A reworking of the image using new PixInsight tools. In this rendering I've used the SpectrophotometricColorCalibration process to colour correct the image based on a transmission curve I've created for the Triad Quad Ultra Filter to represent my sensor/filter combination. Note that in the end I did tweak the colour somewhat using CurvesTransforation.

NGC 2175 (also known as the Monkey Head Nebula) is an H II emission nebula located in the constellation Orion and is associated with the open star cluster NGC 2175 which is also shown in this image. It is thought to be located about 6,400 light-years away from Earth. The visual magnitude is 7.59.

Note: click on the image to view it at the full resolution of the uploaded image, then click again for actual size.

Exposure	55@1200 sec (18.33 hours)
ISO	3200
Camera	Nikon Z7 [8856 x 5504]
Optics	Skywatcher Esprit 120mm Refractor, 840 mm focal length
Filter	Radian Triad Ultra Quad-Band Narrowband Filter
Guiding	Phd2 using a ZWO 224MC on an Orion 60x240mm Guide scope
Controller	Images taken using Kstars on an Odroid-N2 (Raspberry Pi clone)
Location	Lower Sackville, Nova Scotia.
Date	2022-03-27 and earlier sessions
PixInsight Processing	WeightedBatchPreprocessing Script Dynamic Crop Dynamic Background Extraction Image Solver Script SpectrophotometricColorCalibration BlurXTerminator NoiseXTerminator GeneralizedHyperbolicStretch BlurXTerminator CurvesTransformation

Date: March 26, 2025 ]]> https://sciencedowneast.com/zenphoto/index.php?album=Nebulae/Monkey-Head-Nebula&image=NGC-2175-Monkey-Head-Nebula-2023-09-16.jpg Wed, 26 Mar 2025 17:50:04 -0300 https://sciencedowneast.com/zenphoto/index.php?album=Nebulae/Monkey-Head-Nebula&image=masterLight_BIN-1_EXPOSURE-1200.00s_FILTER-LPR_RGB_3-3.jpg Click on the image to view it at full resolution,
then click again for actual size.

NGC 2175 (also known as the Monkey Head Nebula) is an H II emission nebula located in the constellation Orion and is associated with the open star cluster NGC 2175 which is also shown in this image. It is thought to be located about 6,400 light-years away from Earth. The visual magnitude is 7.59.

Exposure	55@1200 sec (18.33 hours)
ISO	3200
Camera	Nikon Z7 [8856 x 5504]
Optics	Skywatcher Esprit 120mm Refractor, 840 mm focal length
Filter	Radian Triad Ultra Quad-Band Narrowband Filter
Guiding	Phd2 using a ZWO 224MC on an Orion 60x240mm Guide scope
Controller	Images taken using Kstars on an Odroid-N2 (Raspberry Pi clone)
Location	Lower Sackville, Nova Scotia.
Date	2022-03-27 and earlier sessions
PixInsight Processing	WeightedBatchPreprocessing Script Dynamic Crop MultiscaleLinearTransform HistogramTransform CurvesTransformation EX Star Reduction
Further tweaking in Lightroom

Date: March 26, 2025 ]]> https://sciencedowneast.com/zenphoto/index.php?album=Nebulae/Monkey-Head-Nebula&image=masterLight_BIN-1_EXPOSURE-1200.00s_FILTER-LPR_RGB_3-3.jpg Wed, 26 Mar 2025 17:50:04 -0300 https://sciencedowneast.com/zenphoto/index.php?album=Nebulae/Monkey-Head-Nebula&image=NGC_2175_Monkey_Head_Nebula.jpg Click on the image to view it at full resolution,
then click again for actual size.

NGC 2175 (also known as the Monkey Head Nebula) is an H II emission nebula located in the constellation Orion and is associated with the open star cluster NGC 2175 which is also shown in this image. It is thought to be located about 6,400 light-years away from Earth. The visual magnitude is 7.59.

Exposure	55@1200 sec (18.33 hours)
ISO	3200
Camera	Nikon Z7 [8856 x 5504]
Optics	Skywatcher Esprit 120mm Refractor, 840 mm focal length
Filter	Radian Triad Ultra Quad-Band Narrowband Filter
Guiding	Phd2 using a ZWO 224MC on an Orion 60x240mm Guide scope
Controller	Images taken using Kstars on an Odroid-N2 (Raspberry Pi clone)
Location	Lower Sackville, Nova Scotia.
Date	2022-03-27 and earlier sessions
PixInsight Processing	WeightedBatchPreprocessing Script Dynamic Crop MultiscaleLinearTransform HistogramTransform CurvesTransformation
Further tweaking in Topaz DeNoise

Date: March 26, 2025 ]]> https://sciencedowneast.com/zenphoto/index.php?album=Nebulae/Monkey-Head-Nebula&image=NGC_2175_Monkey_Head_Nebula.jpg Mon, 28 Mar 2022 21:30:54 -0300 https://sciencedowneast.com/zenphoto/index.php?album=Nebulae/Monkey-Head-Nebula&image=NGC_2174-integration_DBE_DBE_clone-3.jpg Click on the image to view it at full resolution,
then click again for actual size.

NGC 2175 (also known as the Monkey Head Nebula) is an H II emission nebula located in the constellation Orion and is associated with the open star cluster NGC 2175 which is also shown in this image. It is thought to be located about 6,400 light-years away from Earth. The visual magnitude is 7.59.

Exposure	15@1200 sec (5 hours)
ISO	800
Camera	Nikon Z7 [8856 x 5504]
Optics	Skywatcher Esprit 120mm Refractor, 840 mm focal length
Filter	Radian Triad Ultra Quad-Band Narrowband Filter
Guiding	Phd2 using a ZWO 224MC on an Orion 60x240mm Guide scope
Controller	Images taken using Kstars on an Odroid-N2 (Raspberry Pi clone)
Location	Lower Sackville, Nova Scotia.
Date	2021-01-15
PixInsight Processing	WeightedBatchPreprocessing Script Dynamic Crop Automatic Background Extractor ColourCalibration (both saturation and hue) MultiscaleLinearTransform HistogramTransform CurvesTransformation
Further tweaking for colour in Lightroom

Date: March 26, 2025 ]]> https://sciencedowneast.com/zenphoto/index.php?album=Nebulae/Monkey-Head-Nebula&image=NGC_2174-integration_DBE_DBE_clone-3.jpg Sat, 16 Jan 2021 16:48:05 -0400