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.
Click on the following reference to display the same image in the maximum quality (913 KB, PNG format).

Date11. 08. 1999
TimeSecond contact 10:50:37 UT, third contact 10:53:00 UT
Total eclipse duration 2 min 23 s
PlaceHungary, 2 km SSE from Németkér village
CoordinateN 46° 41' 36'', E 18° 47' 14''
ConditionsExcellent, clear sky. (Solar altitude 59° above horizon)
OpticsMaksutov - Cassegrain MTO 1000a, 10.5/1084mm and Sonnar 2.8/200mm
Resolution17.3 arc sec / pixel (image on this Web page)
FilmFujicolor Superia 800 (for MTO), Agfacolor HDC 400 Plus (for Sonnar)
ProcessingAdaptive processed composition of 27 images (6 taken with Sonnar, 21 taken with MTO) with brightness isolines overlay
Image processing by Miloslav Druckmüller
ScannerNikon Super Coolscan 4000 ED (4000dpi resolution, 16× multisample)
SoftwareSofo ACC 6.0, Corona 3.0, PhaseCorr 3.0
OrientationThe image must be rotated 11.8° clockwise to achieve the standard orientation i.e. North top, East left
More infoComplete set of processed images and animation including many texts about Sun and solar eclipses was published on multimedia CD: Miloslav Druckmüller, Journey to Solar Eclipse, AION and WOLF RECORDS, 2000
Copyright© 2004 Hana Druckmüllerová and Miloslav Druckmüller


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