The reflectance of high-quality, unpolished single crystals of YBa 2 Cu 3 O 6 + x , for the doping range x = 0.50 -> 0.95, has been measured with radiation polarized along the c-axis from ~ 50 cm - 1 to 5000 cm - 1 between 10 K and 300 K. In highly doped (x = 0.95) material, the normal-state conductivity shows a metallic response. For intermediate dopings (x = 0.85 -> 0.90) the conductivity is no longer metallic, increasing with temperature, and for low dopings (x = 0.50 -> 0.80) this behavior is clearly seen to be caused by a broad pseudogap at ~ 290 cm - 1 , which develops well above T c . In the superconducting state, in the optimally doped material, a gap-like depression develops below T c but there is residual conductivity to very low frequency indicating either an anisotropic gap, or a gap with nodes. In the underdoped materials the superconductivity-induced changes to the conductivity are harder to see, but it appears that the weight of the condensate originates at frequencies much higher than the conventional weak-coupling BCS value of 3.5k B T c .