White-light observations were carried out during the eclipse of July 11, 1991, at Big Bear Solar Observatory. The images were obtained by the 65 cm reflector with the OSL CCD camera. The lunar limb was always included in the field of view. We derived the one-dimensional point spread function (PSF) of seeing, which includes degradation by the telescope from the smeared lunar limb profile. The width of the PSF is between 0.8 to 1.3 arcsec on that day. Assuming cylindrical symmetry, we obtained the two-dimensional PSF. We then used the seeing function to deconvolve the observed white-light images. The reconstruction method enhances the observed 5% value of rms contrast to 18%; light bridges may be brighter than the normal photosphere; dark penumbra fibrils could be as dark as 50% of normal photosphere while the bright fibrils could reach the brightness of normal photosphere.
All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science
- Image reconstruction
- eclipse observation