Originally Posted by spyboy
The XBR 8 is a 120 Hz panel with a scanning back-light.
The best of the 2009 sets are true 240 Hz which doesn't include a scanning back-light.
True for Sony sets (if you count the XBR8 as a 2008 set, even if it was a catalogue set in 2009).
Examples include the Samsung LNB750, the Sony XBR 9, and the Sony Z5100.
Yes, examples. Aren't you forgetting the Samsung B8500 as one of the best sets of 2009?
As time goes bye features trickle down to less expensive sets.
120 Hz sets without scanning back light should start to get scanning backlight as features trickle down.
If they are LED-based and offer some type of local dimming then this will inevitably be the case as it is pretty simple to implement as an extra function. Pure edge-lit LED sets will offer backlight blinking which isn't as good but better than nothing.
I don't see scanning back-light as the best implementation of motion blur reduction.
I'd like to have both - and the choice to use what I deem best for the type of material (video) I have at my hands.
I would rather see true 240 hz refresh rates like the LNB750 etc. The true 240 sets "insert 3 entirely new frames for each original frame". That's how Samsung explains AutoMotion Plus 240Hz.
I hate to keep repeating this, but this is the hierarchy of motion blur reduction:
1) True 240
2) 120 Hz with scanning back-light
3) 120 Hz
40 60 Hz
Well, you may hate repeating this but I think that some form of backlight scanning or at least blinking (higher brightness sacrifice) is preferable for movies (24p material).
Here are some reasons without even taking the other feature of local dimming sets into account:
- Backlight scanning is cheap - if you already have local dimming on the set. For 240 Hz interpolation you need twice the interpolation hardware because of timing constraints (with the 2009 sets). In the future the point is moot as the chipsets will be higher integrated.
- Twice the interpolation means twice the amount of artifacts - and none of the mentioned sets above is artifact-free.
- Interpolation always bears the risk of the dreaded soap opera effect - all of the above sets are known for that. Many experts recommend disabling interpolation and only use 60 Hz mode (with 24p processing) instead. The reason is that interpolation may - depending on the scene - only affect moving objects on a static background. Backlight scanning on the other hand affects the whole picture and changes the hold-type nature of LCDs to a more impulse-like display like plasmas and CRTs. They preserve the typical 24p judder much better than sets that interpolate like crazy.
- Backlight scanning can be timed to happen while the liquid crystals are moved, which introduces a slight amount of blur. Therefore this is a good method to mask this blur. Interpolation not only can't mask this blur but also increases it! A 60 Hz video with three interpolations could result in four times the amount of crystal movement, hence increased blur.
Backlight scanning increases motion sharpness (even a plasma-friendly reviewer like David Katzmaier tested the XBR8 for about 1000 lines of motion resolution) so it makes movements sharper, but it doesn't make them exaggeratedly smooth.
For some materials a highly smooth video-like look isn't a problem (sports or nature documentations for example) but for many people it effectively kills the traditional movie look.
The best solution would of course be: Having both! A 240 Hz set with *optional* backlight scanning - and this is also inevitable for a certain price range of sets...