Not to self promote my own community too much, but !astrophotography@lemmy.world if you wanna see amateur photos of space
Decided to just shoot a semi-random part of Cygnus. The large extended Ha region in Cygnus is unofficially called Smaug, and this is a photo specifically of the area around LBN 325/326. The nebulosity in this pic is false color, but the stars are true color RGB. I really love how this turned out with the narrowband palette, especially with the Oiii region on the right side looking almost like a true color Ha region. Captured over a shitload of nights from Aug-Oct 2024 from a bortle 9 zone.
Places where I host my other images:
TPO 6" F/4 Imaging Newtonian
Orion Sirius EQ-G
ZWO ASI1600MM-Pro
Skywatcher Quattro Coma Corrector
ZWO EFW 8x1.25"/31mm
Astronomik LRGB+CLS Filters- 31mm
Astrodon 31mm Ha 5nm, Oiii 3nm, Sii 5nm
Agena 50mm Deluxe Straight-Through Guide Scope
ZWO ASI-290mc for guiding
Moonlite Autofocuser
Acquisition: 57 hours 40 minutes (Camera at -15°C), NB exposures at unity gain and BB at half unity
Ha - 111x600"
Oiii - 127x600"
Sii - 94x600"
R - 48x60"
G - 48x60"
B - 44x60"
Darks- 30
Flats- 30 per filter
Capture Software:
PixInsight Preprocessing:
BatchPreProcessing
StarAlignment
Blink
ImageIntegration per channel
DrizzleIntegration (2x, Var β=1.5)
Dynamic Crop
DynamicBackgroundExtraction
duplicated each image and removed stars via StarXterminator. Ran DBE with a shitload of points to generate background model. model subtracted from original pic using the following PixelMath (math courtesy of /u/jimmythechicken1)
$T * med(model) / model
Narrowband Linear:
Blur and NoiseXTerminator
StarXterminator to completely remove stars (to be later replaced by the RGB ones)
HistogramTransformation to stretch nonlinear
RGB Linear:
ChannelCombination to combine monochrome R G and B frame into color image
SpectroPhotometricColorCalibration
BlurXTerminator for star sharpening (correct only)
HSV Repair
StarXterminator to generate a stars-only image
ArcsinhStretch + HT to stretch nonlinear (to be combined with starless narrowband image later)
Invert > SCNR > invert to remove magentas
Curves to saturate the stars a bit more
Nonlinear:
R = 0.3*Oiii+0.7*(Oiii^~(0.7*Ha+0.3*Sii))^1.2
G = ((Oiii*Ha)^~(Oiii*Ha))*Ha + ((Oiii*Ha)^(Oiii*Ha))*Sii
B = 0.9*Sii+Ha-Oii
NoiseX again
Shitloads of Curve Transformations to adjust lightness, hues, contrast, saturation, etc
more curves
Extract L --> LRGBCombination for chrominance noise reduction
even more curves
Pixelmath to add in the stretched RGB stars only image from earlier
This basically re-linearizes the two images, adds them together, and then stretches them back to before. More info on it here)
mtf(.005,
mtf(.995,Stars)+
mtf(.995,Starless))
Couple final curves
Resample to 60%
Annotation
Decided to just shoot a semi-random part of Cygnus. The large extended Ha region in Cygnus is unofficially called Smaug, and this is a photo specifically of the area around LBN 325/326. The nebulosity in this pic is false color, but the stars are true color RGB. I really love how this turned out with the narrowband palette, especially with the Oiii region on the right side looking almost like a true color Ha region. Captured over a shitload of nights from Aug-Oct 2024 from a bortle 9 zone.
