any recommended apps for astrophotography?

categories: desktop, phone, dedicated camera postprocessing

in the spirit of Lemmy, let's try for FOSS only this thread.

I'll start: GIMP is great for doing stacking and color correction.

Decided to go with a blend of OSH + Jimmy's Royal Palette (math below) instead of a typical Hubble palette that I use for most of my SHO images. This photo is a 2 panel mosaic. Because M8 is fairly low declination, I had to use a laser to turn off the streetlamp at the end of my driveway while shooting it (more for the guidecam than for the main narrowband pics). Overall I'd consider this an improvement over my previous bicolor pic of the nebula from 2019.

Captured on April 24th and 25th, 2022, from a Bortle 6 zone.

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-290mc for guiding

• Moonlite Autofocuser

Acquisition: 4 hours 55 minutes (Camera at unity gain, -15°C)

Left Panel:

• Ha - 10x300"

• Oiii - 10x300"

• Sii - 8x300"

RightPanel:

• Ha - 12x300"

• Oiii - 10x300"

• Sii - 9x300"

• 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)

Making the mosaic:

• StarAlign left Ha panel to right (Register/union mosaic mode) to make master mosaic

• StarAlign all panels from all filters to master mosaic (register/match mode)

• GradientMergeMosaic to combine aligned panels into single mosaic image per filter

Linear:

• DynamicCrop

• AutomaticBackgroundExtraction

• EZ Decon

• NoiseXTerminator

• STF applied via HistogramTransformation to bring each channel nonlinear

Combining channels into color photo:

• ChannelCombination combine monochrome Ha Oiii and Sii images into a color image with OSH palette

• PixelMath to make a second image using /u/JimmyTheChicken1's Royal 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-Oiii

• PixelMath to blend OSH and Jimmy pics together 60:40

Nonlinear:

• LRGBCombination with stretched Ha as luminance

• Stars extracted and saved separately using StarXTerminator

From here I duplicated the pic and exported one as a 32-bit tiff. From here I brought it into Photoshop and converted it to a 16-bit tiff using the 'local adaptation' mode. For some reason I kinda like the softer 'dreamy' look this gave it. Then I brought the photo back into PixInsight

• Both images had some curve and SCNR green adjustments done to them

• Separate stars image was also SCNR'd green, and added back to the images via PixelMath

• PixelMath to combine the two separate nonlinear pics into a single pic 50:50 (will be the only one used going forward)

• Extract L --> LRGBCombination for chrominance noise reduction

• NoiseXTerminator

• LocalHistogramEqualization

Two rounds of this. one at size 16 for the finer 'feathery' details and one at size 500 for large scale structures

• Shitloads of CurveTransformations to adjust lightness, saturation, contrast, hues, etc.

• EZ HDR at like 5% blend or something

• DarkStructureEnhance

• Resample to 75%

• Annotation

Apparently it's called the crescent nebula because that's what it looks like through a visual telescope. I think it looks more like a scrotum ¯\_(ツ)_/¯

This is my third time shooting the Crescent Nebula! I had first shot it back in 2017 when I still used a DSLR for astrophotography. I still use the same scope, but eventually upgraded to a monochrome astro cam, and this was my first target using Hydrogen alpha + Oxygen-iii narrowband filters in 2019. Last year I decided to shoot it again, although I combined this data with the data from 2019 since my setup then was identical to how it is now. I did have to heavily crop in on this image due to differing camera rotations, but I ended up with a higher signal to noise ratio overall by combining the data. I also made a starless version of this pic which better shows off the faint nebulosity, including the Soap Bubble Nebula in the bottom left.

Captured over 5 nights in May 2019 (Bortle 7) and 4 nights in May 2022 (Bortle 6)

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: 26 hours 5 minutes (Camera at Unity Gain, -15°C)

• Ha - 61x360" + 88x300"

• Oiii - 54x360" + 87x300"

• 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)

• DynamicCrop

• DynamicBackgroundExtraction

• EZ Decon

• NoiseXTerminator

• STF applied via HT to bring each image nonlinear

Combining Channels:

really like how the colors turned out on this, especially the slight gold/yellow in the nebula compared to the red in the background

• Pixelmath to make RGB image using ForaxX's HOO palette:

