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.

Date04. 12. 2002
TimeSecond contact: 06:18:26 UT, third contact 06:19:34 UT
Eclipse duration 1 min 8 s
PlaceSouth Africa, Messina, High School Eric Louw
Coordinate30° 00' E, 22° 23' S, altitude approx. 1500 m
ConditionsGood, in the end of totality thin clouds
OpticsZeiss 10/1000 mm
Resolution6.48 arc sec / pixel (image on this Web page)
FilmFujicolor Reala 100
Processing16 different images were used for image creation. Images were aligned by means of phase correlation technique and then processed using Corona 3.0 software. Isolines and final processing were done by ACC 6.0 image analyser.
Image processing by Miloslav Druckmüller
ScannerNikon Super Coolscan 4000 ED (4000dpi, 16× multisample)
SoftwarePhaseCorr 3.0, Corona 3.0, Sofo ACC 6.0
NoteYellow circle inside the Moon represents exact position of the photosphere edge.
OrientationImage must be rotated 6.4° clockwise to achieve the standard orientation (N top, E left)
Copyright© 2004 Vojtech Rušin, Miloslav Druckmüller


Miloslav Druckmüller
Institute of Mathematics, Faculty of Mechanical Engineering
Brno University of Technology, Czech Republic
Page last update: 19.3.2007