(August 5, 2010) Do movies shot on film look like videotape on your LCD HDTV? Does it bother you? If so, you’re not alone. That problem tops the email complaints we get from readers and it comes exclusively from those owning 120Hz or 240Hz LCD or LED LCD HDTVs. It never comes from plasma owners.
The visible reduction of film grain and other film-based irregularities that should be present in the picture is often referred to as the Soap Opera Effect (or SOE) because the increase of the frame refresh rate from the 24 Hz to the rate of the display (120 or 240Hz) appears like a videotaped soap opera. While viewers don’t see the problem when watching sports or other live or taped broadcasts (which are shot at either a 30 or 60 Hz frame rate), they are rightly troubled when movies look like video, though not everyone is bothered by it.
A number of solutions provide a fix for some but not for all LCD/LED TVs suffering from SOE Ã‚Â What follows are the SOE “whys” and the fixes currently available as well as news of a possible total solution coming to 2011 models.
HD Guru began testing HDTV motion blur in 2007 using a test disc from the Plasma Display Coalition that moves a resolution chart horizontally at a fixed rate of roughly 6.5 pixels per frame. 60 Hz LCDs have very poor motion performance, with a reduction from 1080 lines resolution per picture height (static) to around 300 lines with motion. The TV manufactures followed up with the introduction of 120 Hz LCD (and LED) flat panels and later adding 240 Hz models. The 120 Hz models raised the motion resolution to around 600 lines and the 240 Hz models kicked it to the 900 and up (depending on the model tested), however both types introduced the Soap Opera Effect when viewing 24 frame per second content which includes all film based motion pictures. To achieve 120Hz or 240Hz instead of the standard 60Hz rate requires a circuit called Motion Estimation/ Motion Compensation (ME/MC), which creates interpolated frames between the real frames. The interpolated frames have the artificial appearance that imparts the video look of a soap opera. You can turn off the interpolation on a number of displays, which will change processing to repeating the frame 5 times (in the case of 120 Hz displays) however, degradation remains visible on a many 120 and 240hz displays. According to a MC/ME chip maker this is due to the circuit altering the image even when it is not inserting interpolated frames.
Currently the only consistent method to eliminate the effect on LCD and LED HDTV is to bypass the 120Hz or 240 Hz MC/ME circuits thereby forcing an TV from utilizing frame interpolation. This is accomplished on Samsungs or Sonys (we have not had a chance to check other makes and models) by engaging the “Game picture mode. If you notice the Soap Opera Effect with film based content on your LCD or LED TV (and almost everyone does) you will see the difference in the “Game” mode. Of course motion blur and judder (jerky motion during horizontal pans) will appear without interpolation (or frame repeat), so choose the artifact you prefer. For Blu-ray movies, be sure set the output of your disc player to 1080p/60 to assure 3:2 film conversion occurs. Frame repeat is a better method, although as stated above, many sets continue to create SOE artifacts in this mode too.
Plasma HDTVs have inherently high motion resolution without the SOE. This is due to the way they create a high definition image. Plasmas create moving images by a stream of short bursts of light (at least 600 times per second) instead of a “sample and hold” technique employed in all LED and LCD HDTVs. The result, 900 lines to full 1080 lines of motion resolution (meaning no blur) while maintaining the look of film. If you want film-like image on your flat panel without motion blur, buy a plasma (Samsung D6500, D7000, D8000 series and Panasonic GT30 and VT30 series models now offer 4X frame repeat to eliminate 3:2 judder as well). Plasma HDTV pricing is at an all time low while sales are at record highs and overall performance is better than ever.
A 2011 Solution
We spoke to a representative of Integrated Device Technology (IDT) the owners of Silicon Optix HQV processing technology (obtained when they purchased the company a few years ago). IDT is introducing new MC/ME frame conversion chips. It claims their chips allow LCD and LED TV makers to use 120 Hz or 240 Hz in their respective displays without the dreaded SOE and other artifacts. They have promised us a demo in September at the CEDIA Expo and we will look and report with hopeful but as always skeptical eyes. Here’s the relevant section of IDTs recent press release.
“Integrated Device Technology, Inc. a leading provider of essential mixed signal semiconductor solutions that enrich the digital media experience, today announced the industry’s first motion-compensated frame rate conversion processors with an integrated resolution-enhancement engine for use in 120Hz and 240Hz televisions and high-definition video projectors. The new IDT VHD1200 and VHD2400 devices feature the industry-leading IDT HQV MotionSMART technology, which provides smooth motion and full-detail images while minimizing side effects seen with competitive solutions.
The new IDT frame-rate conversion processors are also 3-D capable, providing smooth motion with minimal side effects, which is significant for 3-D where varying side effects could be very distracting to the viewer.
Ã¢â‚¬Å“IDT continues to provide its customers with innovative video solutions. These new frame rate converters provide smooth motion and crisp, clear images for today’s HD and 3-D displays,”said Ji Park, vice president and general manager of the Video and Display Operation group at IDT. “The VHD1200 and VHD2400 follow in the footsteps of our other innovative video processing solutions, providing our customers devices that deliver the best picture quality.”
The IDT HQV MotionSMART technology includes per-pixel processing, providing the capability to make intelligent localized decisions in the detection and processing of complex images and motion in video images. The IDT solutions also feature cadence detection, which removes judder from sources with cadence, and a wide detection range to eliminate “flickering” when images move horizontally, vertically or diagonally on the screen.
An IDT spokesperson says their new ME/MC chips will appear in select 2011 LCD/LED flat panels and front projectors. Stay tuned.
Samsung recently offered a new firmware update they claim shuts off its the ME/MC circuit when its Auto Motion Plus feature is set to the “Off” position. An alternative (according to a Samsung spokesperson) is to set a Samsung 120 or 240 Hz LCD or LED TV to “Clear” mode or to move the “Judder” control to “0″ using the “Custom” mode (post firmware update). You can update your Samsung LCD or LED TV by connecting it to your Internet router. For more on firmware updates read this hdguru.com/hdtv-owners-need-to-be-aware-of-firmware-updates/1964/
Have a question for the HD Guru?
Copyright © 2010. All rights reserved. HD GURU is a registered trademark.