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:

Flickr | Instagram

Equipment:

• 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:

• Captured using N.I.N.A. and PHD2 for guiding and dithering.

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:

• PixelMath to combine monochrome Ha Oiii and Sii images into a color image with Jimmy’s Royale Palette

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:

Flickr | Instagram

Equipment:

• 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:

• Captured using N.I.N.A. and PHD2 for guiding and dithering.

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:

• PixelMath to combine monochrome Ha Oiii and Sii images into a color image with Jimmy’s Royale Palette

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

Guess I’ll be sticking with mine for a little bit longer. Was really hoping for pancake lenses in this

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:

Flickr | Instagram

Equipment:

• 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:

• Captured using N.I.N.A.

PixInsight Processing:

• BatchPreProcessing (with premade JimmyFlats)

• StarAlignment

• Blink

• 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

• PixelMath to isolate just Ha

Ha-Q * (Red-med (Red)), Q=0.75

• PixelMath to add Ha into RGB image

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:

Flickr | Instagram

Equipment:

• 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:

• Captured using N.I.N.A.

PixInsight Processing:

• BatchPreProcessing (with premade JimmyFlats)

• StarAlignment

• Blink

• 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

• PixelMath to isolate just Ha

Ha-Q * (Red-med (Red)), Q=0.75

• PixelMath to add Ha into RGB image

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:

Instagram | Flickr

Equipment:

• 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:

• Captured using N.I.N.A. and PHD2 for guiding and dithering.

PixInsight Processing:

• BatchPreProcessing

• SubframeSelector

• StarAlignment

• Blink

• 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:

• PixelMath to combine Ha and luminance stacks to make super-luminance image (to be used as the luminance layer going forward)

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