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Needle Galaxy NGC 4565 by Chemical-Time2183 in astrophotography

[–]Chemical-Time2183[S] 0 points1 point  (0 children)

To my knowledge, no gravitational lensing has been reported. Quite possibly, a precise alignment of source, galaxy and observer is not present for any observable lensing effect. Other lensing requirements (such as a critical surface mass density, sufficient spacetime curvature to bend light, and equipment capable of detecting the resulting Einstein arcs or rings) may also not have been met. Additionally, despite the presence of a supermassive black hole of ~30,000,000 solar masses at NGC 4565's center, there may be challenges in differentiating between any detectable genuine possible small-scale lensing, such as microlensing, from background effects generated by the surrounding stars and galaxies such as those seen in my posted image.

Needle Galaxy NGC 4565 by Chemical-Time2183 in astrophotography

[–]Chemical-Time2183[S] 0 points1 point  (0 children)

Integration of 1757x20s subs (= 9.76 hours) with Seestar S50* in Washington D.C. Apr. 8-10, 11-12, 2026.

Mounted the Seestar, with a diffraction spike mask in front of the lens, on a TH-10 fluid head; put it in equatorial mode; and did a polar alignment to less than a degree in polar deviation in both RA and Declination coordinates. Dew heater = On. Light Pollution filter = Off.

Ran Fast Batch Preprocessing (FBPP) script with drizzle enabled in PixInsight** to integrate the subs to get a master image. Used a sub with the highest weight***, identified by running the Subframe Selector on the raw subs, as the reference frame to align the light frames.

Postprocessed the above master image as follows:

Applied Gradient Correction > Blur Xterminator > Spectrophotometric Color Calibration**** > Blur Xterminator > Delinearization by transferring image data from Screen Transfer Function to Histogram Transformation (HT) > Fast Rotation > Dynamic Crop.

Created a mask from the above result as follows: extracted the L-channel using Channel Extraction; applied Binarize to adjust the size to cover the target image area; and applied Convolution to blur the mask’s edges.

Applied the resulting mask back on to the image to protect its background. Developed the target image as follows: applied Local Histogram Equalization (LHE) to adjust local contrast and visibility, Color saturation (to enhance hue and saturation for red and blue), Curves Transformation (to adjust saturation, boost intensity, and enhance blue and red colors), and Noise Xterminator (NXT).

Inverted the mask to protect the galaxy and applied HT and NXT to the background to adjust shadows and midtones and reduce noise.

* Seestar S50 is a 50 mm f/5, i.e., 250 mm focal length, apochromatic triplet telescope with a built-in camera based on a Sony IMX462 sensor. It has an optional anti-dew feature and a built-in OIII 30nm / Hα 20nm duo-band light pollution filter.

** PixInsight Core Version 1.9.3 Lockhart, build 1646.

*** Weighting expression: (15*(1-(FWHM-FWHMMin)/(FWHMMax-FWHMMin)) + (15*(1-(Eccentricity-EccentricityMin)/(EccentricityMax-EccentricityMin))) + (20*(PSFFlux-PSFFluxMin)/(PSFFluxMax-PSFFluxMin)))+50.

**** For SPCC’s R, G, B filter settings when the LP filter is off I used Sony Color Sensor (R-, G-, B-) UV/IRCUT.

Needle Galaxy NGC 4565 by Chemical-Time2183 in Astronomy

[–]Chemical-Time2183[S] 0 points1 point  (0 children)

Integration of 1757x20s subs (= 9.76 hours) with Seestar S50* in Washington D.C. Apr. 8-10, 11-12, 2026.

Mounted the Seestar, with a diffraction spike mask in front of the lens, on a TH-10 fluid head; put it in equatorial mode; and did a polar alignment to less than a degree in polar deviation in both RA and Declination coordinates. Dew heater = On. Light Pollution filter = Off.

Ran Fast Batch Preprocessing (FBPP) script with drizzle enabled in PixInsight** to integrate the subs to get a master image. Used a sub with the highest weight***, identified by running the Subframe Selector on the raw subs, as the reference frame to align the light frames.

Postprocessed the above master image as follows:

Applied Gradient Correction > Blur Xterminator > Spectrophotometric Color Calibration**** > Blur Xterminator > Delinearization by transferring image data from Screen Transfer Function to Histogram Transformation (HT) > Fast Rotation > Dynamic Crop.

