Degradation of images of astronomical objects during observations with large optical telescope may be described as combination of atmosphere turbulence on a time scale shorter than some tenths of a second and random fluctuation of object’s position due to telescope and observer’s guiding errors, bending of construction under external factors (wind, etc.). Special investigations on the 6-meter telescope (Balega, 1989) showed, that the peak frequency of such low-frequency fluctuations is located near 1 Hz.

The method of Time Resolving Image Mode, developed by J.-L.Nieto et al (1987) for post-detection improvement of angular resolution at CFHT, showed that, even in places with excellent quality of atmosphere, the resolution of large telescope may be increased by 20-30% only, although powerful methods of image recentering and frames selection were performed. Moreover, such method of data processing may be applied to relatively bright objects only. For 6-meter telescope, resolution improvement would be useless at all due to smaller Fried parameter and larger main mirror.