Laserdiscs

Advocates of laserdiscs contend that the LD format holds numerous advantages over the widely prevalent DVD format. DVDs employ digital video etching. In other words, sound and optical signals are translated into binary form and then coded onto the surface of DVD discs. While this encoding allows for a certain degree of homogeneity, it can also compromise the natural quality of the images and sounds.

Laserdiscs, on the other hand, employ analog signal coding. Sounds and images get etched directly onto the surface of LDs as microscopic grooves, pits, and hills. Optimized LDs, therefore, can produce higher-quality pictures and sound than optimized DVDs. Moreover, LDs don't suffer from artifacting, encoding troubles, and color bending like DVDs do.

This is not to say that laserdiscs are ideal, either. Laserdiscs are hefty--30 cm in diameter. You can buy laserdisc players which flip discs in the middle of play, but these players tend to be really expensive. Since LDs use wide-wavelength lasers, they occasionally produce an unwanted visual effect called "crosstalk," in which multiple frames get displayed on the monitor at once.

Record companies and movie studios no longer release major LD offerings. However, despite the market superiority of DVDs, laserdiscs have inspired passionate collectors groups worldwide. The very lack of new LD production has made laserdiscs already in circulation that much more valuable. Always check for "laser rot" (oxidation) when shopping for LDs--the LD release of the movie Eraser, for instance, contained numerous instances of laser rot.