Assuming a backup rip from a brand new 3D blu-ray movie, using lossless codecs would mean that the most important questions at hand would be: Which lossless codec is widely used and compatible?
Since the original Blu-ray movie in .m2ts format and the best way to get 1:1 copy of original BD movie is to copy the entire disc into .m2ts format, but in this way you would also get exactly same file size as original one, at least 20GB, this way takes too much hard disk space. If you want to Backup Blu-ray or 3D Blu-ray in 1:1 copy, click the link to figure out.
According to my own experience, I prefer backing up BD/DVD disc to mkv format using ByteCopy because it not only copies movie to mkv without quality loss, the conversion process is within 20 minutes, very efficient. Moreover, the Best Blu-ray ripping program will will help us retaining Multi-subtitle and multi-audio tracks. Below is a guide for you.