We present the first images of galactic HI absorption seen against two background quasars made with 100-au resolution. The two quasars, 3C 138 and 3C 147, are compact steep-spectrum sources with angular sizes of around 1.5 arcsec. Two prominent spectral features are observed for both quasars. Their positions are 10 deg above and below the galactic plane. Both sources show significant variations in the optical depth of hydrogen but in one of the two lines only. In one case the variation is in the high optical depth line and in the other it is in the low optical depth line. An explanation for these variations is given based on fractal structure within a clumpy HI cloud.