Processing Example


by Alejandro Tombolini


Image of the conjuntion between Venus, Moon, Jupiter and Regulus. Processing of a single frame. Main notes: Stretch with MaskedStretch. Non linear postprocessing with help of a mask made with RangeSelection tool. Date: July 2015.

Image Details

  • Object: Venus, Jupiter, Regulus and Moon
  • Camera: Canon 5DIII - Filter Type I
  • Telescope: Canon Lens - EF 24-105L in 58 mm - f/22,6
  • Images: 1 x 1,61 seconds. ISO 1600
  • Total time: 1,61 seconds.
  • Processing Program: PixInsight
  • Comments: Sunset with coluds. From Trenel, La Pampa, Argentina. Without guiding.
  • Author: Alejandro Tombolini


Open the image and as my DSLR Settings are Pure Raw it is uploaded into the workspace without debayer.  This single image with short exposure time do not have hot pixels, so I will process it without calibration.
First debayer the image using Debayer tool with values by default.

To solve a slight vignetting I use DynamicBackgroundExtraction tool placing the samples where are the main darker areas independently from sky gradient and select Division as correction of the image.

Select a preview that represent the background of the sky and limit lower an upper values in BackgroundNeutralization tool.

Stretch the image using MaskedStretch tool. Use the same preview as background reference adjusting the upper limit and set the Clipping fraction conveniently to achieve a good contrast in the stretched image.

I will build a mask using RangeSelection tool to protect darker areas of the images during saturation, to avoid the noise increase in low SNR areas. Moving Fizziness to 1 almost gives the needed mask and finally increase the smoothness to adjust the protection in the Moon.

Saturation increase chrominance noise, then use ACDNR tool to noise reduction yet  protecting the image with range mask.

More contrast with LocalHistogramEqualization tool.

Some areas between the trees can be highlighted increasing Bias in MultiscaleLinearTransform tool.

As I did not use flats, there is a remaining dark mote that I will remove with ConeStamp tool.

Finally a little of noise reduction using MultiscaleLinearTransfrom.

Resample for web publication

Add signature using DrawSignature script.

Final Image

Last Update: 27/11/2023 03:43 UT