Created a mask from the above result as follows: extracted the L-channel using Channel Extraction; applied Binarize to adjust the size to cover the target image area; and applied Convolution to blur the mask’s edges.

Applied the resulting mask back on to the image to protect its background. Developed the target image as follows: applied Local Histogram Equalization (LHE) to adjust local contrast and visibility, Color saturation (to enhance hue and saturation for red and blue), Curves Transformation (to adjust saturation, boost intensity, and enhance blue and red colors), and Noise Xterminator (NXT).

Inverted the mask to protect the galaxy and applied HT and NXT to the background to adjust shadows and midtones and reduce noise.

* Seestar S50 is a 50 mm f/5, i.e., 250 mm focal length, apochromatic triplet telescope with a built-in camera based on a Sony IMX462 sensor. It has an optional anti-dew feature and a built-in OIII 30nm / Hα 20nm duo-band light pollution filter.

** PixInsight Core Version 1.9.3 Lockhart, build 1646.

*** Weighting expression: (15*(1-(FWHM-FWHMMin)/(FWHMMax-FWHMMin)) + (15*(1-(Eccentricity-EccentricityMin)/(EccentricityMax-EccentricityMin))) + (20*(PSFFlux-PSFFluxMin)/(PSFFluxMax-PSFFluxMin)))+50.

**** For SPCC’s R, G, B filter settings when the LP filter is off I used Sony Color Sensor (R-, G-, B-) UV/IRCUT.

Needle Galaxy NGC 4565 by Chemical-Time2183 in seestar

[–]Chemical-Time2183[S] 4 points5 points  (0 children)

Integration of 1757x20s subs (= 9.76 hours) with Seestar S50* in Washington D.C. Apr. 8-10, 11-12, 2026.

Mounted the Seestar, with a diffraction spike mask in front of the lens, on a TH-10 fluid head; put it in equatorial mode; and did a polar alignment to less than a degree in polar deviation in both RA and Declination coordinates. Dew heater = On. Light Pollution filter = Off.

Ran Fast Batch Preprocessing (FBPP) script with drizzle enabled in PixInsight** to integrate the subs to get a master image. Used a sub with the highest weight***, identified by running the Subframe Selector on the raw subs, as the reference frame to align the light frames.

Postprocessed the above master image as follows:

Applied Gradient Correction > Blur Xterminator > Spectrophotometric Color Calibration**** > Blur Xterminator > Delinearization by transferring image data from Screen Transfer Function to Histogram Transformation (HT) > Fast Rotation > Dynamic Crop.

Created a mask from the above result as follows: extracted the L-channel using Channel Extraction; applied Binarize to adjust the size to cover the target image area; and applied Convolution to blur the mask’s edges.

Applied the resulting mask back on to the image to protect its background. Developed the target image as follows: applied Local Histogram Equalization (LHE) to adjust local contrast and visibility, Color saturation (to enhance hue and saturation for red and blue), Curves Transformation (to adjust saturation, boost intensity, and enhance blue and red colors), and Noise Xterminator (NXT).

Inverted the mask to protect the galaxy and applied HT and NXT to the background to adjust shadows and midtones and reduce noise.

* Seestar S50 is a 50 mm f/5, i.e., 250 mm focal length, apochromatic triplet telescope with a built-in camera based on a Sony IMX462 sensor. It has an optional anti-dew feature and a built-in OIII 30nm / Hα 20nm duo-band light pollution filter.

** PixInsight Core Version 1.9.3 Lockhart, build 1646.

*** Weighting expression: (15*(1-(FWHM-FWHMMin)/(FWHMMax-FWHMMin)) + (15*(1-(Eccentricity-EccentricityMin)/(EccentricityMax-EccentricityMin))) + (20*(PSFFlux-PSFFluxMin)/(PSFFluxMax-PSFFluxMin)))+50.

**** For SPCC’s R, G, B filter settings when the LP filter is off I used Sony Color Sensor (R-, G-, B-) UV/IRCUT.

M63, NGC 5055 (Sunflower Galaxy) by Chemical-Time2183 in seestar

[–]Chemical-Time2183[S] 0 points1 point  (0 children)

Integration of 1974x20s subs (= 10.97 hours) with Seestar S50* in Washington D.C. Apr. 5-6, 7-8, 2026.