R= Ha

G= ((Oiii*Ha)^~(Oiii*Ha))*Ha + ~((Oiii*Ha)^~(Oiii*Ha))*Oiii

B= Oiii

Nonlinear:

• LRGBCombination with extracted L as luminance, used for chrominance noise reduction

• Shitloads of CurveTransformations to adjust lightness, saturation, contrast, hues, etc. with various masks

• NoiseXTerminator

• More Curves

• EZ star reduction

• NoiseGenerator to add noise into reduced star areas

• Even more curves

• ColorSaturation to better bring out the Oiii regions

• More NoiseX

• Resample to 80%

• Annotation

Also pictured is M21! (the star cluster to the top left of the nebula)

Very pleased with how this one turned out! Despite guide camera issues for the first hour of the night, and horrific seeing/guiding error/HFR values, this somehow turned out decent. I also made a starless version which better shows the fainter/diffuse nebulosity.

Captured on April 20th, 2023 from the Deerlick Astronomy Village (Bortle 3)

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~~ 290mc for guiding

• Moonlite Autofocuser

Acquisition: 2 hours 36 minutes (Camera at half Unity Gain, -15°C)

• L- 37x120"

• R - 14x120"

• G - 13x120"

• B - 14x120"

• 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)

Luminance Linear:

• DynamicCrop

• DynamicBackgroundExtraction

copied the image and ran starx on it. then ran DBE and output the background model as 'model'. subtracted this from the original using PixelMath:

$T * med(model) / model

• BlurXTerminator (i caved)

• NoiseXterminator

• ArcsinhStretch+HistogramTransformation to bring nonlinear

RGB Linear:

• DynamicCrop

• DynamicBackgroundExtraction

same DBE process as above

• Blur+NoiseX

• ChannelCombination

• SpectrophotometricColorCalibration

• HSV Repair

• AcrsinhStretch + HistogramTransformation to stretch nonlinear

Nonlinear:

• added stretch luminance to stretched RGB via LRGBCombination

• DeepSNR

• SCNR green

• shitloads of CurveTransformations to adjust hue, lightness, saturation, etc. (some with star masks)

• Extract L --> LRGBCombination again for chrominance noise reduction (inverted L image used as mask)

• more curves

• LocalHistogramTransformation

Two round of this: one at kernel radius 16 for the finer 'feathery' details and one at 254 for larger structures

• even more curves

• BlurXTerminator (star reduction only)

• DarkStructureEnhance

• guess what more curves

• ColorSaturation

• final curves

• Resample to 70%

• DynamicCrop again

• annotation

copy/paste of the deets from when I originally posted it on the reddit last november:

So despite doing astrophotography for over 5 years I've never gotten an image of M31 that I've completely liked until now. My last real attempt at it was in 2019, and looking back has some obvious noise reduction and color gradient issues (tbf I shot it from downtown Athens, GA). I recently visited my future in laws, who happen to live in the middle of nowhere, so I brought along my telescope to take some deep space pics. I also incorporated some hydrogen-alpha data from a while ago to help boost the Hii regions (the red splotches) in the galaxies a bit. At first I wasn't sure about the addition of the Ha data, so I ended up processing this image twice from scratch, one with Ha and one without. There were parts of each that I liked and disliked, so I blended the two finished pics together, and was very pleased with the results, which is the final image you see above. also here's a starless version for the hell of it. Captured on November 17th, 2022, from a Bortle 4 zone (Ha data was captured in October 2020 from a Bortle 6 zone)

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-290mc for guiding

• Moonlite Autofocuser

Acquisition: 11 hours 14 minutes (Camera at Unity Gain(Ha) and half unity (LRGB), -15°C)

• L- 46x120"

• R- 20x120"

• G- 18x120"

• B- 18x120"

• Ha -47x300" x 2 panels

• 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

• automaticBackgroundExtraction

• EZ Decon

• NoiseXTerminator

• ArcsinhStrecth + HistogramTransformation to bring nonlinear

RGB Linear:

• Channelcombination to combine monochrome images into RGB image

• PhotometricColorCalibration

• SCNR green

• HSV Repair

Adding Ha:

I followed this tutorial which had great results on some prior HaLRGB galaxy pics:

http://www.arciereceleste.it/tutorial-pixinsight/cat-tutorial-eng/85-enhance-galaxy-ha-eng

