u/fieryserpents01

I might be more than 20 reprocesses deep into this nebula at this point. I just know that my first attempt looked like this.

I found that processing this nebula with my very limited skills is way harder than I imagined as it presented several challenges, namely keeping the core under control while maintaining the color as natural as possible, bringing the surrounding nebulosity up and teasing as much detail from both the dusty surroundings and the object itself.

At some point I also discovered that I managed to capture some faint blue hues in the core and I had to try to bring them out in the final image! To do that I used color preserving stretches only.

I'm sure I'll come back to this eventually, but I can say I am sort of satisfied for now.

Acquisition:

Around 7h30m worth of 60s subs in Bortle 6/7 fully calibrated and dithered.

Equipment:

Evostar 72ED, iEXOS 100, ASI 533MC, Baader UV/IR cut, 0.85x reducer+flattener, rotator+filter holder, SVBony 40mm F/4 guidescope, ASI 662MC guide camera with pale yellow no.8 and UV/IR cut filters.

Processing details:

Drizzle preprocessing and stacking in Siril at 1x scale and gaussian model. Perform first SPCC. Split into channels, background extraction to each in GraXpert. Recombine and second SPCC in Siril (average spiral galaxy). Deconvolution. First denoise in GraXpert. Generate starless image and star mask in Siril. Black point shift, asinh as the first stretch, light GHS with selection to faint nebulosity with black point shift and light inverse GHS to dark lanes iteratively all with human weighted luminance. Second noise reduction in GraXpert. À trous wavelets transform to higher layers in Siril along with a further stretch selected to fainter nebulosity and SCNR. Desaturate in Siril. Slight color balance adjustments in Gimp. Further stretches to brighter surroundings and main nebulosity in Siril.

Open star mask, asinh, SCNR and unpurple filter. Recombine and final black point shifts.

Acquisition:

Around 9h30m worth of 60s subs fully calibrated and dithered in Bortle 6/7. The dew point hasn't gone below 23°C at night for weeks now.

I have to thank u/ZigZagZebraz for helping me take decent flats for the first time in my life.

The framing isn't the best but my rotator (Skywatcher original) introduces lots of tilt in the imaging train if I'm not careful, so I'm using it as a filter holder only and I have to be quick to set up because my power station lasts only a few hours. I'm thankful the sensor is square.

Equipment:

Evostar 72ED, iEXOS 100, ASI 533MC, 0.85x reducer+flattener, Baader UV/IR cut, SVBony 40mm F/4 guidescope and ASI 662MC guide camera with UV/IR cut and no.8 pale yellow filters.

Processing:

OSC drizzle preprocessing and stacking in Siril with gaussian droplet model. Stacked in Siril. Background extraction in GraXpert. G2V star SPCC and deconvolution in Siril. Open GraXpert again, denoise. Open Siril, generate starless and star mask. GHS, curve adjustments and black point shift applied iteratively to the starless image. Open GraXpert again, denoise stretched image. Go back to Siril, SCNR, cosmetic correction and mild median filter to reduce denoising artifacts. BSpline À trous wavelets transform to higher layers, final black point adjustments and saturation stretch.

Asinh stretch to star mask, mild GraXpert denoising, SCNR and unpurple filter. Recombine.

Yet another reprocess (the 10th if not more) of the same data I took more than a month ago.

Acquisition:

Around 7h30m in Bortle 6/7 fully calibrated and dithered.

Equipment:

Evostar 72ED, iEXOS 100, ASI 533MC, 0.85x reducer+flattener, Baader UV/IR cut, SVBony 40mm F/4 guidescope, ASI 662MC guide camera with no.8 pale yellow and UV/IR cut filters.

Processing:

Stacked in Siril. Background extraction to single channels in GraXpert. SPCC. Deconvolution in Siril, denoising back in GraXpert. Back to Siril to apply SCNR and to generate a starless image and a star mask. GHS, black point shift, curve adjustments and histogram transformation applied iteratively to the image. À trous wavelet transform and further denoising in GraXpert. Final saturation stretch in Siril. Asinh and black point shift applied to the star mask along with a saturation stretch. Recombine.

I'll definitely come back to this to reprocess it.

This image was plagued with issues from the start. First I spent a whole night, one of the best ones seeing and transparency wise, pointing toward the wrong part of the sky... Turns out there are TWO stars named 11 Sagittarii close to each other. My fault for not triple checking the plate solver.

Next, I spent a whole week acquiring data battling dew points up to 25 °C, clouds and an uncooperative mount. I had to update its firmware, but that threw the whole driver setup I had off. iEXOS mounts are so finicky. That made me learn how to use Nina's plate solver once and for all though. Not only that, I also had to open up the mount ten or more times in a week because its gears were too tight and because of a minuscule piece of grit stuck, it turned out, in the motor's gear that caused some huge guide spikes. I also redesigned my DIY counterweight to have it as close to the mount as possible while being east heavy.