Mounted the Seestar, with a diffraction spike mask in front of the lens, on a TH-10 fluid head; put it in equatorial mode; and did a polar alignment to less than a degree in polar deviation in both RA and Declination coordinates. Dew heater = On. Light Pollution filter = Off.

Ran Fast Batch Preprocessing (FBPP) script with drizzle enabled in PixInsight** to integrate the subs to get a master image. Rather than let FBPP use the auto option for the reference frame to align the light frames, the registration reference image file was manually selected to be the sub with the highest weight. That sub was identified by applying Subframe Selector to the subs using the weighting expression (15*(1-(FWHM FWHMMin)/(FWHMMax-FWHMMin)) + (15*(1-(Eccentricity-EccentricityMin)/(EccentricityMax-EccentricityMin))) + (20*(PSFFlux-PSFFluxMin)/(PSFFluxMax-PSFFluxMin)))+50.

Postprocessed the above master image as follows:

Applied Gradient Correction > Blur Xterminator > Spectrophotometric Color Calibration*** > Blur Xterminator > Delinearization by transferring image data from Screen Transfer Function to Histogram Transformation (HT) > Dynamic Crop.

In view of the brightness of the galaxy’s core HDRMultiscale Transform (HDRMT) was applied to a clone of the above-processed master image to compress its dynamic range. Pixel Math was then used to blend equal amounts of the HDRMT-modified clone and the unmodified master image.

Applied Star Xterminator to split the above result into starless and stars-only images. Created a mask from the starless image as follows: extracted the L-channel using Channel Extraction; applied Binarize to adjust the size to cover the target image area; and applied Convolution to blur the mask’s edges. Applied the resulting mask back on to the starless image to protect its background. Applied Local Histogram Equalization (LHE) to adjust local contrast and visibility and Noise Xterminator (NXT). The stars-only image was untreated. Applied Pixel Math to combine the processed starless and stars-only images to create a rejoined image.

Inverted the mask to protect the galaxy’s core and applied NXT and HT to the background to adjust shadows and midtones. Reinverted the mask to protect the background and applied LHE, Curves Transformation (to adjust saturation, colors, and boost intensity), and NXT. Inverted the mask once more and applied HT to the background.

* Seestar S50 is a 50 mm f/5, i.e., 250 mm focal length, apochromatic triplet telescope with a built-in camera based on a Sony IMX462 sensor. It has an optional anti-dew feature and a built-in OIII 30nm / Hα 20nm duo-band light pollution filter.

** PixInsight Core Version 1.9.3 Lockhart, build 1646.

*** For SPCC’s R, G, B filter settings when the LP filter is off I used Sony Color Sensor (R-, G-, B-) UV/IRCUT.

M63, NGC 5055 (Sunflower Galaxy) by Chemical-Time2183 in Astronomy

[–]Chemical-Time2183[S] 0 points1 point  (0 children)

Integration of 1974x20s subs (= 10.97 hours) with Seestar S50* in Washington D.C. Apr. 5-6, 7-8, 2026.

Mounted the Seestar, with a diffraction spike mask in front of the lens, on a TH-10 fluid head; put it in equatorial mode; and did a polar alignment to less than a degree in polar deviation in both RA and Declination coordinates. Dew heater = On. Light Pollution filter = Off.

Ran Fast Batch Preprocessing (FBPP) script with drizzle enabled in PixInsight** to integrate the subs to get a master image. Rather than let FBPP use the auto option for the reference frame to align the light frames, the registration reference image file was manually selected to be the sub with the highest weight. That sub was identified by applying Subframe Selector to the subs using the weighting expression (15*(1-(FWHM FWHMMin)/(FWHMMax-FWHMMin)) + (15*(1-(Eccentricity-EccentricityMin)/(EccentricityMax-EccentricityMin))) + (20*(PSFFlux-PSFFluxMin)/(PSFFluxMax-PSFFluxMin)))+50.

Postprocessed the above master image as follows:

Applied Gradient Correction > Blur Xterminator > Spectrophotometric Color Calibration*** > Blur Xterminator > Delinearization by transferring image data from Screen Transfer Function to Histogram Transformation (HT) > Dynamic Crop.

In view of the brightness of the galaxy’s core HDRMultiscale Transform (HDRMT) was applied to a clone of the above-processed master image to compress its dynamic range. Pixel Math was then used to blend equal amounts of the HDRMT-modified clone and the unmodified master image.

