TV SOE Soap Opera Effect

by Ronald J. Plachno

TV "SOE" - "Soap Opera Effect" a New Oddity

if you get a new TV, particularly a late model LED type or even perhaps a PLASMA, you might notice something some people are calling "SOE" = Soap Opera Effect. What it is - is that on late model TV's the designers put something that some people call "motion smoothing" which is a very high screen refresh rate at 240 Hz or so. This was first used on LED TVs of modern days, but I hear it is also creeping into newer plasma sets. What our eyes see and brains interpret is that movies may no longer look like movies, but now may look like videotaped news or videotaped soap operas - hence SOE for Soap Opera Effect.

There are plenty of articles if you Google TV and Soap Opera Effect, but I found some of their reasoning questionable. Some do tell you ways you might be able to shut it off - the motion smoothing if you wish, and that much might be helpful to some. But I think where we should start understanding it is not with opinion, but about what did really change. And what did really change for the first time - is the speed of the movie film - the effective number of frames per second.

To follow what has changed, let us first start with history to see where we were. Movies and movie film are called motion pictures, but in truth, the pictures are not moving. What is happening is that our eyes retain an image for just a small portion of time, and that if we see many still normal images quickly in a row, it looks to us like motion. And hence it is an optical illusion of motion based on our eyes retaining images. For those of you who have seen movie film itself on a reel you can see that that is what it really is - a great number of still images next to each other on a long reel. The first movie standard for film movies was 24 frames per second - or 24 still photographs per second. Then as we play it back rapidly our eyes will believe they see motion.

Television in the US began somewhat similarly, only at 30 frames per second for the first normal type TV imaging. Television used the US alternating current that changes at 60 Hz, 60 cycles a second, to tell it when to change the images on the screen. And so the TV screen was being updated every 1/60th of a second. However, the first TV signals were interlaced. That means that each 1/60th of a second the screen was only half updated skipping every other line. On the next 1/60th of a second, the next image was interlaced between those lines. Hence it took two periods of 1/60th of a second to update the screen and therefore it was 60/2 = 30 frames per second. And for the longest time, TV was 30 frames per second in the US and film was 24 frames per second. This first TV method was called "480i" - meaning 480 lines were going down the screen and the "i" stood for interlacing meaning only half the screen updated each update time.

But then TV began to become high definition. The very first stage was something called "progressive scan". What progressive scan did was to update the full 480 lines of your tv set every 1/60th of a second meaning no interlacing, but everything updated, all lines updated, every 1/60th of a second. And so progressive scan now gave 60 frames a second. Now this was important to some of us since we noted that human beings saw this progressive scan, 480p (where the p = "progressive"), as being much higher quality than the interlaced 480i version. And so we learn that our eyes can handle changes higher than 30 frames a second - in fact can see 60 frames a second and call that higher quality.

At about this same time other high definition standards were coming into US TV. One new standard put 1080 lines down the screen but also used interlacing meaning 30 frames per second for a full update. That is the so called normal high definition and called 1080i. Now our eyes again saw improvement. For some of us mere humans, progressive scan of 480p and 1080i both looked like improvements and not everyone could tell the difference. Some high end stereo/video stores began calling progressive scan high definition, even though of course 480p and 1080i are different in both the number of lines down the screen and the difference between 60 frames per second (progressive scan) and "i" interlaced at 30 frames per second. High definition added other types such as 720p and 1080p. And so for this period there was a wide range of TV standards in the US - 480i, 480p, 720p, 1080i and 1080p. But in all new cases beyond 480i, our eyes were seeing an improvement in TV picture quality.

How was film movies seen on TV effected during these days? Only partially. Progressive scan updated the TV set more often making it clearer. However, it did not speed up movies many of which were still only 24 frames per second. This might seem odd to you, no? TV screens are now updating at 30 or 60 frames a second but movies on TV are still at 24 frames? But the truth is that unless you change the film data somehow, the slowest change is what you will see. I do believe that movies were converted from film most simply just by videotaping them. Well, the problem there is that even if the video tape is moving quickly, the original film it is now videotaping is still just the same 24 frames per second. If this makes no sense consider videotaping a still image of a potted plant. If the videotape is moving at 60 frames per second, how fast is the plant going? The plant is standing still at something far slower than 1 frame per second. So unless the original item photographed is changing more often, or unless we change the movie film data, movie film stayed at 24 frames per second as we watched it on our US TVs - even in the world of high definition.

Then things did change for film movies.

The newer LED TVs and perhaps even some of the newer PLASMA models use something called "motion smoothing" and may refresh your TV screen at 120 Hz or 240 Hz or other higher frequency than in the past. But now what they also do is to "change the data" - something not even high definition did. Now the newer systems for "motion smoothing" interpolate what the scenes should look like in between the frames. How do they do that? I did not write the software. But let us guess that if a baseball is moving rapidly across a film screen and on one frame it is far on the left and on the next frame far on the right, then a good guess might be that on a frame in the middle that does not exist now then the ball would be mid screen. But that is just a guess since as I say, I did not do that software. But now something is different for movie films. Instead of 24 frames per second, we might think the image is changing 120 frames per second or even 240 frames per second with software figuring out what the new frames would look like. In addition to this, whoever did the software might also clean up the film image removing some stray bits that do not seem like they belong when the interpolation is done. But again, only the software engineer doing the coding would know that. However, one thing that we do know, is that now the film will seem to have more frames than 24 frames per second, and this is a real difference.

And so, what does this all mean? Well, now we may know what our eyes see and we guess what our brains might make of it. But since the movie frame was 24 frames per second and we know now that our eyes can see faster movement at least at 60 frames per second, perhaps the earlier TVs - even with high definition - might have seen what we thought as a flicker on the movie screen. Also if there is cleanup perhaps movie films had a flicker and also some graininess that are gone now. And as the speed and quality goes up, the movie film on our TV no longer looks like movie film, but something faster moving, like videotape perhaps from a news broadcast or a soap opera. And hence, some call this effect "SOE" or Soap Opera Effect".

What is next? More of the same. Some TV sets in the US are now trying an experimental 4000 lines going down the screen. That is much more quality than the original 480 lines down the screen or even high definition 1080 lines down a screen. I saw a sample of a TV set doing that. It showed a city scene where one could make out every window in the city. It was almost frightening.

But as quality improves, our eyes will continue to see changes. What to do about Soap Opera Effect SOE? If it bothers you, Google TV SOE Soap Opera Effect and some may tell you how to shut it off. As for me, I intend to live with it. Whether it is higher speed film we are seeing or higher speed film plus noise reduction, it is a clearer picture than before. So "different" is not always bad. But of course, beauty is in the eye of the beholder, and you may decide to look for articles that tell how to shut it off. If you cannot find articles and do wish to shut it off, it might be under your TV menu settings and called motion smoothing or 240 Hz updates or something like that. Good luck whichever you decide.

Ronald J. Plachno

December 4, 2013