Lastly, I realized I have noticeable sensor tilt, which is the main cause of the gradient I always find in my raw images (the sensor isn't square to the UV/IR cut). I can remove it with flats, but I also realized my flats weren't optimal, which occasionally creates huge artifacts that are tough to remove; plus I realized that my rotator can introduce some pretty bad tilt into the optical train if I'm not careful.

Acquisition:

Around 12h30m worth of 60s subs in Bortle 6/7 fully calibrated and dithered.

Equipment:

Evostar 72ED, iEXOS 100, ASI 533MC, Baader UV/IR cut filter, 0.85x reducer+flattener, SVBony 40/160 guidescope, ASI 662MC guide camera with no.8 pale yellow and UV/IR cut filters.

Processing:

Stacked in Siril. For some reason OSC drizzle registration causes some weird artifacts to my stars and some odd photometry results. If anyone has any suggestions, they're more than welcome. Split image into CFA channels, background extraction to each in GraXpert to deal with the gradient. Open Siril, recombine CFA channels and deconvolution. Open GraXpert, denoise. Open Siril, generate starless and star mask. Apply black point shift and GHS iteratively to the starless image to bring out various parts of the nebulosity, SNCR, minor curve adjustments, median filter, VST noise reduction and à trous wavelet transform plus some final denoising in GraXpert. Asinh stretch to starless and saturation boost in Gimp. Recombine and export.

This is a reprocess of data I took a month ago.

Acquisition:

Around 7h20m worth of 60s subs in Bortle 6/7, fully calibrated and dithered.

Equipment:

Evostar 72ED, iEXOS 100, ASI 533MC, 0.85x reducer+flattener, Baader UV/IR cut, SVBony 40/160 guidescope, ASI 662MC guide camera with no.8 pale yellow and UV/IR cut filters.

Processing:

Stacked in Siril. SPCC. Background extraction in GraXpert. Back to Siril, deconvolution. Back to GraXpert, denoise. Open Siril, generate starless and star mask. GHS and black point shift to starless, SCNR, curve adjustments, mild VST denoise and median filter, à trous wavelet transform to higher layers and final denoising in GraXpert. Open star mask, asinh stretch, saturation boost and small curve adjustments. Recombine.

Acquisition:

Around 7h10m worth of 60s subs in Bortle 6/7 fully calibrated and dithered.

Equipment:

Evostar 72ED, iEXOS 100, ASI 533MC, Baader UV/IR cut, 0.85x reducer+flattener, SVBony 40/160 guidescope, ASI 662MC guide camera with no.8 pale yellow and UV/IR cut filters.

Processing:

Stacked in Siril. Perform SPCC. Open GraXpert, background extraction. Open Siril, deconvolution. Open GraXpert, denoise. Open Siril, generate starless and star mask. GHS, and black point shift to starless. Histogram transformation and SCNR to balance out residual cast, curve adjustments, VST noise reduction, median filter, à trous wavelet transform to higher layers. Open GraXpert, denoise. Open star mask, asinh stretch and black point shift, saturation boost. Recombine and final black point adjustments.

This is a reprocess of the image I took a couple of weeks ago. I realized that I took my bias and dark frames with a different white balance and that was messing with my data resulting in tons of nasty gradients.

Acquisition:

Around 7h30m worth of 60s subs in Bortle 6/7 fully calibrated and dithered.

Equipment:

Evostar 72ED, iEXOS 100, ASI 533MC, Baader UV/IR cut, 0.85x reducer+flattener, SVBony 40/160 guidescope, ASI 662MC guide camera with no.8 pale yellow and UV/IR cut filters.

Processing:

Stacked in Siril. Apply SPCC. Open GraXpert, crop and background extraction. Open Siril, deconvolution. Open GraXpert, denoise. Open Siril, generate starless and starmask. Black point shift and GHS to starless, histogram transformation to tame residual color cast, curve adjustments to accentuate contrast between features plus SCNR. Mild VST denoise and median filter. À trous wavelet transform to higher layers. Open GraXpert, denoise. Open Siril, Asinh stretch and saturation boost to stars. Recombine starless and starmask.

Acquisition:

Around 8h20m worth of 60s subs in Bortle 6/7, fully calibrated and dithered every 10 frames.

Equipment:

Evostar 72ED, IEXOS 100, ASI 533MC, 0.85x reducer+flattener, Baader UV/IR cut, 40/160 SVBony guidescope, ASI 662MC guide camera with no.8 pale yellow and UV/IR cut filters.

