Gamma_per.mpg from:
http://op.ph.ic.ac.uk/speckle/movies.html

Data from the William Herschel 4.2 metre Telescope in La
Palma.

The data was taken with a simple Speckle Camera situated on the GHRIL platform of the telescope. The
recording system was a Tektronics CCD camera, with a Princeton Instruments controller transmiting data to a
Sun workstation. 
The data sets were taken on the nights of January 17th & 18th 1995, in collaboration with the Speckle
Imaging group at Cardiff University. 
Gamma Perseus, 0.2 arcsecond binary. 250 frames). 
          Wavelength 570nm, Exposure time 25ms per frame , 200x200, 12.5arsec/pixel (775kbytes). 

from http://op.ph.ic.ac.uk/speckle/speckle.html
The relatively recent development of speckle imaging, and related interferometric techniques, allows
the full resolving power of a large telescope to be reclaimed. This involves the collection of a large number of
short (~few ms) exposures of the astronomical object of interest which, unlike conventional astronomical
images, retain diffraction limited information. From these the average power spectrum and average bispectrum
are calculated and, after calibration by a reference source which removes the effects of atmospheric turbulence
- along with telescope aberrations, the object Fourier spectrum can be extracted and Fourier inverted to
obtain an image.