Acquired 946x20s subs (= 5.25 hours) with Seestar S50 in Washington D.C. Mar. 20, 2026.
Mounted the Seestar 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. Used a Bahtinov mask for manual focus. Replaced the Bahtinov mask with a diffraction spike mask prior to acquiring subs. 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, on 946 raw (fit) captured files. FBPP integrated 932 out of 946 files for a success rate of 98.5% of the captured raw subs.
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 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.
Applied the mask on the rejoined result to protect the target image 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) and Curves Transformation (to adjust saturation and boost intensity). Completed postprocessing by applying LHE to the target image.
* 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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Acquired 946x20s subs (= 5.25 hours) with Seestar S50 in Washington D.C. Mar. 20, 2026.
Mounted the Seestar 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. Used a Bahtinov mask for manual focus. Replaced the Bahtinov mask with a diffraction spike mask prior to acquiring subs. 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, on 946 raw (fit) captured files. FBPP integrated 932 out of 946 files for a success rate of 98.5% of the captured raw subs.
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 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.
Applied the mask on the rejoined result to protect the target image 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) and Curves Transformation (to adjust saturation and boost intensity). Completed postprocessing by applying LHE to the target image.
* 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.