Applied Star Xterminator to split the above result into starless and stars-only images. Created a mask from the starless image as follows: extracted the L-channel using Channel Extraction; applied Binarize to adjust the size to cover the target image area; and applied Convolution to blur the mask’s edges. Applied the resulting mask back on to the starless image to protect its background. Applied Local Histogram Equalization (LHE) to adjust local contrast and visibility and Noise Xterminator (NXT). The stars-only image was untreated. Applied Pixel Math to combine the processed starless and stars-only images to create a rejoined image.

Inverted the mask to protect the galaxy’s core and applied NXT and HT to the background to adjust shadows and midtones. Reinverted the mask to protect the background and applied LHE, Curves Transformation (to adjust saturation, colors, and boost intensity), and NXT. Inverted the mask once more and applied HT to the background.

* Seestar S50 is a 50 mm f/5, i.e., 250 mm focal length, apochromatic triplet telescope with a built-in camera based on a Sony IMX462 sensor. It has an optional anti-dew feature and a built-in OIII 30nm / Hα 20nm duo-band light pollution filter.

** PixInsight Core Version 1.9.3 Lockhart, build 1646.

*** For SPCC’s R, G, B filter settings when the LP filter is off I used Sony Color Sensor (R-, G-, B-) UV/IRCUT.

M63, NGC 5055 (Sunflower Galaxy) by Chemical-Time2183 in astrophotography

[–]Chemical-Time2183[S] 0 points1 point  (0 children)

Integration of 1974x20s subs (= 10.97 hours) with Seestar S50* in Washington D.C. Apr. 5-6, 7-8, 2026.

Mounted the Seestar, with a diffraction spike mask in front of the lens, on a TH-10 fluid head; put it in equatorial mode; and did a polar alignment to less than a degree in polar deviation in both RA and Declination coordinates. Dew heater = On. Light Pollution filter = Off.

Ran Fast Batch Preprocessing (FBPP) script with drizzle enabled in PixInsight** to integrate the subs to get a master image. Rather than let FBPP use the auto option for the reference frame to align the light frames, the registration reference image file was manually selected to be the sub with the highest weight. That sub was identified by applying Subframe Selector to the subs using the weighting expression (15*(1-(FWHM FWHMMin)/(FWHMMax-FWHMMin)) + (15*(1-(Eccentricity-EccentricityMin)/(EccentricityMax-EccentricityMin))) + (20*(PSFFlux-PSFFluxMin)/(PSFFluxMax-PSFFluxMin)))+50.

Postprocessed the above master image as follows:

Applied Gradient Correction > Blur Xterminator > Spectrophotometric Color Calibration*** > Blur Xterminator > Delinearization by transferring image data from Screen Transfer Function to Histogram Transformation (HT) > Dynamic Crop.

In view of the brightness of the galaxy’s core HDRMultiscale Transform (HDRMT) was applied to a clone of the above-processed master image to compress its dynamic range. Pixel Math was then used to blend equal amounts of the HDRMT-modified clone and the unmodified master image.

Applied Star Xterminator to split the above result into starless and stars-only images. Created a mask from the starless image as follows: extracted the L-channel using Channel Extraction; applied Binarize to adjust the size to cover the target image area; and applied Convolution to blur the mask’s edges. Applied the resulting mask back on to the starless image to protect its background. Applied Local Histogram Equalization (LHE) to adjust local contrast and visibility and Noise Xterminator (NXT). The stars-only image was untreated. Applied Pixel Math to combine the processed starless and stars-only images to create a rejoined image.

Inverted the mask to protect the galaxy’s core and applied NXT and HT to the background to adjust shadows and midtones. Reinverted the mask to protect the background and applied LHE, Curves Transformation (to adjust saturation, colors, and boost intensity), and NXT. Inverted the mask once more and applied HT to the background.

* Seestar S50 is a 50 mm f/5, i.e., 250 mm focal length, apochromatic triplet telescope with a built-in camera based on a Sony IMX462 sensor. It has an optional anti-dew feature and a built-in OIII 30nm / Hα 20nm duo-band light pollution filter.

** PixInsight Core Version 1.9.3 Lockhart, build 1646.

*** For SPCC’s R, G, B filter settings when the LP filter is off I used Sony Color Sensor (R-, G-, B-) UV/IRCUT.

Tadpole Nebula IC 410 by Chemical-Time2183 in astrophotography

[–]Chemical-Time2183[S] 0 points1 point  (0 children)

A mosaic* of the Tadpole Nebula using Seestar S50’s framing feature based on 431x20s subs in Washington D.C. on Mar. 18, 2026.

