Umbral dots (UDs) were observed using the 1.6 meter solar telescope. Achieved conventional diffraction limit in the TiO 705.68 nm spectral line used was 0ŭ1. The 418 UDs were analysed. Median diameter was 0ŭ5 and median intensity difference between darkest part of the UD's background and brightest part of the UDs was 37%. Despite the achieved resolution, no UDs substructures were visible. The analysed UDs appeared to be circular.