Two sets of photographs were used for creation of images presented on this page. The first
set consists of color slides and it was taken in Chile by Vojtech Rušin. The inner corona is very
well recorded on these slides but only up to the distance of about 0.7 solar radii. The outer part
of corona was fortunately well recorded by Úpice observatory expedition led by Eva Marková. They took
set of B&W images which I used to improve contrast in the distant part of corona. The most critical
step of processing was precise alignment of images with different scale and orientation. These alignment
was done by means of phase correlation technique based on Fourier transform. The time delay between the
sets of images was rather long - about 23 minutes but in the outer part of corona there were no features
which could to be supposed fast moving. Therefore the composition of both sets of images didn't cause
resulting image blurring.
Note: If any page needs more than 100 KB to be downloaded, there exists its lower quality version appointed for slow connection.
Page last update: 5.6.2007