Question Refresh rates on LG 43UH661V & Panasonic 40DX700B

johnnynuffin

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Hello all

Looking to get a new TV with an 40-43 inch screen and have narrowed it down to these two models. I will use the TV for watching sport and occasional PS4 gaming session, so the refresh rate is important.

Before going to view them in a shop, does anyone know what the real refresh rates are?

After going to both manufacturers sites they have listed:

LG - 1200 PMI
Panasonic - 1400 Hz BMR

Thanks,
JN
 
interestingly the LG has native refresh rate of 60 Hz (acc to this): 42.5" LG 43UH661V - Specifications

and the 2015 3D model 652V had refresh rate of 120 Hz...however "PMI" of the 2016 (661V) model is 1200, v 900 for the older model with higher refresh rate...anyone able to explain this?? Is it due to a much higher strobe rate of the backlights??....
 
Don't be fooled by the hz manufactures quote, its not the actual refresh rate of the display. Also don't assume just because a TV has higher hz that it will be good for gaming. There is more to gaming on TVs than hz.

Most tv's can't accept a signal past 60hz, 4k or 2k, so the only reason they have higher hz is so they can reduce blur during fast scenes or games. Some tv's do this better than others. Some 60hz are even better than higher hz tvs.

Having said that, I think the best gaming/sports tv would be either last years Sony x8c series from last year or the Samsung 6 series either from this year or last.

Panasonic tvs tend not to be best for gaming due to having more input lag and motion blur and LG's overall tend not to get good reviews, they tend to be average to poor all around.
 
Hi Dodge, I'm going by the actual specifications on an independent website re the panel refresh rates: the 2015 LG one is def a 120 Hz (vertical refresh) panel v 60 for this year's 661V model. See 42" LG 42LF652V - Specifications

But the MPI as mentioned is higher on the 60 Hz panel. Guess this is due to the updated motionflow software. Also the 2015 model (LF652V) does seem to get a lot of really satisfied customer reviews, many saying how clear the display is:
Buy LG 42LF652V 42 Inch Full HD Freeview HD 3D Smart TV at Argos.co.uk - Your Online Shop for Televisions.

It is a 3D tv so maybe has a better "build quality"... Seriously tempted!!
 
I would just ignore motion control, at most you may want to use it for sport at its minimum setting, there's no need to have higher modes than just the very minimum.

Also remember that panel Hz doesn't always translate into better motion. One of the best TVs for motion blur at budget prices is the Samsung JU6400 and that's a 60hz panel.
 
Picture processing, response time. If you look at OLED or plasma TVs they have next to no response time which makes motion naturally a lot smoother.

LCDs will always display motion worse because the technology exhibits more if a delay between the signal being displayed and received. (Eg the time it takes for the backlight to adjust compared to just a led).

You want to be looking for a TV with as little motion blur as possible and forget about motion interpolation. All that feature does is insert frames to give the appearance things are smoother, or inserts black frames making it seem smoother but also darker.

For normal viewing you want to leave motion interpolation off usually, some people use it for faced paced sports but by having it on, you usually introduce either a darker picture or artifacts.

For normal viewing including gaming you want a TV that handles motion well without interpolation.

See

Motion Blur of TVs

Judder-free 24p on TVs

Motion Interpolation on TVs: Soap Opera Effect
 
Picture processing, response time. If you look at OLED or plasma TVs they have next to no response time which makes motion naturally a lot smoother.
Doesn't less blur make motion appear less smooth? eg a film/film sequence with a very short shutter open time is going to look more 'choppy' (less smooth motion) than one with a longer shutter open time (more motion blur)?
LCDs will always display motion worse because the technology exhibits more if a delay between the signal being displayed and received. (Eg the time it takes for the backlight to adjust compared to just a led).
What do you mean buy "compared to just a led"? Do you mean compared to OLED?