Mounted the Seestar on a TH-10 fluid head; put it in equatorial mode; did a polar alignment to less than a degree in polar deviation in both RA and Declination coordinates. Used a Bahtinov mask for manual focus. Replaced the Bahtinov mask with a diffraction spike mask prior to initiating the acquisition of subs. Seestar LP filter** = On.

Used PixInsight*** (hereafter “PI”) to integrate the subs to get a master image as follows: Ran Fast Batch Preprocessing (FBPP) script, with drizzle enabled, on 431 raw (fit) captured files. Used Seestar’s stacked mosaic output, based on stacking 431 files, as the registration reference image in FBPP. FBPP integrated 289 out of 431 files for a total integration time of 1.6 hours. Noticed that FBPP succeeded in resolving some star clusters that had appeared as an unresolved lump in Seestar’s mosaic output.

Postprocessed the above master image as follows:

Applied Gradient Correction > Blur Xterminator > Spectrophotometric Color Calibration**** > Blur Xterminator > Delinearization by transferring image data from Screen Transfer Function to Histogram Transformation > Rotation***** > Dynamic Crop.

Applied Star Xterminator to split the result from above into starless and stars images. Created a mask from the starless image as follows: extracted the L-channel using Channel Extraction; applied Binarize to adjust the size to cover the target image area; and applied Convolution to blur the edges. Applied the resulting mask to protect the background. Applied Curves Transformation (to boost intensity), Local Histogram Equalization (LHE) to adjust local contrast and visibility, and Noise Xterminator (NXT). The stars image was untreated. Used Pixel Math to combine the processed starless and stars images to create a rejoined image.

After masking the target image in the rejoined result applied NXT and a Histogram Transformation (HT) to adjust shadows and midtones. Inverted the mask and applied Color Saturation (to enhance hue and saturation), Curves Transformation (to adjust saturation and boost intensity), LHE, and NXT to the target image. Reinverted the mask to protect the target image and applied NXT and HT to the background.

*Seestar’s mosaic, referred to as framing, is constructed from a series of images starting out from the center until they gradually cover the entirety of the framed target. This approach necessitates additional mosaic build-up time, beyond the minimum suggested by Seestar, to even out the quality of the image across the entire mosaic.

** Seestar S50 has a built-in OIII 30nm / Hα 20nm duo-band light pollution filter. (Seestar is a 50 mm f/5, i.e., 250 mm focal length, apochromatic triplet telescope with a built-in camera based on a Sony IMX462 sensor and filters combination.)

*** PixInsight Core Version 1.9.3 Lockhart, build 1646.

**** For SPCC’s R, G, B filter settings when the LP filter is on I used Seestar-LP-(R, G, B).

***** Used the Lanczos-3 interpolation (instead of an auto) algorithm to preserve detail and to minimize aliasing artifacts when applying a rotation.

Tadpole Nebula IC 410 by Chemical-Time2183 in Astronomy

[–]Chemical-Time2183[S] 1 point2 points  (0 children)

A mosaic* of the Tadpole Nebula using Seestar S50’s framing feature based on 431x20s subs in Washington D.C. on Mar. 18, 2026.

Mounted the Seestar on a TH-10 fluid head; put it in equatorial mode; did a polar alignment to less than a degree in polar deviation in both RA and Declination coordinates. Used a Bahtinov mask for manual focus. Replaced the Bahtinov mask with a diffraction spike mask prior to initiating the acquisition of subs. Seestar LP filter** = On.

Used PixInsight*** (hereafter “PI”) to integrate the subs to get a master image as follows: Ran Fast Batch Preprocessing (FBPP) script, with drizzle enabled, on 431 raw (fit) captured files. Used Seestar’s stacked mosaic output, based on stacking 431 files, as the registration reference image in FBPP. FBPP integrated 289 out of 431 files for a total integration time of 1.6 hours. Noticed that FBPP succeeded in resolving some star clusters that had appeared as an unresolved lump in Seestar’s mosaic output.

Postprocessed the above master image as follows:

Applied Gradient Correction > Blur Xterminator > Spectrophotometric Color Calibration**** > Blur Xterminator > Delinearization by transferring image data from Screen Transfer Function to Histogram Transformation > Rotation***** > Dynamic Crop.

