Geometrical effects on image contrast in photoelectrochemical microscopy, where the image is developed as a consequence of the temperature transient induced by a rapidly scanned, focused laser spot, were explored using gold microband and disc electrodes and the Fe (CN)(6)(3-)/Fe (CN)(6)(4-) redox couple. The photocurrent signal obtained on a line electrode was much less than that on a disc. The signal was also very sensitive to poisoning of the surface causing the electrode reaction to become irreversible.