With an LCD TV (with LED backlight) that has it's local dimming (or similar tech) disabled, isn't it going to just keep the same backlight level on throughout (no time needed for it to adjust)? So then you've only got the liquid crystal response time (and picture/audio processing delay).

I also thought I read a review that I think said the Panasonic 902b, with it's 512 dimming zones took a certain amount of time to adjust its zones, eg. during credits (though I can't find that review now. I thought it was the hdtvtest one but it doesn't say that currently) but that it gave a "plasma" look to it. Though I don't see why more dimming zones really has to take (noticeably) more time to adjust than less. Surely they can be told to adjust almost instantly - especially if wired in parallel?

Surely OLED and LCD are the ones that really can potentially have naturally smoother motion than plasma, due to Plasma generally maxing out at 60Hz. Though most current film content will be 24p and without interpolation won't really get smoother motion (ignoring the blur produced by the panel/in the source due to shutter) - though true full UHD res 100/120Hz TVs might be out in 2017 (or maybe a year or 2 later?)? Also if a particular Plasma always output at 60Hz (not a 24Hz multiple - I think some did eg. 48Hz though) surely the LCD/OLEDs that have a higher refresh rate will output without (or with less of) the pull-down judder of 24->60Hz.
 
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Doesn't less blur make motion appear less smooth? eg a film/film sequence with a very short shutter open time is going to look more 'choppy' (less smooth motion) than one with a longer shutter open time (more motion blur)?

Less blur does, but the key is understanding what causes the blur. There is a set amount of time (a limitation) that an LCD takes to display an image. It doesn't matter how fast the panel of the tv draws in a second (hz) the TV will always be limited by how long it takes to even display the image in the first place.

What do you mean buy "compared to just a led"? Do you mean compared to OLED?

The difference in technology, an LED or OLED is going to be able to light and change a lot faster than an LCD with a backlight. You need to wait for the backlight to respond, this process takes a lot longer than just lighting up some phospor or an OLED, thats why motion is so much better on CRT/Plasma/OLED compared to LCD and why a lot of people just can't go back to LCD tv's after having a Plasma for example.

With an LCD TV (with LED backlight) that has it's local dimming (or similar tech) disabled, isn't it going to just keep the same backlight level on throughout (no time needed for it to adjust)? So then you've only got the liquid crystal response time (and picture/audio processing delay).

By no means am I technical enough to understand the details, but you can imagine when you have LED's behind a screen rather than an individual LED (OLED) or Phospor (Plasma/CRT) it is going to take some time to even work out how bright it has to be. The back light may be at a constant level, but how does it define to light up a particular area of the screen when the ratio of LED vs LCD pixels are so low. Does it show the whole picture at full brightness because just one part of the picture is bright when another is low? This decisions, processing etc takes time. On an OLED its on a per pixel basis, so the whole process happens a hell of a lot faster.

This link explains everything a lot better than I do: Motion Blur of TVs

Surely OLED and LCD are the ones that really can potentially have naturally smoother motion than plasma, due to Plasma generally maxing out at 60Hz. Though most current film content will be 24p and without interpolation won't really get smoother motion (ignoring the blur produced by the panel/in the source due to shutter) - though true full UHD res 100/120Hz TVs might be out in 2017 (or maybe a year or 2 later?)? Also if a particular Plasma always output at 60Hz (not a 24Hz multiple - I think some did eg. 48Hz though) surely the LCD/OLEDs that have a higher refresh rate will output without (or with less of) the pull-down judder of 24->60Hz.

Judder and motion blur are two different things. LCDs and plasmas, even ones with native 60hz refresh rates can display 24hz without judder. Its only older models that struggled and had to perform pulldown to match the 60hz refresh rate.

I don't know if any of what I said makes sense, but I just know that a lot of people don't seem to understand the differences, they look for faster HZ tv's thinking they will exhibit less blur, yes they may have less blur than the same tv with a slower refresh rate, but this doesn't mean there isn't a 60hz or 50hz tv out there with a faster response time that does a better job. If we could feed the tv's with the same signal of the panels this would change, but sadly we can't. I hope the new consoles can and in the future HDMI specs will come in to accept 120hz+.
 