Places where I host my other images:
TPO 6" F/4 Imaging Newtonian
Orion Sirius EQ-G
ZWO ASI1600MM-Pro
Skywatcher Quattro Coma Corrector
ZWO EFW 8x1.25"/31mm
Astronomik LRGB+CLS Filters- 31mm
Astrodon 31mm Ha 5nm, Oiii 3nm, Sii 5nm
Agena 50mm Deluxe Straight-Through Guide Scope
ZWO ASI-290mc for guiding
Moonlite Autofocuser
Acquisition: 57 hours 40 minutes (Camera at -15°C), NB exposures at unity gain and BB at half unity
Ha - 111x600"
Oiii - 127x600"
Sii - 94x600"
R - 48x60"
G - 48x60"
B - 44x60"
Darks- 30
Flats- 30 per filter
Capture Software:
PixInsight Preprocessing:
BatchPreProcessing
StarAlignment
Blink
ImageIntegration per channel
DrizzleIntegration (2x, Var β=1.5)
Dynamic Crop
DynamicBackgroundExtraction
duplicated each image and removed stars via StarXterminator. Ran DBE with a shitload of points to generate background model. model subtracted from original pic using the following PixelMath (math courtesy of /u/jimmythechicken1)
$T * med(model) / model
Narrowband Linear:
Blur and NoiseXTerminator
StarXterminator to completely remove stars (to be later replaced by the RGB ones)
HistogramTransformation to stretch nonlinear
RGB Linear:
ChannelCombination to combine monochrome R G and B frame into color image
SpectroPhotometricColorCalibration
BlurXTerminator for star sharpening (correct only)
HSV Repair
StarXterminator to generate a stars-only image
ArcsinhStretch + HT to stretch nonlinear (to be combined with starless narrowband image later)
Invert > SCNR > invert to remove magentas
Curves to saturate the stars a bit more
Nonlinear:
R = 0.3*Oiii+0.7*(Oiii^~(0.7*Ha+0.3*Sii))^1.2
G = ((Oiii*Ha)^~(Oiii*Ha))*Ha + ((Oiii*Ha)^(Oiii*Ha))*Sii
B = 0.9*Sii+Ha-Oii
NoiseX again
Shitloads of Curve Transformations to adjust lightness, hues, contrast, saturation, etc
more curves
Extract L --> LRGBCombination for chrominance noise reduction
even more curves
Pixelmath to add in the stretched RGB stars only image from earlier
This basically re-linearizes the two images, adds them together, and then stretches them back to before. More info on it here)
mtf(.005,
mtf(.995,Stars)+
mtf(.995,Starless))
Couple final curves
Resample to 60%
Annotation
0, I’m just raw dogging /all (minus whomever .world is defederated from)
Med student here. I probably would’ve failed a lot of in house exams/step 1 if I didn’t use anki. IMO it’s best for solidifying knowledge and quick recall of facts, but doing a shitload of practice questions is the best way to apply what you’ve memorized through anki (this last bit is most applicable to med school/mcat prep).
Really the main cost with it is your time. If you miss a day or two it can be daunting to get back in the groove and work on your review backlog. I usually have enough downtime during the day and time on the shitter to get through my reviews + whatever new cards I add. Anki itself is free but they do have a paid iOS app that I got just to use whenever I had a few mins of spare time.
As for the learning curve, this will vary if you’re making your own cards vs using a premade deck for a large standardized exam. Once you know the formatting it isn’t that difficult to make cloze cards for what you’re trying to learn.
The starliner astronauts are still up there (and will be until they return on the crew 9 capsule in February). This is the crew that went up before them returning to earth
What did you use to capture/process this?
Love the colors!
Holy fuck they did it
He’s just a skeegy little guy
Mildew is ‘eepin
Got the flu and had to cancel my birthday movie party. Most of my friends went to go see the movie anyway. It was the Bee Movie
That shot of the forward thrusters is great!
