Unless you like frame rate conversion artefacts 24 frame film i.e. 23.976Hz film on Blu-ray output at 50hz would be far from ideal. The reason 24 frame film works at 60Hz output is due to 2:3 pull down albeit with motion stutter but this doesn't apply to 50hz output.
I certainly wouldn't consider 50hz an alternative "sweet spot" for 24p Blu-ray film by any stretch because it isn't.
If you have grown up in country watching film using NTSC @ 59.94Hz it's very likely you're conditioned to 2:3 pulldown and don't notice it or don't notice it as much. I grew up watching film on PAL and later watching film on NTSC using 2:3 pulldown and the latter appears to stutter/judder to me. No big brother just different choices made in those countries regarding broadcast standards. Blu-ray provides a common feature film option i.e. 24/23.976 that avoids NTSC or PAL specific timing versions of the main feature as with DVD.
Is it certain that "auto" always means 60Hz? (If so why are there three options 60/50/Auto when two would do?) My Tv (a Sony) is a multi-standard model having auto input selection so it can play both NTSC and PAL. So I am wondering if the player output and the Tv are both saying to each other "I can do everything" then which format are they finally going to agree on? Is it even a deterministic choice, or may they sometimes agree on 50Hz and sometimes agree on 60Hz?
If you're referring to 24p Blu-ray film then "multi" TV system means "60Hz" if 24p is disabled. There are multiple options because some displays may not support 60hz or 50Hz (uncommon in Europe) and in this situation frame rate conversion may allow an image albeit less than optimum. The source frame rate should determine output and other FRC options should only be considered if the optimum rate isn't supported.
It's pretty simple -
"TV System: Allows you to choose the output video system or broadcast standard (PAL/NTSC) to
match the type of TV.
NTSC (default US model) – When playing NTSC-encoded discs, no system conversion is performed.
PAL-encoded content is converted to NTSC output. Blu-ray Discs encoded at a 24Hz frame
rate are converted to a 60Hz frame rate if neither 1080p24 Output nor Source Direct output
resolution is enabled.
PAL (default European Model)* - When playing PAL-encoded discs, no system conversion is performed. NTSC encoded
content is converted to PAL output. Blu-ray Discs encoded with a 24Hz frame rate
are converted to a 50Hz frame rate if neither 1080p24 Output nor Source Direct output
resolution is enabled.
Multi-system – No system conversion is performed. The output video system is the same as
that encoded on the disc. Blu-ray Discs encoded with a 24Hz frame rate are converted to a
60Hz frame rate if neither the 1080p24 Output nor Source DirectIf the source is 60/59.94Hz and the TV setting is auto the output is 60/59.94Hz"
* In Europe the default PAL TV System setting has been the cause of complaints about image quality when using 24p Blu-ray film due FRC artefacts if the 24p setting isn't on/auto.
Edited by dazzerxxx - 4/10/13 at 11:49am