He’s just a skeegy little guy
He’s just a skeegy little guy
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
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
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
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
Iirc the original goal was ‘at least 10’ but maybe up to 100 flights for a booster. No way to really know without flying them a lot
It’s definitely real, at least for the amateur astronomy subs I (used to) mod. I suspect a lot of the traffic to askastrophotography or telescopes is from people googling stuff and browsing though mobile web, but since /r/astrophotography is just photos, most are just on the app
Probably varies a bit from sub to sub, but old reddit users are a clear minority. The vast majority use the app
NASA is still doing a seat exchange and launching Johnny Kim on the next Soyuz in March, but it looks like it’ll be just Russians on at least the next 2 Soyuz’s after that
with my luck it’s gonna pop in november just after it sinks behind some trees for the season
I made this comparison a while ago, and figured I’d share it since I’ve seen some headlines going around the last couple days…
The Moon’s orbit isn’t a perfect circle, and at times is a little closer and a little farther away from Earth. It’s called a supermoon when the moon is full and at its closest point, and a micromoon when its full and at its furthest point
I wanted to make this comparison to highlight that the supermoon isn’t really that much larger than normal. Personally I think the supermoon is overhyped for what it is, and that it’s hard to tell visually that the moon is larger or smaller, unless you do a direct comparison like this. The moon can appear larger than normal when its close to the horizon, but the actual size of it is no different than if it was straight overhead: https://en.wikipedia.org/wiki/Moon_illusion
The angular diameters and distances were taken from a planetarium program called Stellarium. I compared the pixel measurements of my photos to the values calculated by Stellarium, and the discrepancy was only 0.22%.
TPO 6" F/4 Imaging Newtonian
ZWO ASI1600MM-Pro
Skywatcher Quattro Coma Corrector
ZWO EFW 8x1.25"/31mm
Astronomik LRGB+CLS Filters- 31mm
Moonlite Autofocuser
Acquisition: (Camera at Unity Gain, -20°C for supermoon, -10°C for micromoon)
Astronomik Red filter used to combat atmospheric seeing
Exposure- 0.213ms for supermoon, 1.115ms for micromoon
1000 frame capture for supermoon
2000 frame capture for micromoon
Capture Software:
Processing:
Supermoon: Best 10% of frames stacked in Autostakkert!3
Micromoon: Best 25% of frames stacked
Registax Wavelets for sharpening on both images
Level and curve adjustments in Photoshop
Images combined and annotated in Photoshop
It may not be as big or well known as the other well known cluster in Hercules (M13), but it sure looks nice. Captured over 4 nights in July/August 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-120MC for guiding
Moonlite Autofocuser
Acquisition: 6 hours 55 minutes (Camera at half Unity Gain, -15°C)
Lum - 209x60"
Red - 78x60"
Green - 62x60"
Blue - 66x60"
Flats- 30 per filter
24 JimmyFlats per 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 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
Luminance:
BlurXTerminator (correct only mode)
ArcsinhStretch + histogramtransformation to bring nonlinear
RGB:
ChannelCombinaiton to combine monochrome R, G, B stacks into color image
BlurXTerminator (correct only mode)
SpectroPhotometricColorCalibration
HSV Repair
ArcsinhStretch + histogramtransformation to bring nonlinear
Curves to saturate it a little
MLT for large scale chrominance noise reduction
Nonlinear:
LRGBCombination with stretched L as luminance
DeepSNR Noise reduction
Several CurveTransformations to adjust lightness, contrast, colors, saturation, etc.
