We have characterized the homogeneity of large-area ( $>10mm\times 10mm$ ) $\mathrm{Cd}\mathrm{Te}(110)$ and $\mathrm{Zn}\mathrm{Te}(110)$ crystals using a raster electro-optic scanning method to assess their usability in two-dimensional electro- optic terahertz (THz) imaging with parallel read out. The spatial variation in the detected THz signal (at 0.2 and $0.645\mathrm{THz}$ , respectively) is due to nonuniform residual birefringence and scattering. For CdTe, this depends critically on the growth method, and has an important contribution from slip planes in the crystals, as is evident in the scanned images. For the highest-quality $\mathrm{Cd}\mathrm{Te}(110)$ crystals investigated, the rms signal variations are less than 15%, comparable to those for $\mathrm{Zn}\mathrm{Te}(110)$ . For electro-optic scanning, we introduce a hybrid measurement system based on a fs Nd:glass laser and a continuous-wave elec tronic THz source.