| | By Jim Ames To help you decide about which system to use with your home improvements, here is some information on the two formats, Blu-ray and HD-DVD, plus some pros and cons of each. Ordinary CDs and DVDs use a laser that produces red light (whose wavelength is about 650nm, a little more than half a micron). Blu-ray and HD-DVD units use a blue-light laser, with wavelength of 405nm (a little less than half a micron). |