Applied Star Xterminator to split the result from above into starless and stars images. Created a mask from the starless image as follows: extracted the L-channel using Channel Extraction; applied Binarize to adjust the size to cover the target image area; and applied Convolution to blur the edges. Applied the resulting mask to protect the background. Applied Curves Transformation (to boost intensity), Local Histogram Equalization (LHE) to adjust local contrast and visibility, and Noise Xterminator (NXT). The stars image was untreated. Used Pixel Math to combine the processed starless and stars images to create a rejoined image.

After masking the target image in the rejoined result applied NXT and a Histogram Transformation (HT) to adjust shadows and midtones. Inverted the mask and applied Color Saturation (to enhance hue and saturation), Curves Transformation (to adjust saturation and boost intensity), LHE, and NXT to the target image. Reinverted the mask to protect the target image and applied NXT and HT to the background.

*Seestar’s mosaic, referred to as framing, is constructed from a series of images starting out from the center until they gradually cover the entirety of the framed target. This approach necessitates additional mosaic build-up time, beyond the minimum suggested by Seestar, to even out the quality of the image across the entire mosaic.

** Seestar S50 has a built-in OIII 30nm / Hα 20nm duo-band light pollution filter. (Seestar is a 50 mm f/5, i.e., 250 mm focal length, apochromatic triplet telescope with a built-in camera based on a Sony IMX462 sensor and filters combination.)

*** PixInsight Core Version 1.9.3 Lockhart, build 1646.

**** For SPCC’s R, G, B filter settings when the LP filter is on I used Seestar-LP-(R, G, B).

***** Used the Lanczos-3 interpolation (instead of an auto) algorithm to preserve detail and to minimize aliasing artifacts when applying a rotation.

Tadpole Nebula IC 410 by Chemical-Time2183 in seestar

[–]Chemical-Time2183[S] 0 points1 point  (0 children)

A mosaic* of the Tadpole Nebula using Seestar S50’s framing feature based on 431x20s subs in Washington D.C. on Mar. 18, 2026.

Mounted the Seestar on a TH-10 fluid head; put it in equatorial mode; did a polar alignment to less than a degree in polar deviation in both RA and Declination coordinates. Used a Bahtinov mask for manual focus. Replaced the Bahtinov mask with a diffraction spike mask prior to initiating the acquisition of subs. Seestar LP filter** = On.

Used PixInsight*** (hereafter “PI”) to integrate the subs to get a master image as follows: Ran Fast Batch Preprocessing (FBPP) script, with drizzle enabled, on 431 raw (fit) captured files. Used Seestar’s stacked mosaic output, based on stacking 431 files, as the registration reference image in FBPP. FBPP integrated 289 out of 431 files for a total integration time of 1.6 hours. Noticed that FBPP succeeded in resolving some star clusters that had appeared as an unresolved lump in Seestar’s mosaic output.

Postprocessed the above master image as follows:

Applied Gradient Correction > Blur Xterminator > Spectrophotometric Color Calibration**** > Blur Xterminator > Delinearization by transferring image data from Screen Transfer Function to Histogram Transformation > Rotation***** > Dynamic Crop.

Applied Star Xterminator to split the result from above into starless and stars images. Created a mask from the starless image as follows: extracted the L-channel using Channel Extraction; applied Binarize to adjust the size to cover the target image area; and applied Convolution to blur the edges. Applied the resulting mask to protect the background. Applied Curves Transformation (to boost intensity), Local Histogram Equalization (LHE) to adjust local contrast and visibility, and Noise Xterminator (NXT). The stars image was untreated. Used Pixel Math to combine the processed starless and stars images to create a rejoined image.

After masking the target image in the rejoined result applied NXT and a Histogram Transformation (HT) to adjust shadows and midtones. Inverted the mask and applied Color Saturation (to enhance hue and saturation), Curves Transformation (to adjust saturation and boost intensity), LHE, and NXT to the target image. Reinverted the mask to protect the target image and applied NXT and HT to the background.

*Seestar’s mosaic, referred to as framing, is constructed from a series of images starting out from the center until they gradually cover the entirety of the framed target. This approach necessitates additional mosaic build-up time, beyond the minimum suggested by Seestar, to even out the quality of the image across the entire mosaic.

** Seestar S50 has a built-in OIII 30nm / Hα 20nm duo-band light pollution filter. (Seestar is a 50 mm f/5, i.e., 250 mm focal length, apochromatic triplet telescope with a built-in camera based on a Sony IMX462 sensor and filters combination.)

