Comet Neowise and dunes (reprocessed) (Firooz Amjadi)

Comet Neowise and dunes (reprocessed)

Description
The unusual cropping was done to display the whole image composition at low and medium enlargements. To get a much sharper image, view at full resolution and scroll to the right.

For whatever reason, the displayed image quality at low and medium enlargement is not very good. This is the opposite of what one may expect!

I initially posted this in 2020, but I thought the processing was not very good. After 2 years of practicing I decided to reprocess the image again with hopefully better results.

The sky was tracked using 9 frames. The sensor of the camera was shifted between each image. The Pentax k-1 allows manual shifting of the sensor between images. This is essentially in camera dithering to correct hot and slow and dead pixels. Each panel was manually stacked and blended using median mode.

The lens was disassembled and modified with a fixed circular aperture at f5.6 to eliminate diffraction spikes and minimize distortion of stars and provide 100% illumination and very sharp stars across a full frame sensor.

The foreground was captured using 3 images focused at different focus points and manually aligned and blended to keep the near sand and far dunes in sharp focus.

The sky and the foreground were manually blended . This allowed a relatively high dynamic range image to preserve detail both in the sky and some detail in the foreground.

Many masks were used to preserve as much detail in the comet as possible. Initially the stars were removed to allow processing and later added back in the image.

Also many gradient filters were used to minimize the orange color on the horizon.

I welcome critical comments to improve my work in the future.

Technical:

Camera: Pentax K-1

Mount: Celestron AVX

Lens: Rokinon 135mm F2 with a modified circular aperture @ F5.6

ISO: 3200 for sky

Exposure: 120 sec. for sky

Polar alignment: Sharpcap

Software: Photoshop CS6

	Distinct awarded users	Total awarded images
Image of the day
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	Image of the day	Top pick	Top pick nominations	Total submitted
Deep sky
Solar system
Extremely wide field
Star trails
Northern lights
Noctilucent clouds
Landscape

	Image of the day	Top pick	Top pick nominations	Total submitted
Backyard
Traveller
Own remote observatory
Amateur hosting facility
Public amaeteur data
Professional, scientific grade data
Mix of multiple sources
Other
Unknown

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Status	Basic failed
Started	...
Astrometry.net job	7112551
PixInsight job	n/a
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