Are 50GB dual layer BDR and BDRE smaller than pressed Blu-Ray retail discs? (1 Viewer)

i'm making backups of my purchased blu-rays that I own in fear of it being destroyed in a fire or scratches.
I have discovered that # of Blu-Ray movies actually have more sectors/data than a blank BDR or BDRE, how is that possible? Back in the DVD5 or DVD9 days... it was the same across the board. a DVD9 could have been burned to DVD9 Dual Layer no problem.
Touch of Evil UK import for instance has 1GB over the limit. 47GB vs. 46GB that BDR and BDREs allow... this is strange... I just thought *ALL* BDs were supposed to adhere to the same standard just like DVD9 rips can always be burned on DVD9 Dual Layers. I never had to overburn on those no matter how much the original DVD9 was, I always found a way to fit it. BD25 that are over can fit on BD50 if needed but anything over BD50 I have no idea... what do you do on these?
if I overburn it would error out and the BDRs would be a coaster. if I truncate I get playback errors and burned copy won't verified properly against original ISO or BDMV folder.

Yes and no. 50gb is actually slight less because it's measured in 1000mb per gig instead of 1024, but in a home burned disc it also has to write an open TOC which costs you some.

so for bd that is full it is impossible to duplicate 1 to 1?

The simplest solution is to strip out an extra m2ts for a preview or something from the ISO. Surely the previews aren't that important

yes but there is no previews in this. do i just manually delete the m2t i dont need?

Yes. You are generally best off opening the stream file in MPC-HC, then if it's a preview or something worthless, just delete it.

hmmm i will test this out wont this cause playback issues later on?

Nope. Worst case, the BD-J skips missing streams . I usually use AnyDVD and strip out all the previews. It's got an automatic option for that.

didnt work i removed about a 1gb of bonus content i didnt need

I'll link a guide to you.

Try ClownBD as it can strip out previews for you automatically. Otherwise follow a guide from videohelp or doom9.

it worked dave! not with clownbd but i reripped it w/o any auto deleting of short segments then j just manually deleted the 1gb bonus stuff and the disc plays! when you try to play the missing content it just clicks back into the menu lolz