU coma corrector with Beamtech 15mm spacing ring
Antlia 3nm filters*
PHD2 Multistar guiding ( variable 0.40 to 0.50 arc sec and 0.70 to 0.80 arc sec total on different nights)
Orion 60mm guide scope with helical focuser*
ZWO EFW 7 x 2”*
ZWO EAF focuser*
Tracking and Goto EQMOD and Stellarium*
Aquisition and Capture , APT*
Ha 137 x 2 min dithered subs*
Oiii 141*x 2 min dithered subs
Sii 147 x 2 min dithered subs
Full Calibration Suite*
Darks from Library*
Flats for Ha , Oiii and Sii
Flat Darks for Ha , Oiii and Sii
Total integration 14 hours*
Subs reviewed in ASTAP*
Subs analysed, calibrated , stacked and aligned in ASTAP*
Post processed in Startools version 1.8 via Compose module*using Luminance / Color :**L + Synthetic L from RGB , RGB.
Used an SHO preset in the Colour module and adjusted to taste.*
Astrobin links for full resolution…..,
https://www.astrobin.com/full/p7fe51/0/
https://www.astrobin.com/full/464tf6/0/
https://www.astrobin.com/full/mw9u39/0/
Attached images in IIS 200Kb
NB: These images are presented as documentary astrophotography and have not use any AI enhanced or AI assisted technology during post processing.
Thanks for Looking
Comments most welcome*
Martin
Then, also, there is certainly some good feature detail showing for sure, eg. in that main pillar, many of the main famous fine features can be discerned, so that's great. For me though, there is a certain embossed look to many of the features/details across the image, particularly evident in the top left area, those wiggly dust lanes don't look quite natural..
? I imagine this has resulted from the method of application of decon/sharpening? I also feel that some extra contrast introduced across the image would lift it too.
