Originally Posted by Bors Mistral
Originally Posted by aridneptune
...My sense is that if one doesn't care about the software-enabled 'motion smoothing' it doesn't matter. Films are native 24fps anyway...
I don't care about software 'motion smoothing' at all, but an actual 120Hz panel is important. To give an example with the 24fps film content that you mention:
60/24 = 2.5
120/24 = 5
In the first case you have to use 2:3 pulldown for your movies, while on a real 120Hz TV with a 24 frame movie mode your 'film' content will do considerably better.
I want to correct my earlier post.
From the L7400U Users Guide (found by DanDiego): http://support.toshiba.com/support/staticContentDetail?contentId=4005194&isFromTOCLink=false
Page 101: "ClearScan™ 240Hz uses both frame interpolation technology and advanced backlight control with image synchronization to quadruple the TV refresh rate for an even clearer fast motion video."
I assumed (as did others reading this) that "quadruple the TV refesh rate" means that the native panel refresh rate is 60Hz, but thinking it over more carefully, this cannot be correct and this in not the correct reading.
Frame interpolation only has value for a panel that has a 120Hz native refresh rate. Incoming OTA video is at 60fps and frame interpolation can be used to create intermediate frames to have a resulting video stream at 120fps but this can only be used if the underlying is capable of accepting and displaying video at 120fps. So the L7400U must have a 120Hz native panel.
In addition, a 2-segment scanning backlight is used to reduce the pixel 'ON' time by 50%, resulting in an effective refresh rate of 240Hz.
The reference to 'quadruple the TV refresh rate' be in reference to the incoming 60Hz video signal, not the native panel refresh.
So use nothing and refresh is at 60fps with full pixel ON time of 16.7ms and motion blur is as bad as it can be at 100% brightness.
- Use only motion interpolation and refresh rate in increased from 60fps to 120fps with pixel ON time of 8.4ms and motion blur is reduced by 50% (120Hz effective refresh rate) at 100% brightness.
- Use only backlight scanning and effective refresh rate remains at 60fps but pixel ON time is reduced to 8.4ms and motion blur is reduced by 50% (120Hz effective refresh rate) at 50% brightness.
- Use frame interpolation AND scanning backlight and refresh rate is increased to 120fps and pixel ON time reduces to 4.2ms so motion blur is reduced to 25% (250Hz effective refresh rate) at 50% brightness.
The LCD panel of the L7400U almost certainly has an LCD panel with a native refresh rate of 120Hz, not 60Hz.