Invert > SCNR > invert > SCNR to remove some greens and magentas
More curves
A little bit of noiseXterminator
DynamicCrop in on the clustert
Resample to 75%
Annotation
It may not be as big or well known as the other well known cluster in Hercules (M13), but it sure looks nice. Captured over 4 nights in July/August 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-120MC for guiding
Moonlite Autofocuser
Acquisition: 6 hours 55 minutes (Camera at half Unity Gain, -15°C)
Lum - 209x60"
Red - 78x60"
Green - 62x60"
Blue - 66x60"
Flats- 30 per filter
24 JimmyFlats per 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 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
Luminance:
BlurXTerminator (correct only mode)
ArcsinhStretch + histogramtransformation to bring nonlinear
RGB:
ChannelCombinaiton to combine monochrome R, G, B stacks into color image
BlurXTerminator (correct only mode)
SpectroPhotometricColorCalibration
HSV Repair
ArcsinhStretch + histogramtransformation to bring nonlinear
Curves to saturate it a little
MLT for large scale chrominance noise reduction
Nonlinear:
LRGBCombination with stretched L as luminance
DeepSNR Noise reduction
Several CurveTransformations to adjust lightness, contrast, colors, saturation, etc.
Invert > SCNR > invert > SCNR to remove some greens and magentas
More curves
A little bit of noiseXterminator
DynamicCrop in on the clustert
Resample to 75%
Annotation
I originally planned on shooting this from a dark site on top of a mountain but my laptop had other plans. Ended up taking this from my driveway instead (at least when I still had a driveway), but I’m very pleased with the detail I got at just 610mm focal length. There are also a number of other galaxies in the uncropped pic including one over a billion light years away from us (calculated from redshift). 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 enhance the hydrogen nebulae in the galaxy (red splotches in the spiral arms). Captured on March 21, 22, 24, and 29th, 2021 from a Bortle 6 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-120MC for guiding
Moonlite Autofocuser
Acquisition: 10 hours 2 minutes (Camera at Unity Gain, -15°C)
Lum - 106x120"
Ha - 30x300"
Red - 40x120"
Green - 40x120"
Blue - 50x120"
Darks- 30
Flats- 30 per filter
Capture Software:
PixInsight Processing:
BatchPreProcessing
StarAlignment
ImageIntegration
DrizzleIntegration (2x, Var β=1.5) (Lum only)
StarAlign Ha, R, G, B stacks to drizzled L
DynamicCrop
DynamicBackgroundExtraction
Luminance:
EZ Decon + Denoise
ArcsinhStretch + histogramtransformation to bring nonlinear
RGB:
ChannelCombinaiton to combine monochrome R, G, B stacks into color image
PhotometricColorCalibration
SCNR green
Adding Ha:
I followed this tutorial which I find produces much better results than my previous NBRGBCombination script technique:
http://www.arciereceleste.it/tutorial-pixinsight/cat-tutorial-eng/85-enhance-galaxy-ha-eng
Ha-Q * (Red-med (Red))
Q=1.0416
PixelMath to combine Clean Ha
PixelMath to add Ha to RGB image ($T)
R= $T+B*(Ha_Clean - med(Ha_Clean))
G= $T
B= $T+B*0.2*(Ha_Clean - med(Ha_Clean))
B=3
HaRGB:
Slight SCNR
HSV Repair
ArcsinhStretch + histogramtransformation to bring nonlinear
ColorSaturation to slightly desaturate Ha regions
HistogramTransformation to further stretch to match lum brightness
Nonlinear:
LRGBCombination with stretched L as luminance
Several CurveTransformations to adjust lightness, contrast, colors, saturation, etc.
MoreSCNR
ACDNR
LocalHistogramEqualization
More Curves
ColorSaturation to slightly desaturate Ha regions
MMT noise reduction
EZ StarReduction
Final Curves
Resample to 60%
DynamicCrop to 3555x2000
Annotation
Oh no! Where will I go to see OF spam bots now???
It looks like walking/raining noise, and it’s usually caused by not dithering. On a lot of setups you dither every few exposures by moving the scope a few pixels in a random direction, and when everything is realigned and stacked, it should remove the noise.
I’m not that familiar with smart telescopes, but see if it has a dither function built in. On more typical rigs you’d dither by moving a guide star over, and I think NINA can just blindly slew a mount a few arcseconds if there’s no guider attached.
Love the colors!