What focal length do you normally shoot at? My rig is at 610mm and I get satellite trails mostly around dusk/dawn, but they all get rejected out during stacking
Some nice colors in the sky If you’re north enough. Sadly I doubt this will be as strong as the aurora back in May, but maybe one day well get them down in Atlanta again
NGC 4490 is a galaxy colliding with the smaller NGC 4485 galaxy, and both are about 25 million light years away. This image was taken with a monochrome camera through filters for luminance (all visible light), red, green, blue, and Hydrogen-alpha (656nm), which were combined into a color image. The Hydrogen-alpha was combined with red (described below) to make the HaLRGB image. The pink Ha regions are star forming nebulae within the galaxies. This got cropped out of the final pic, but I ended getting some gorgeous diffraction spikes on this star near the edge of the full FOV
Places where I host my other images:
TPO 6" F/4 Imaging Newtonian
Orion Sirius EQ-G
ZWO ASI1600MM-Pro
Skywatcher Quattro Coma Corrector
ZWO EFW 8x1.25"/31mm
Astronomik LRGB+CLS Filters- 31mm
Astrodon 31mm Ha 5nm, Oiii 3nm, Sii 5nm
Agena 50mm Deluxe Straight-Through Guide Scope
ZWO ASI-120MC for guiding
Moonlite Autofocuser
Acquisition: 27 hours 37 minutes (Camera at half Unity Gain, -15°C)
Ha - 128x360"
Lum - 464x60"
Red - 152x60"
Green - 150x60"
Blue - 123x60"
Flats- 30 per filter
24 JimmyFlats per broadband filter
Capture Software:
PixInsight Processing:
BatchPreProcessing (with premade JimmyFlats)
StarAlignment
ImageIntegration
DrizzleIntegration (2x, Var β=1.5)
DynamicCrop
DynamicBackgroundExtraction
duplicated each image and removed stars via StarXterminator. Ran DBE to generate background model. model subtracted from original pic using the following PixelMath (math courtesy of /u/jimmythechicken1)
$T * med(model) / model
Luminance:
BlurXTerminator
ArcsinhStretch + histogramtransformation to bring nonlinear
RGB:
ChannelCombinaiton to combine monochrome R, G, B stacks into color image
SpectroPhotometricColorCalibration
BlurXTerminator (correct only mode)
HSV Repair
making clean Ha
loosely following this guide
This basically subtracts any broadband signal from the Ha pic, leaving only the Ha emission, which is then combined in with the red and a little bit of the blue channels
Ha-Q * (Red-med (Red)), Q=0.75
Red = $T+B*(Ha_Clean - med(Ha_Clean))
Green = $T
Blue = $T+B0.2(Ha_Clean - med(Ha_Clean))
B variable = 0.6 (this controls how strongly the Ha is added)
Nonlinear
ArcsinhStretch + histogramtransformation to bring HaRGB image nonlinear
MLT for large scale chrominance noise reduction
shitloads of curve transformations to adjust lightness, contrast, saturation, etc (with various luminance and star masks)
slight SCNR to remove some greens
LRGBCombination with stretched Luminance
DeepSNR
more curves
ColorSaturation to slightly desaturate the Ha regions (they were very pink compared to the rest of the galaxy
slight noisexterminator
LocalHistogramEqualization
even more curves
Resample to 75%
DynamicCrop onto just the galaxy
annotation
NGC 4490 is a galaxy colliding with the smaller NGC 4485 galaxy, and both are about 25 million light years away. This image was taken with a monochrome camera through filters for luminance (all visible light), red, green, blue, and Hydrogen-alpha (656nm), which were combined into a color image. The Hydrogen-alpha was combined with red (described below) to make the HaLRGB image. The pink Ha regions are star forming nebulae within the galaxies. This got cropped out of the final pic, but I ended getting some gorgeous diffraction spikes on this star near the edge of the full FOV
Places where I host my other images:
TPO 6" F/4 Imaging Newtonian
Orion Sirius EQ-G
ZWO ASI1600MM-Pro
Skywatcher Quattro Coma Corrector
ZWO EFW 8x1.25"/31mm
Astronomik LRGB+CLS Filters- 31mm
Astrodon 31mm Ha 5nm, Oiii 3nm, Sii 5nm
Agena 50mm Deluxe Straight-Through Guide Scope
ZWO ASI-120MC for guiding
Moonlite Autofocuser
Acquisition: 27 hours 37 minutes (Camera at half Unity Gain, -15°C)
Ha - 128x360"
Lum - 464x60"
Red - 152x60"
Green - 150x60"
Blue - 123x60"
Flats- 30 per filter
