PixInsight on L'Arciere Celeste

Enhance HII regions in Spiral galaxies

Sun, 12 Apr 2015 19:59:11 +0000

Galaxies are among the most fascinating objects to be photographed, their light emission comes mainly from the stars so it has a continuum spectrum.

For this reason, the primary capture method with CCD cameras is through RGB broadbandfilters ot get true-color images.

Some spiral galaxies, however, are very rich in HII regions, areas in which star formation is particularly active, and emit mainly hydrogen spectrum whose main emission line in the visible, called Hα (H alpha), is in red at 656.28 nm.

Correcting bias drift through overscan calibration

Fri, 12 Aug 2022 15:01:50 +0000

Page translated by Claude — switch to Italian to read the original article.

Image calibration is a crucial step during the pre-processing of astronomical images; this short article takes a closer look at the calibration of cameras that suffer from the phenomenon known as bias drift, thanks to calibration using the overscan area.

New PixInsight Script: LinearStarNet

Sat, 02 Jan 2021 20:23:13 +0000

Warning! This article is now out of date and no longer applicable. Neural network-based tools can now handle both linear and nonlinear images perfectly, so LinearStarnet is no longer distributed.

StarNet++ is a very interesting project by Mikita Misiura.

It’s a neural network based software to remove stars from astronomical images, and it does surprisingly well.

PixInsight Script: Correct magenta stars

Wed, 02 Oct 2019 22:38:45 +0000

Leggilo in italiano

Thanks to the collaboration with Roberto Sartori here our first PixInsigth script.

to be honest there is very little of me in it, only the “technical direction”, the programming part was done entirely by Roberto.

The script is used to quickly and effectively correct the problem of magenta halos that appear around the stars when the narrow band images are combined to form the so-called Hubble Palette.

Processing comet images

Sun, 16 Sep 2018 19:03:43 +0000

Page translated by Claude — switch to Italian to read the original article.

In this video tutorial it will be explained how to process comet images so as to obtain the image of the comet stationary among the stars.

The starting data are a series of shots taken by my friend Emmanuele Sordini (http://www.bloomingstars.com/?lang=it) using a Baader-modified Canon EOS 6D mounted on a Pentax 75 SDHF.

When BatchPreprocessing fails.

Sat, 17 Feb 2018 13:32:59 +0000

Page translated by Claude — switch to Italian to read the original article.

This tutorial, created by Edoardo Luca Radice and Vittorio Liberti of the Astrofili Veneti (http://www.astrofiliveneti.it/), aims to analyze and solve one of the possible problems that could be encountered when using PixInsight’s BatchPreprocessing with the Default values.
Using BatchPreprocessing with the default values, the final result was the following (as an example, only the image obtained with the SII filter is used).

Video guide: ScreenTransferFunction and HistogramTransformation

Sat, 17 Feb 2018 13:25:54 +0000

Page translated by Claude — switch to Italian to read the original article.

An extremely simple introductory video on the use of PixInsight’s basic tools:
ScreenTransferFunction
HistogramTransformation
CurvesTransformation

Designed for black-and-white images

Video guide: processing NGC 891

Tue, 30 May 2017 11:44:40 +0000

Page translated by Claude — switch to Italian to read the original article.

During the “brainstorming” session of the PixInsight Workshop at the Torre del Sole on May 27 and 28, 2017, I was asked for advice on how to process an image of NGC 891

The image is an LRGB capture taken from the city sky of Manerbio by my friend Alberto Crescenti.

LRGB composition in the linear stage with PixInsight

Tue, 14 Mar 2017 22:38:08 +0000

Page translated by Claude — switch to Italian to read the original article.

INTRODUCTION

N.B. The procedure described below is still experimental and may not give the hoped-for results.

At the moment it seems to work quite well on images of objects with broadband emission (galaxies, star clusters) while it gives inconsistent results on narrowband-emission objects.

Any comment will be useful to improve the procedure: contact me at my email address or through the Facebook group "PixInsight Italia"

In recent years, astronomical photography with “aesthetic” purposes has spread widely among enthusiasts thanks to the advent of increasingly sensitive electronic sensors at affordable prices.

The Astro Imaging Channel: Challenge nr 1

Wed, 17 Jun 2015 20:56:08 +0000

On Monday June 22nd 2015 The Astroimaging Channel proposed an image processing challenge (read here) based on a set of RGB images of the Markarian chain.

This was the challenge:

1. Gradient Removal while preserving star color.
A few months back, I wanted to try imaging my blue channel high up in the sky. It didn’t work out as planned and I have a terrible gradient through the image. I’ve been able to get rid of the gradient, but it leaves a bad color cast through my stars. The challenge is to remove the gradient and preserve the star color.

Narrowband color composition using J-P Metsavainio Tone Map technique in PixInsight 1.8

Fri, 17 Oct 2014 12:24:49 +0000

Leggilo in Italiano

Recently I began to take astronomical pictures in narrow band using my SBIG ST2000XM and a set of Baader Filters (Hα, Hb, OIII and SII).

One of the most famous color composition technique of narrowband data is the Hubble Palette that gives to nebulas a typical golden-turquoise color palette.
In this composition the SII emission is associated to Red, OII to Blue and H alpha to Green.
The drawback of this composition is that, since Hα widely dominates on OIII and SII emission, OIII and SII image histograms should be boosted relative to Hα, this bloats stars and creates weird magenta halos.