Hello Adrian,

#208544
Avatarneilrued
Participant

Hello Adrian,

 

Please accept my apologies for the delayed reply, I've been busy finalizing assessment tasks for a course I have completed.

 

I hesitate to recommend a particular TV model or brand because different manufacturers apply color decoding and image rendering differently. Whilst for regular programming and Blu Ray play back these differences are not noticeable, when taking a look at demanding applications with high frame rates, these differences may become more bothersome for some folks.

 

The reason is that not everybody's eyes respond to color in the same way. Some people are more sensitive to the red and infra-red region of the spectrum, and others are more sensitive to the blue and ultraviolet regions. I'm in a rare minority where I'm sensitive to a wide spectral range. For instance I can see Near Infra Red light at 780nm, as faint red glow, and I can see a bluish haze during sunset in summer. Other people can't see what I see, they see one or the other.

 

When comparing TV sets in a store, what doesn't help is that retailers employ the old trick of adjusting the settings on particular models so the brightness, contrast and color look their best, and on other brands or models, they adjust these to look at their worst. This helps them sell more of a particular brand or model they want to sell most of. Sometimes some retailers will push a particular brand or model, if they don't have the particular short list of brands or models you ask for. They even try to tell you that they are all the same because this or that brand all use the same LCD panels. There are actually two countries I know of that make LCD panels; China and South Korea. Also there's no way to know for sure which models use Chinese or South Korean panels.

 

The origin of the panel doesn't matter because brands such as Panasonic or Sony, have very good quality controls and they buy the best panels from Chinese and South Korean manufacturers. The other parameters influencing quality are the electronics and the firmware used to generate the images.

 

For highest possible performance, I'd list all models with the fastest response panels, bearing in mind the rough general principle the faster the LCD's response time, the higher the price of the TV. The fastest LCD panels are 5ms, and the generally cheaper TVs use 8ms panels.

 

Another aspect to consider, is the maximum progressive frame rate a TV's electronics can deliver. Here is where careful attention to a TV's technical specifications are important; first don't trust the manufacturers' published technical specifications because they omit or embellish some parameters.

 

I was disappointed that even JVC, Panasonic and Sony were not properly representing some models of High Definition video cameras; for years their previous models used Standard Definition image sensors, and they used firmware upscaling in their cameras' microcontrollers to generate an artificial HD image. This is the reason a lot of so-called HD footage published online, doesn't have the same image sharpness as what's available when viewing Blu Ray movies shot on a true 1920 x 1080p resolution image sensor camera, and viewed on a true HD (1920×1080) panel.

 

Later generations of HD camcorders used 1280 x 720p or 1440 x 1080p image sensors and used upscaling technologies.

 

The first camcorders I have seen that uses a native 1920 x 1080p image sensor, are the new JVC Everio GZ-EX505/515/555.

 

Blu Ray movies are sometimes shot using true 1920 x 1080p image sensor cameras, or shot with 3840 x 2160p image sensor cameras and scaled down to 1920 x 1080p for current generation Blu Ray players.

 

After the 1080 and 2160 vertical image sensor resolutions, I put the letter 'p', to designate 'progressive' instead of 'i' for inter-laced.

 

60Hz does not automatically mean 60p, here's why: When the first analog TV systems were developed, the designers initially did not allow for the way the human visual system perceived the electron scanning used to build up an image on the screen. Consequently people saw visual artefacts such as flickering and jerky motion of fast moving objects.  To work with the way the human visual system functions, the analog TV researchers devised techniques such as a blanking interval between each frame, and inter-laced scanning. To sum up, the original TV scanning used progressive scanning and would show full frames 30 times a second without blanking intervals between each frame. Unfortunately the human visual system did not react well to this, and they redesigned the scanning system to send 60 half frames per second, and introduce a blanking interval between each half frame, to fool the human visual system into seeing 30 full progressive frames per second.

 

Why do they use 60Hz?

In the USA, the alternating current (a.c.) voltage delivered to homes, used a 60Hz cycle; to minimize interference in the TV picture, they synchronized the frame rate to the a.c. mains frequency. To match the TV frame rate as close as possible to the 24 frames per second used in Hollywood films, they halved the TV full frame rate to 30 frames per second. Essentially to the 24 film frames, they electronically interleaved 6 blank frames between certain intervals of film frames, to pad the required 30 frames per second.

 

How does interlacing work?

Each NTSC image frame was made up of 480 vertical lines. In the first scan, the TV camera electronics scanned every odd numbered vertical line, and this was the odd 240 half frame, next the TV camera scanned every even numbered vertical line, producing the even 240 half frame. Each half frame was sent at the rate of 60 frames per second, with blanking intervals between each frame. The blanking intervals consisted of 22.5 additional lines with no image information, so each half frame had a total of 262.5 vertical lines. The human visual system automatically blends the two half frames and we see it as a full frame with reasonably smooth motion and free of flickering.

 

Why are frame rates these days expressed as 29.97?

In the development of Black and White TV technology, the bandwidth for the image was set at 5.5MHz, with a sound frequency set at a particular frequency separated just enough from the image bandwidth to prevent interference between the image and sound.carriers. With the introduction of color, space had to be allowed for the color sub-carrier frequency, and to prevent interference with the Black and White luminance (brightness) image and sound carriers, the NTSC TV standard was modified from 60 half frames per second to 59.94 half frames per second, or from 30 full frames per second to 29.97 full frames per second.

 

This is why video camera specifications for interlaced video settings on NTSC specify 60i as 59.94i, and 30p as 29.97p. For prosumer cameras they specify for film camera compatible frame rates, the 24p as 23.98p under 60i setting. The reason for the slight reduction in the frame rate, was to accomodate the color information, whilst maintaining backward compatibility with older Black and White TV sets.

 

High Definition TV sets, even those with 1920 x 1080p LCD panels, receive broadcast TV signals as 60i (59.94i) signals to maintain backwards compatibility with older color Standard Definition TV sets; essentially the High Definition half frame interlaced images (1920 x 540) have their resolution reduced by a Standard Definition set top box, and the same frame rates are used for display by these older TV sets.

 

I'm not certain if the situation is different when connecting a wide screen HDTV, using an HDMI connector to a Blu Ray player, or a PS4, if the information is sent using 60i or 60p or higher (60 full frames per second) frame rates.

 

Another feature TV manufacturers promote is the 100Hz or 200Hz smooth motion technology their TV sets can display, for smoother motion. On some Internet forums, some people have found the 100Hz smooth motion feature annoying to their eyes and prefer to leave it switched off, other folks don't mind this feature.

 

The best decider are your own eyes. I'd suggest going online and researching as many online Internet forums as you can, where different PS4 owners discuss their experiences with their TV sets. From that, I'd generate a short list of TV brands and models, and visit as many different stores as you can to view the image quality and response to fast moving images, and judge which screens look the best to your eyesight, and further reduce your short list.

 

Next I'd research online to find out how many HDMI ports (the more the better) each model has; if you can get a model with four HDMI ports, then you'd be doing well: one port for your Blu Ray player, one port for your PS4, one port for a laptop, and one port for a HD camera.

 

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