: HDLight . This is a specific encoding style designed to maintain high-definition visual quality while significantly reducing file size compared to a standard Blu-ray rip.
: This is a common label used by release groups to indicate a highly compressed, high-quality encode optimized for storage and streaming. It's not a formal standard but a widely understood term among enthusiasts. The goal is to find the "sweet spot" where the file size is small, but the picture remains crisp, colors are accurate, and there are no visible compression artifacts like blocking or banding. sherlocks02multi1080pblurayhdlightx265h4s5s link
: This is the "tag" of the release group or encoder responsible for ripping and compressing the files. Why Season 2 is a Fan Favourite : HDLight
Historically, encoding a 90-minute episode in 1080p Blu-ray quality using older codecs (like x264 or Xvid) would result in massive files ranging from 4 GB to 8 GB per episode. For a full season, this would consume significant hard drive space and require immense internet bandwidth to stream or download. It's not a formal standard but a widely