Question on Dual Layer Burning and file size

[milkdog]

When I attempt to burn an ISO file (3.93 G) to a dual layer DVD using , I get a pop up that says:

"media inserted in Drive E is double layer, but the output only needs single layer media"

I am assuming that it only needs one layer because the file size is not big enough to need dual layer.

My question is, why is an ISO file so much smaller that when you rip to the folder that has the video_TS and audio_TS. Example, Harry Potter Goblet of Fire...ISO file is 4.19 GB, Video_TS folder is 7.12 GB

I burn my ISO files at DVD9. Am I losing quality by going to ISO file? And is quality better on dual layer disk even though is is not required?

Thanks in advance for the advice.

[AGJ]

Not sure why you getting the different file size as they should be the same size. Are you doing main movie or Full DVD? Maybe you selected main movie for the ISO and Full DVD for the VIDEO TS which would suggest the larger file

[maineman]

Aside from operator error, this doesn't make any sense.
Are you getting this message on multiple discs?

An .ISO is simply a container.
It is comprised of the same .vob, .bup and .ifo files found in a VIDEO_TS Folder.
These files when ripped, are compressed or not.
If they're not compressed, then the actual files are identical in size.
While there can be slight variation in size with respect to containers and the manipulation of files, these variations are insignificant.

Take a look at some of the .vob files themselves and compare sizes.