Synnöve said:

I don't understand the desire for a blu-ray level 50gb file; you most likely won't be able to notice the difference! Most films on a BD50 only take up 25 to 35 GB on the disc after special features and aux audio tracks...

If you're going to spend the time and resources to create that big of a file, why not make actual use of the extra space and create something that exceeds blu-ray (circa 2008)? Hell, create a 264 encode with 2K resolution that uses P3 color space @ 4:2:2, 10 bit, and you have a file that'd be worth downloading due to it looking better than any Blu-Ray.

Depends a lot on the grain and weave.

A grainy and weavey film doesn't compress very well at all with even the most modern codecs, so even with a 50GB file you can struggle sometimes.

If you are happy to stabilise the film and reduce the grain significantly, then it compresses better and a BD25 can look pretty close to the stabilised, reduced grain source.

It all depends on the source material and how close you want to stick to it.