The difference in technology, an LED or OLED is going to be able to light and change a lot faster than an LCD with a backlight. You need to wait for the backlight to respond, this process takes a lot longer than just lighting up some phospor or an OLED, thats why motion is so much better on CRT/Plasma/OLED compared to LCD and why a lot of people just can't go back to LCD tv's after having a Plasma for example.
But there are no "LED" TVs. The LED TVs are LCDs with an LED backlight.
By no means am I technical enough to understand the details, but you can imagine when you have LED's behind a screen rather than an individual LED (OLED) or Phospor (Plasma/CRT) it is going to take some time to even work out how bright it has to be
I don't really see why. If on my (1080p) TV I have "Smart LED" turned off (which I don't usually), it doesn't need to work out how bright the LEDs behind have to be (depending on the picture content) as the LEDs behind should always be lit to the same value (approx same output voltage?).

eg. with a direct lit fulll array local dimming TV:
if Smart_LED=On then adjust led zones according to picture content and backlight value
else keep all leds at the same output level regardless of picture content (ie. base it just on the user specified "backlight" parameter from the picture settings).

Also, I'd have expected (not positive though) the LCD TVs liquid crystals to take longer to change than adjustments to the backlight (in theory and if done right - I may be wrong though).

Also, lets assume it has "Smart LED" (or similar) turned on, and it does need to take a bit of time to work out how bright to light the LEDs. Surely that actual processing (done on some sort of CPU or more probably GPU?) will be incredibly fast and the processing on the (say GPU) will have no visible effect on the picture other than possibly the slight delay (basically the CPU/GPU processing should be able to be done in <= the same time an OLED TV takes to decide what light level to output for all the pixels on the screen. The CPU/GPU processing will need to (and will) take less than the refresh rate of the LCD screen. It will be things like interpolation that will lead longer delays, since they need more frames to work on (I don't really see why the algorithm for determining the LED backlight value for one frame, if done right, would really need to be based on more than one source frame).
Judder and motion blur are two different things. LCDs and plasmas, even ones with native 60hz refresh rates can display 24hz without judder
Exactly how would LCDs that could only output 60Hz (ie. not output any other refresh rate) output 24p content without pull-down judder, since 24 into 60 doesn't go without a fraction (so surely they must be displaying some output frames of the 24 fps source for longer than others - and therefore giving pull-down judder)? I'm assuming a constant backlight and output of original frames as is (no blending etc.).
 
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I don't know the technicality behind why it is that LCDs have longer response times but they do, the tech goes through more steps before it has to display the image compared to others and thats why LCD's always have higher response times. The liquid crystal cells don't have the ability to dim or brighten themselves, at some point there is a filter or a blind or something that opens and closes to let more or less light through, I'm sure that alone takes time. Thats on top of the time it takes to "think" about it. Yes they have fast processing, but it all adds up. Unlike OLED and plasma where you just have to light up an individual pixel or phospor or whatever, there isn't 1 LED for every LCD pixel on an LCD display, having an LED backlight improves on the old strip lights but they still aren't going to be able to light each pixel individually, for this you would need a tiny LED for every pixel. If you could light up each pixel more accurately there wouldn't be the need for tv's to have dimming zones and LCD's wouldn't have any blooming when displaying light images or dark backgrounds.

Tv's that are not multiples of 24hz can either interpolate frames to 60hz or adjust their display hz to display 24fps content. Those tv's that just interpolate introduce tecline judder, but those tv's that don't actually reduce the panels refresh rate to 24 or 48 or whatever to display 24p smooth. This is how it was possible even before 120hz panels to get smooth 24p. Having the refresh rate at 120hz just makes the whole process easier, it doesn't mean its not possible with a native 50 or 60hz panel.
 

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