BD-R LTH (Low To High)
BD-R LTH is a write-once Blu-ray disc format that features an organic dye recording layer.
The advantage of BD-R LTH is it can protect a manufacturer's investment in DVD-R/CD-R manufacturing equipment. Only modifications are required to current equipment; no investment in new production lines is required. It is believed this can lower the cost of discs.
Old Blu-ray players and recorders can't utilize BD-R LTH, however, a firmware upgrade could enable the device to access BD-R LTH. Panasonic has already released such a firmware update in November 2007 for its DMR-BW200, DMR-BR100 and the MR-BW900/BW800/BW700 models.
Pioneer is also expected to ship the first LTH BD drives in Spring of 2008. Furthermore, Sony's PlayStation 3 received firmware upgrade to enable BD-R LTH reading in March, 2008.