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I've been less active lately in this hobby, but I've a few images done, others waiting in the pipeline to be processed.
This is a "crowded" area of our Milky Way galaxy, visible all summer from the northern hemisphere. The Cygnus constellation is home of many named and nameless nebulae.
Starting from the left (North), below the brightest star, Deneb, the Pelican and the North America Nebulae are very popular; going to right, just below the brightest star close to the center of the image, Sadr, lies the Gamma Cygni Nebula. A bit towards the top-right there's the Crescent Nebula and going forward top-right, there's the Tulip Nebula. Finally, at the bottom-right corner, the Veil Nebula, a super nova remnant.
All these are surrounded by shiny gaseous filaments or dusty patches blocking the light.
I started this during the pandemic lockdown. All of the data was captured from my hometown from a balcony brightly lit by a sodium street lamp, but the narrowband filters did their job well, blocking successfully the sodium emission.
A total of 23 hours is made of 2x3 panels composed in a larger mosaic, each panel consisting in about 1h of exposure for the red Hydrogen and 3h of exposure for the cyan Oxigen, all through a Sigma 105 macro stopped at F/4, ASI1600MMC with 6nm Astronomik filters.
I'm planning to shoot RGB data too and make an RGB/HOO composition.
Cheers and clear skies!
astrobin link: https://www.astrobin.com/r22yre/
flickr link: https://www.flickr.com/photos/170274755@N05/49939128338/
This has been a bit of a project. Last year I worked out that my 200mm Canon F2.8 lens and ASI1600 would frame the whole of the Veil complex quite nicely. I captured Ha and OIII data for the east and west nebulae with a Tak FSQ 106 and added this into the widefield image. Although the Tak data had to be shrunk down it did add a bit of extra resolution where it was needed.
The difficulty for me has been the processing. I have found it really difficult to tease out the faint wisps of detail and have tried the usual routines of micro contrast adjustments using curves along with Scott Rosen's Screen blend/mask inversion method but the results weren't great owing to the close proximity of faint and bright nebulosity. I'd heard about the PI process tool for removing stars, Starnet, so loaded this and had a rare foray into PI. This proved very helpful. It was a luminence created from Ha and OIII using the 200mm lens with the Tak data mixed in. Then the starless layer was added in PS with the screen blend mode at 50% opacity. The nebulosity detail was so well preserved I didn't need a mask. After blending I reduced the stars a bit more using the starless layer again and darken as the blend at 50%. I should really unleash some of the stars to add a bit of "punch" but I've wrestled with this data enough for now! I plan to use it further as I look deeper into the Gorgon that is PixInsight!
Telescope: Tak 106 for E and W veils. Canon 200mmL lens
Camera: ZWO ASI 1600 pro mono cmos, Gain 150, offset 50
Filters: Baader 7nm OIII and Ha
E+W Veil 10x30 mins each channel for each nebula. Whole complex 50x5mins for each channel
Captured with SGP, calibrated, aligned and combined with PI, processed mainly with PS but PI for Starnet. Ha mapped to red and OIII to both blue and green
I managed to catch a bit over an hour of RGB with the ASI071 (on Esprit 150 and Mesu200) last night before the clouds rolled in, so I could add it to my Ha data prebviously posted. Most of the RGB is 5 min exposures but I also added some 60s and 10s exposures to save Sadr - the very bright star in the centre of Cygnus and to the left in this image - it was completely blown out in the 5 min exosures. I added Ha to the red channel and I used something like a tone mapping approach (blurring out the stars of the RGB data) since the RGB stars were big, then I used Ha again as lum and I subsequently added the stars separately by selecting them in the Ha image and use the selection to cut them out of the RGB image. Sounds a bit complicated and it was. In that way I preserved the sharpness of the Ha data and kept the stars small. All done in PS of course except initial stacking and calibrating in PI. Now totally 8.8 hours.
Any comments much appreciated - I have the feeling the image could be improved but not sure how.
I had a clear night last night, but full moon of course so it had to be Ha. It gave me the first chance to test a reducer I bought from TS just when the astro-season ended this spring. SW do not sell any reducers that will work on the Esprits (the 0.85 x reducer they have for their ED pro series will not work on the Esprits according to dealers I have talked to). So the options I have managed to find are the Riccardi 0.75 reducer from APM and TS 3" 0.79x reducer. They cost about the same but after som communication with APM and TS, I realized that I would have to spend 150 - 200 Euro on adapters for the Riccardi but only needed a single one (a Lacerta M68-M86 ring for 75 Euro - which also hurts) to fit the TS reducer to the scope and it has an ordinary M48 thread on the camera side.
So here is the result from last night. 18 x 15 min on IC1318 with the Esprit 150 working at FL 840 mm (f/5.6) with a ASI1600MMpro and a 3.5 um Baader Ha filter. Seeing was not the best so guiding was around 1"/pix which will have made the image a bit soft. However, the great news are the nice star shapes in the corners. I expect the reducer will work equally well on my Esprit 100 but I have not tested it there yet (the focuser is the same so it should at least fit). Of course the ASI1600 gave the expected microlensing effect around the bright gamma-cygnus.
Next clear night I will make a second panel to the left of the image to produce a "panorama" mosaic.
Only stretched - nothing else so far, not even any darks or flats.