• PixelMath to make Clean Ha. This effectively isolates just the Ha regions from the red continuum spectrum

Ha-Q * (Red-med (Red))

Q=0.15

• 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=1

Nonlinear Processing:

• PixelMath to add original RGB image into the gaps from the old Ha data

• Slight SCNR

• ArcsinhStretch + HistogramTransformations to stretch nonlinear

The RGB image without Ha was processed almost identically as above, minus the Ha addition steps. while nonlinear they were processed pretty similarly, so I'm just going to list out the general steps as they broadly apply to both images:

Nonlinear:

• LRGBCombination with stretched luminance

• Shitloads of CurveTransformations to adjust lightness, saturation, contrast, hues, etc.

• Extract L --> LRGBCombination for chrominance noise reduction

• color saturation to slightly desaturate the Ha regions

• More curves

• SCNR > Invert > SCNR > invert to remove some greens and magentas

• LocalHistogramEqualization

Two rounds of this. one at size 16 for the finer 'feathery' details and one at size 500 for large scale structures

• even more curves

• NoiseXTerminator

• EZ Star Reduction

• noise generator to add noise back into star reduced areas

• guess what baby more curves

PixelMath to combine the two fully processed images 50:50

• Another round of EZ star reduction, NoiseXTerminator, and LRGBCombination chrominance noise reduction

• HEY DID YOU KNOW I LIKE USING THE CURVESTRANSFORMATION PROCESS?

• Resample to 60%

• Annotation

Sh2-114 (the Flying Dragon Nebula) is a very faint and rarely imaged nebula located in the constellation of Cygnus. The nebula has not been studied much and still doesn't seem to be a common target for astrophotography. This large curving filamentary structure appears part of a supernova, but no supernova remnant has yet been identified as the source.

After about 13.5hs and four sessions, the weather turned, so I have to be content with the data for now. Processing was challenging and I believe another 10hs or so would be beneficial. It was fun making the dragon appear.

The place where I host my other images: AstroBin

Equipment:

• Telescope: Esprit 120ED
• Riccardi Reducer M82
• Mount: iOptron GEM45
• Camera: QHY268c
• Guide Camera: QHY5III462c
• Off Axis Guider: OAG-M
• Filter: IDAS NBZ
• Switch: PegasusAstro Ultimate Powerbox v2
• Focuser: PegasusAstro Focus Cube

Acquisition: 13h 30′

• Darks: 25
• Flats: 30
• DarkFlats: 30

Software:

• NINA
• PHD2

Processing:

PixInsight Ripley

• Blink
• Subframe Selector
• Stacking - WeightedBatchPreProcessing
• Remove Remove Vignetting - DynamicBackgroundExtraction
• Remove Remove Gradience - DynamicBackgroundExtraction
• Deconvolution using BlurXTerminator
• Denoise using NoiseXTerminator
• Stretch using GeneralizedHyperbolicStretch
• Curves
• Shrink Stars (Blanshan’s PixelMath Star Reduction)
• Final Stretch
• Final Curves

IMO the 'heart' looks more like a chode with huge balls

This is my most ambitious astrophotography project yet, coming in at over 110 hours 18 minutes of total exposure time (albeit across 12 panels), beating out my previous record of 101 hours on the Elephant Trunk Nebula

The 12 panel mosaic ended up being 518 megapixels in size after cropping, and was an absolute bitch to process. probably never gonna do a mosaic this big again unless I have some quantum supercomputer. I don't have any way to reliably host this on my flickr page, so the image you're seeing is a 2X downsample.

Captured over 35 nights from October 2022 through March 2023, from my Bortle 8 apartment balcony

could only do 4 hours max per night thanks to my wonderful horizons from the balcony overhang

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: 110 hours 18 minutes (Camera at -15°C)

all narrowband exposures were 360" and unity gain

all broadband exposures were 30" and at half unity gain

• Darks- 30

• Flats- 30 per filter

Capture Software:

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

PixInsight processing:

/u/Aerions_'s Heart and Fishhead pic was a bit of an inspiration for me when processing this (and imo their colors are better)

Preprocessing

• BatchPreProcessing

• StarAlignment

• Blink

• ImageIntegration per channel per panel

• DrizzleIntegration (2x, Var β=1.5) per panel per channel

Creating the mosaic:

