• 105 Posts
  • 187 Comments
Joined 1 year ago
Cake day: July 13th, 2023
  • lefty7283@lemmy.worldtoAsklemmy@lemmy.ml•Do you consistently use Anki? Why?English
    9·
    8 days ago

    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.

  • lefty7283@lemmy.worldOPtopics@lemmy.world•NGC 4490 - The Cocoon Galaxy [OC]English
    4·
    2 months ago

    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:

    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

  • lefty7283@lemmy.worldOPMtoAstrophotography@lemmy.world•NGC 4490 - The Cocoon GalaxyEnglish
    4·
    2 months ago

    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:

    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

  • lefty7283@lemmy.worldOPMtoAstrophotography@lemmy.world•The Horsehead NebulaEnglish
    2·
    2 months ago

    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

  • lefty7283@lemmy.worldMtoAstrophotography@lemmy.world•Budget setupEnglish
    1·
    2 months ago

    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

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