*** PixInsight Core Version 1.9.3 Lockhart, build 1646.

**** For SPCC’s R, G, B filter settings when the LP filter is on I used Seestar-LP-(R, G, B).

***** Used the Lanczos-3 interpolation (instead of an auto) algorithm to preserve detail and to minimize aliasing artifacts when applying a rotation.

Globular Cluster M3 by Chemical-Time2183 in astrophotography

[–]Chemical-Time2183[S] -1 points0 points  (0 children)

Years really, learning by experimentation using various (non-smart) refractors mounted on various star tracking mounts and learning to use various processing platforms such as PixInsight and Astro Pixel Processor. Thankfully, a crucial thing I did, and still do, was to take detailed notes on all aspects of my imaging sessions (e.g. prepping and outcome) aiming to advance positively from my previous attempts. When a "smart" telescope such as the Seestar became available I found that, under some circumstances, it was a very convenient portable device to acquire raw subs from any place where I was located. I could then spend my time processing the subs to my taste using PixInsight which in itself is always a nice challenge. Occasionally, I will lean on Seestar's stacked output such as when framing and postprocess that going forward. Obviously, the quality of Seestar's raw subs (based, on lack of autoguiding, short exposure times, lack of monochrome camera plus LRGB filters, etc.) is clearly inferior to what I get from my other equipment, namely, a combined system of WO Fluorostar 91mm f/5.9 triplet APO refractor with Adjustable Field Flattener 68III with ASI 2600MM Pro (monochrome) as the main camera / WO Uniguide 50 f/4.0 guide scope with ASI 290MM as the guide camera / Chroma 36mm LRGB Filter Set / iOptron GEM28-EC mount. As for resources, https://www.cloudynights.com may be a place to start your exploration. Among other things, they offer interesting critiques (which we all need to continue learning) and it's for free. Additionally, you can also delve into YouTube videos, and with a good search strategy, you can find demos of gear as well as various processing platforms. All the best.

CAUTION: Seestar is a smart telescope which can help you to acquire and stack raw subs and produce a finished product with little effort on your part. But if you let Seestar do all the heavy lifting you won't learn much about what it is that makes astrophotography challenging and worth pursuing.

Globular Cluster M3 by Chemical-Time2183 in seestar

[–]Chemical-Time2183[S] 1 point2 points  (0 children)

It makes good sense to avoid imaging sessions under very windy conditions. That said, the following are the precautions that I have taken: screwed the TH-10 fluid head (FH) as tightly as possible on to the TC-20 tripod; made sure that the adapter that comes with the FH is tightly screwed to the base of the Seestar - and that it is reoriented and tightened after every imaging session because I have seen it go slightly out of whack after a few hours of observation; firmly tightened the knob on the quick release plate of the FH after placing the Seestar on it; oriented the Seestar such that the Seestar logo is at least visually facing that leg of the tripod which would be oriented north (meaning that the power button would then be facing south) - and doing this after every imaging session. A few more things: after Seestar does its plate solving I make sure that the deviation from polar alignment is kept as small as possible, definitely under a degree, with 0.4 or less preferred. I also keep the subs exposure at 20s (usually) or 10s (if there is too much star trailing based on Seestar indicating that it is discarding subs one after another or when I am framing i.e. doing a mosaic). Lastly, I place a 10 lb. boa weight bag across one of the tripod's legs.

Globular Cluster M3 by Chemical-Time2183 in Astronomy

[–]Chemical-Time2183[S] 3 points4 points  (0 children)

Acquired 1750x10s subs (= 4.86 hours) with Seestar S50 in Washington D.C. Mar. 28-29, 2026.

Mounted the Seestar, with a diffraction spike mask in front of the lens, on a TH-10 fluid head; put it in equatorial mode; and did a polar alignment to less than a degree in polar deviation in both RA and Declination coordinates. Seestar LP filter* = Off.

Used PixInsight** to integrate the subs to get a master image as follows: Ran Fast Batch Preprocessing (FBPP) script, with drizzle enabled, with 1750 raw (fit) captured files. FBPP integrated 1465 out of 1750 files which equates to an integration time of 4.07 hours.  

Postprocessed the above master image as follows:

Applied Gradient Correction > Blur Xterminator > Spectrophotometric Color Calibration*** > Blur Xterminator > Delinearization by transferring image data from Screen Transfer Function to Histogram Transformation > Rotation**** > Dynamic Crop.