I had numerous other attempts to make this using microsoft ICE and mosaicbycoordinates/photometricmosaic, but they all refused to work that well. During this process I found out that the .tiff file format has a max size of around 530 megapixels

• StarGenerator to generate a starfield of the region at the same image scale as my drizzled images

• StarAlignment to align each drizzled stack to the synthetic starfield

despite reading all the documentation and tinkering with every setting, my blue stars channel for panel 11 refused to align properly with any of the other channels, so the stars here are a bit mismatched

• GradientMergeMosaic to combine these aligned panels into the master stacks

• DynamicCrop away the edges of each master

Narrowband Linear:

• DynamicBackground Extraction

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 (thanks, /u/jimmythechicken1!)

$T * med(model) / model

• BlurXTerminator

• StarXterminator to completely remove stars (narrowband images will be starless processed for almost the rest of the workflow)

• NoiseXterminator

• HistogramTransformations to bring nonlinear

More agressive stretch for Oiii and Sii

RGB Linear:

• ChannelCombination to combine R G and B masters into a color image

• SpectrophotometricColorCalibration

• HSV Repair

• StarXterminator to make a stars only image (this stars only image to be used going forward)

• AcrsinhStretch + HistogramTransformation to stretch nonlinear

Nonlinear:

did this over the course of a couple weeks/processing breaks so the details aren't exact

• PixelMath to combine stretched narrowband masters into color image

SHO --> RGB (classic Hubble Palette)

• HistogramTransformations to adjust channel intensities

• CurveTransformations for slight hue adjustments

• LRGBCombination using stretched Ha as luminance

• shitloads of CurveTransformations to adjust hue, lightness, saturation, etc. (some with lum masks)

• invert > SCNR > invert to remove background magentas

• probably used BackgroundNeutralization at some point around here too

• LocalHistogramEqualization

Two round of this: one at kernel radius 16 for the finer 'feathery' details and one at 200+ for larger structures

• more curves!

• NoiseXterminator

• more histogramtransformation tweaks

• DarkStructureEnhance

• Relinearized narrowband and stars images to add in the RGB stars

"unstretched" both images with histogramtransformation midtones set to 0.9999

pixelmath to just add those two images together

histogramtransformation to un-relinearize them by setting midtones to 0.0001

• ColorSaturation

• MLT for chrominance noise reduction

• final round of noiseX

• guess what baby more curves

• one final round of DBE to remove a small red gradient in the bottom corner that made it through to the end somehow

just to please Jimmy

• IntegerResample to 50%

• annotation

This is the great globular in Hercules. One of the first awe inspiring celestial objects I ever looked at through a visual telescope. This is my third time imaging this target and my goal was to go deep and to bring out as many stars as possible without blowing out the core. Captured over 30 hours of integration time from my ROR observatory in my backyard. Also available on Astrobin here.

Main Camera: Canon 6D

Main Lens: Tamron 150-600 @ 600mm

Guide camera: ASI 120m

Guide scope: Orion mini 50mm

Mount/tracking: Tripod + Star Adventurer

Light frames: 36 @ 100s each

No dark or bias frames

Taken on 2020-02-24 from my back yard (roughly bortle 6)

Processing, I don't remember exact details but roughly:

• stacked in deep sky stacker
• adjusted levels in Photoshop
• removed some light pollution in Photoshop

Since there is a single post, i think it would be better to populate by starting with sub-optimal pics

This was my first real crack at astrophotography (captured last August). Taken with my Nikon D7100, 50mm f/1.8 reduced to f/2.8, untracked on an Amazon basics tripod (I've gotten a nicer tripod since then and am in the process of making a barn door tracker).

339 lights at 5" (28' total exposure) @ ISO 2500, 50 darks, 50 bias, 50 flats.

Stacked in DSS, Post-Processed in GIMP (I'm still trying to figure this out). I've started using Siril primarily since taking this.

I've learned much more about post-processing since I took this last year and should probably reprocess this. I found out after taking this that I have a little mold in this lens ( hence the smudged corner) and have gotten a few new ones since, but all in I'm pretty happy with this for my first time.

Interested in getting started with astrophotography or have a question about the community? Most information can be found on our wiki. If you have any suggestions/feedback please let us know and we'll do our best to add it.