Processing:

Open Siril to calibrate and stack. Apply SPCC. Open GraXpert, crop and apply background extraction. Open Siril, deconvolution. Open GraXpert, denoise. Open Siril, generate starless and star mask. GHS to starless, histogram adjustments to tame residual gradients, further stretch and black point adjustments, curve adjustments, light Siril denoise and median Filter, further light stretches and curve adjustments plus SCNR. Mild à trous wavelet transform on higher layers. Open GraXpert, denoise. Open Siril, final black point adjustments.

Open starmask, apply asinh stretch and saturation boost, recombine.

Acquisition: around 8h20m worth of 60s subs fully calibrated in Bortle 6/7, dithered every 10 frames.

Equipment: Evostar 72ED, iEXOS 100, ASI 533MC, Baader UV/IR cut, 0.85x reducer+flattener, SVBony 40/160 guidescope, ASI 662MC with UV/IR cut and no.8 pale yellow filter.

Processing: Stacked in Siril. First cropping and SPCC in Siril. Background extraction in GraXpert. I used the AI model because of very nasty gradients, I couldn't get it to work with RBF; this object doesn't rise much at my latitude. Open Siril again, further SPCC, deconvolution, noise reduction, mild median filter, generate starless and starmask. Black point shift and GHS applied iteratively to starless, histogram transformation, mild curve adjustments, SCNR, mild à trous wavelet transform sharpening, further mild noise reduction. Asinh stretch and saturation boost to starmask.

Acquisition: around 9h50m worth of 60s subs in Bortle 6/7, fully calibrated and dithered every 10 frames.

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Equipment: Evostar 72ED, IEXOS 100, ASI 533MC, Baader UV/IR cut, 0.85 reducer+flattener, SVBony 40/160 guidescope, ASI 662MC with pale yellow no.8 and UV/IR cut filters guide camera.

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Processing: stacked in Siril. SPCC, background extraction in GraXpert, further background adjustments in Siril, further SPCC, deconvolution, noise reduction, black point stretch, create starless image and star mask. Human weighted luminance GHS and black point stretch iteratively, curve and histogram adjustments, SCNR and median filter for starless. Asinh stretch and saturation adjustments for star mask. Mild sharpening and median filter for recombined image.

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Acquisition: around 6h20m worth of 60s subs gain 105 in Bortle 6/7. Dithered every 10 frames. Calibrated with 30 darks, flats and bias frames.

Equipment: Evostar 72ED, IEXOS 100, ASI 533MC, UV/IR cut, 0.85x reducer+flattener, 40/160mm SVBony guidescope, ASI 662MC guide camera with no. 8 pale yellow and UV/IR cut filters.

Processing: stacking and SPCC in Siril. Background extraction in GraXpert. Back to Siril: further SPCC, noise reduction, black point shift and generate starless image and star mask. GHS, black point and curve adjustments to starless. Asinh in Siril and saturation boost in Gimp to star mask. Recombine images, further black point adjustments, median filter and SCNR. Tried chrominance noise reduction to starless in Gimp but didn't like the way it looked.

Around 4h30m in Bortle 6/7, 60s frames, dithered every 10 frames.

Evostar 72ED, IEXOS 100, ASI 533MC, UV/IR cut, 0.85x reducer, SVBony 40/160 guidescope, ASI 662MC guide camera with no.8 pale yellow and UV/IR cut filters.

Stacked in Siril. Background extraction, denoising, photometric color calibration, general stretching, green noise removal and curve adjustments performed in Siril. Unsharp mask and color saturation adjustments in Gimp.

Around 4h30m in Bortle 6/7, 60s frames, dithered every 10 frames.

Evostar 72ED, IEXOS 100, ASI 533MC, UV/IR cut, SVBony 40/160 guidescope, 0.85x reducer, ASI 662MC guide camera with no.8 pale yellow and UV/IR cut filters.

Stacked in Siril. Background extraction, denoising, photometric color calibration, general stretching, green noise removal and curve adjustments performed in Siril. Unsharp mask and color saturation adjustments in Gimp.

Around 4h30m fully calibrated in Bortle 7 with a full Moon.

Equipment used: Evostar 72ED, IEXOS 100, ASI 533MC, UV/IR cut, 0.85x reducer+flattener, SVBony 40/160 guidescope, ASI 662MC with a pale yellow filter and UV/IR cut.

Processing: Background extraction to sequence and to the final stack, green noise reduction, denoising, SPCC, stretching, curve adjustments, saturation adjustments, edge preserving filter in Siril. Chrominance noise reduction in Gimp.

I struggled with a pretty bad gradient most likely caused by the Moon.

First light with my new equipment.

Around 9h30m in 60s subs in Bortle 6/7 close to a full Moon. Stacked and processed in Siril (denoising, background extraction, spectrometric color calibration; general stretching, cropping and sharpening).

Equipment used: Evostar 72ED, IEXOS 100, ASI 533MC, 0.85 flattener+reducer, UV/IR cut, SVBony 40/160 guidescope and ASI 662MC with UV/IR cut and pale yellow filters.