We present new narrow-band H$\alpha$ imaging from the Hubble Space Telescope of two z=0.91 galaxies that have been lensed by foreground galaxy cluster Abell 2390. These data provide a magnified look at the morphology of star formation at an epoch when the global star formation rate was still high.  We discuss the source-plane morphologies of these galaxies in relation to their kinematics and compare the distribution of star formation as traced by H$\alpha$ to the broad-band colors at 285 nm, 418 nm, and 653 nm in the rest-frame of the galaxies. In particular, we measure the spatial extent of the H$\alpha$ emission and compare this to the extent of the underlying old stellar population at 653 nm, giving us insight into the locations of both past and current star formation in these galaxies. Finally, we relate star formation rates measured from the continuum subtracted H$\alpha$ image to those from the rest-285 nm emission and the mid- to far-infrared spectral energy distributions from Spitzer and Herschel, and use these to estimate and discuss the effects of extinction.