Application of discharge plasma for flow control became one of the most rapidly developing problems in aerodynamics. The most promising type of discharge is the nanosecond sliding dielectric barrier discharge (SDBD). In this paper, the integral images of SDBD obtained in synthetic air and in pure nitrogen at pressures from 75 up to 750 torr are presented. SDBD is shown to be more homogeneous in pure nitrogen than in synthetic air. It is also shown that discharge homogeneity increases with decreasing pressure.