24 JimmyFlats per broadband filter
Capture Software:
PixInsight Processing:
BatchPreProcessing (with premade JimmyFlats)
StarAlignment
ImageIntegration
DrizzleIntegration (2x, Var β=1.5)
DynamicCrop
DynamicBackgroundExtraction
duplicated each image and removed stars via StarXterminator. Ran DBE to generate background model. model subtracted from original pic using the following PixelMath (math courtesy of /u/jimmythechicken1)
$T * med(model) / model
Luminance:
BlurXTerminator
ArcsinhStretch + histogramtransformation to bring nonlinear
RGB:
ChannelCombinaiton to combine monochrome R, G, B stacks into color image
SpectroPhotometricColorCalibration
BlurXTerminator (correct only mode)
HSV Repair
making clean Ha
loosely following this guide
This basically subtracts any broadband signal from the Ha pic, leaving only the Ha emission, which is then combined in with the red and a little bit of the blue channels
Ha-Q * (Red-med (Red)), Q=0.75
Red = $T+B*(Ha_Clean - med(Ha_Clean))
Green = $T
Blue = $T+B0.2(Ha_Clean - med(Ha_Clean))
B variable = 0.6 (this controls how strongly the Ha is added)
Nonlinear
ArcsinhStretch + histogramtransformation to bring HaRGB image nonlinear
MLT for large scale chrominance noise reduction
shitloads of curve transformations to adjust lightness, contrast, saturation, etc (with various luminance and star masks)
slight SCNR to remove some greens
LRGBCombination with stretched Luminance
DeepSNR
more curves
ColorSaturation to slightly desaturate the Ha regions (they were very pink compared to the rest of the galaxy
slight noisexterminator
LocalHistogramEqualization
even more curves
Resample to 75%
DynamicCrop onto just the galaxy
annotation
It’s an artifact from the camera. The ASI1600 has microlenses over each pixel on the sensor, which makes this pattern around bright stars
The Horsehead Nebula is a dark nebula about 1400ly away from us in the constellation Orion. The Bright star near it is Alnitak, and it one of the stars that makes up Orion’s Belt. Because this is one of the brightest stars that people photograph when shooting DSOs, it often can result in unwanted halos, which are present in my RGB filters. I was able to edit the halos out to a level I felt was acceptable (see processing info below), however there still is some color fringing/artifacts on the edge of the halos. Also the bottom left of Alnitak is the Flame Nebula, which is just a nebula that happens to be in the foreground to the horsehead. Captured over 5 nights from February 14-20, 2022 from my Bortle 6 driveway.
Places where I host my other images:
TPO 6" F/4 Imaging Newtonian
Orion Sirius EQ-G
ZWO ASI1600MM-Pro
Skywatcher Quattro Coma Corrector
ZWO EFW 8x1.25"/31mm
Astronomik LRGB+CLS Filters- 31mm
Astrodon 31mm Ha 5nm, Oiii 3nm, Sii 5nm
Agena 50mm Deluxe Straight-Through Guide Scope
ZWO ASI-120mc for guiding
Moonlite Autofocuser
Acquisition: 12 hours 6 minutes (Camera at Unity Gain, -20°C)
Lum- 251x60"
Ha- 67x300"
Red- 33x90"
Green- 31x60"
Blue- 29x60"
Darks- 30
Flats- 30 per filter
Capture Software:
PixInsight Processing:
BatchPreProcessing
SubframeSelector
StarAlignment
ImageIntegration
DrizzleIntegration (2x, Var β=1.5)
Linear:
DynamicCrop
Automatic and Dynamic Background extractions
RGB:
ChannelCombination to map monochrome R, G, and B images into a color image
PhotometricColorCalibration
Slight SCNR green
HSV repair
ArcsinhStretch + HistogramTransformation to bring nonlinear
Luminance:
0.7*Ha + 0.3*Lum
EZ Decon
NoiseXTerminator
ArcsinhStretch + HistogramTransformation to bring nonlinear
Nonlinear:
Created two circle masks per this guide. SCNR + curve tweaks to mitigate the halos from my RGB filters
LRGBCombination with SuperLum
Ungodly amounts of curve transformations to further mitigate the halos, as well as just general curves for lightness, saturation, contrast, hues, etc.
ColorSaturation
Extract L > LRGBCombination for chrominance noise reduction
LocalHistogramEqualization
EZ Star reduction
NoiseGenerator to add noise into reduced star areas
another round of LHE
more curves
CloneStamp to remove a couple of weirdly artifacted stars
even more curves
Resample to 60%
Annotation
no effort november my beloved