This was an answer to a question in another post which a ?moderator was asking for, but it was moved here.
To answer your question, the Zoom setting is inappropriate primarily on devices wider than 16:9 dimension (most phones) in at least these situations:
- 4:3 content
- 16:9 content
Letterbox 4:3 content (correct display)
Zoom 4:3 content (cropped video)
Letterbox of re-endcoded 16:9 content without upper/lower bars (correct display)
Zoom of re-endcoded 16:9 content without upper/lower bars(cropped video)
All of this compared to a direct rip of a Blu-Ray disc using MakeMKV.
Letterbox of direct 1:1 Blu-Ray rip with hardcoded upper/lower bars (now incorrect display, compared to the above examples)
Zoom direct 1:1 Blu-Ray rip with hardcoded upper/lower bars (now correct display, the opposite of the above examples)
Reencoding all that 16:9 content would “fix” the issue when using Plex on a phone and allow me to just use the letterbox setting but that is not a good choice. My main serious media watching is using madVR and an HTPC on our main media TV as this simply provides better quality than any other option on a 77" screen sitting 7 feet away. Plex works fine on a 16:9 TV so the only time this is a problem is with a phone. It doesn’t make sense to either have 2 copies of every Blu-Ray rip or to sacrifice the quality of all the Blu-Ray rips just to make the phone app work correctly. I’d rather just have to toggle between Zoom and Letterbox as needed depending on the content, but it is not ideal.
Addendum - as I mentioned/suggested in my thread that was linked above, in my mind, if it were possible, Plex would remove black bars from top and bottom while transcoding only. Handbrake can do this. Now maybe that doesn’t mean Plex can do it, but it was an open suggestion. The bars are the problem. That way, primarily with phones that can have wacky dimensions, the video will fit the screen (while remaining in Letterbox setting) as fully as possible without cropping video.
Addendum 2 - I may be a misunderstanding, but it seems to be that it was thought that the zoom setting of the Plex app was affecting other parts of my phone. This was not the case.
