A ceramic arctube for use in a high intensity discharge lamp. The arctube includes a ceramic light transmitting tube which surrounds the arc. The light transmitting tube has two or more features selected from the group consisting of (a) an inner diameter less than 2.6 mm, (b) a wall thickness of less than 1.4 mm, (c) an average grain size of greater than 20 microns or less than 5 microns or real in-line transmission (RIT) greater than 20 %, and (d) an inner surface or outer surface having an Ra value less than 100 nm. These features lead to a smaller apparent size of the arc source and less scattering of light, resulting in improved performance of the arctube in a reflector lamp.