• 105 Posts
  • 194 Comments
Joined 1 year ago
cake
Cake day: July 13th, 2023

help-circle



  • 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





  • 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 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



  • If you’re going into deep sky imaging, getting a solid tracking mount will be more important than a specific camera/lens. I’ll be honest I haven’t really bought new gear or looked at new equipment in the last few years, but this vid from Alaskan Astro is a great overview and recommendations for beginner setup (I see the 135mm f/2 has already been recommended in here lol). It’s also worth checking out used equipment if you’re on a budget. I’ve found some great deals on the cloudynights classifieds, craigslist, and FB marketplace when I was assembling my rig.

    Also since you want to use your camera for astro and normal photography, you can still use a H-alpha modded camera, but just use a custom white balance for non-astro shots. Personally I wouldn’t worry too much about getting a modded cam if you’re just starting out in the hobby, but it’s something you may want to consider if you want to shoot a lot of emission nebulae