Brightness isolines

Adaptive filters used to visualize coronal structures (Corona 3.0 software) enable to create images very near to human vision sensation during eclipse but they cause loss of information about absolute image brightness. This information itself is not of big value if the image is only observed on computer screen because the human vision has very poor ability to estimate absolute brightness. This information can be added to the image in the way easily understandable for human vision by constructing of brightness isolines. It makes possible to study the corona shape from the point of brightness distribution.

Date22. 07. 1990
TimeSecond contact 03:03:06 UT, third contact 03:04:50 UT
Eclipse duration 104 s
PlaceRussia, Chukotka, Markovo village near Anadyr river
CoordinateE 170° 30' , N 64° 43'
ConditionsGood - altitude of the Sun 41° above the horizon
OpticsMerz 160 mm stopped down to 90 mm, focal length 1785 mm
FilmFortepan 400
Exposure1/125 s - 2 s
ProcessingSum of 7 images enhanced by means of adaptive kernel convolution. The original images are B&W, the color is added by image processing.
Image processing by Miloslav Druckmüller
ScannerNikon LS 8000 (4000dpi resolution, 16 bit/pixel)
SoftwareSofo ACC 6.0 Scientific Image Analyzer with Match II Module (isolines computing and final processing)
Corona 3.0 (coronal structure enhancement)
PhaseCorr 2.0 (rotation estimation - registration of images)
OrientationThis image has the standard orientation i.e. North on the top end East on the left
Copyright© 1990 Úpice Observatory, © 2004 Miloslav Druckmüller


Miloslav Druckmüller
Institute of Mathematics, Faculty of Mechanical Engineering
Brno University of Technology, Czech Republic
Page last update: 18.3.2007