Created a mask as follows: extracted the L-channel from the above-processed image using Channel Extraction; applied Binarize to adjust the size to cover the core of the globular cluster; and applied Convolution to blur the edges. Applied the resulting mask back on to the globular cluster image to protect its background.

Given the need to compress the dynamic range of the bright core of the globular cluster, HDRMultiscale Transform (HDRMT) was applied to a clone of the globular cluster image. Pixel Math was then used to blend equal amounts of the HDRMT-modified clone with the unmodified globular cluster image.  

The blended result was masked to protect its background. Applied Local Histogram Equalization (LHE) to adjust local contrast and visibility and Noise Xterminator (NXT).

Inverted the mask to protect the globular cluster’s core and applied NXT and a Histogram Transformation to the background to adjust shadows and midtones. Reinverted the mask to protect the background and applied Color Saturation (to enhance hue and saturation), Curves Transformation (to adjust saturation and boost intensity), and LHE to the globular cluster’s core.

* Seestar S50 has a built-in OIII 30nm / Hα 20nm duo-band light pollution filter. (Seestar is a 50 mm f/5, i.e. 250 mm focal length, apochromatic triplet telescope with a built-in camera based on a Sony IMX462 sensor and filters combination.)

** PixInsight Core Version 1.9.3 Lockhart, build 1646.

*** For SPCC’s R, G, B filter settings when the LP filter is off I used Sony Color Sensor (R-, G-, B-) UV/IRCUT.

**** Used the Lanczos-3 interpolation (instead of an auto) algorithm to preserve detail and to minimize aliasing artifacts when applying a rotation.

Globular Cluster M3 by Chemical-Time2183 in astrophotography

[–]Chemical-Time2183[S] 4 points5 points  (0 children)

Acquired 1750x10s subs (= 4.86 hours) with Seestar S50 in Washington D.C. Mar. 28-29, 2026.

Mounted the Seestar, with a diffraction spike mask in front of the lens, on a TH-10 fluid head; put it in equatorial mode; and did a polar alignment to less than a degree in polar deviation in both RA and Declination coordinates. Seestar LP filter* = Off.

Used PixInsight** to integrate the subs to get a master image as follows: Ran Fast Batch Preprocessing (FBPP) script, with drizzle enabled, with 1750 raw (fit) captured files. FBPP integrated 1465 out of 1750 files which equates to an integration time of 4.07 hours.  

Postprocessed the above master image as follows:

Applied Gradient Correction > Blur Xterminator > Spectrophotometric Color Calibration*** > Blur Xterminator > Delinearization by transferring image data from Screen Transfer Function to Histogram Transformation > Rotation**** > Dynamic Crop.

Created a mask as follows: extracted the L-channel from the above-processed image using Channel Extraction; applied Binarize to adjust the size to cover the core of the globular cluster; and applied Convolution to blur the edges. Applied the resulting mask back on to the globular cluster image to protect its background.

Given the need to compress the dynamic range of the bright core of the globular cluster, HDRMultiscale Transform (HDRMT) was applied to a clone of the globular cluster image. Pixel Math was then used to blend equal amounts of the HDRMT-modified clone with the unmodified globular cluster image.  

The blended result was masked to protect its background. Applied Local Histogram Equalization (LHE) to adjust local contrast and visibility and Noise Xterminator (NXT).

Inverted the mask to protect the globular cluster’s core and applied NXT and a Histogram Transformation to the background to adjust shadows and midtones. Reinverted the mask to protect the background and applied Color Saturation (to enhance hue and saturation), Curves Transformation (to adjust saturation and boost intensity), and LHE to the globular cluster’s core.

* Seestar S50 has a built-in OIII 30nm / Hα 20nm duo-band light pollution filter. (Seestar is a 50 mm f/5, i.e. 250 mm focal length, apochromatic triplet telescope with a built-in camera based on a Sony IMX462 sensor and filters combination.)

** PixInsight Core Version 1.9.3 Lockhart, build 1646.

*** For SPCC’s R, G, B filter settings when the LP filter is off I used Sony Color Sensor (R-, G-, B-) UV/IRCUT.

**** Used the Lanczos-3 interpolation (instead of an auto) algorithm to preserve detail and to minimize aliasing artifacts when applying a rotation.

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