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Explanation TV terms

Explanation TV terms: This article is an attempt to Explanation TV terms that often used in real life and on this site.

This article is an attempt to Explanation TV terms that often used in real life and on this site.

Explanation TV terms- Hertz

The term Hertz (Hz) indicates how often the image on the screen is refreshed per second. In other words; every second 50 (50Hz), 100 (100Hz) or more images pass, depending on the number of Hz. Because all the content we watch on TV is 60Hz or 50Hz, and for movies 24Hz, your TV has to come up with frames when the number of Hertz of the TV is higher than 50Hz, 60Hz or 24Hz of the content. Coming up with the frames is not necessarily bad; a higher number of Hz would render the image much smoother and remove ‘motion blur’. However, there are also sounds that higher refresh rates can create artifacts (Rare shapes in the image where the edges of objects are mainly distorted) by adding extra frames.

It is often thought that the more Hz, the better the image, but this is often questioned. Researches and experiences show that TVs with 240Hz or more are sometimes even experienced as annoying and TVs with 60Hz are often very nice to watch. It’s personal, but it’s definitely not always an advantage or a reason to go for a particular TV. It is seen by many as a marketing stunt (the problem of ‘motion blur’ would no longer exist), so quickly forget the number of Hz when you see it and focus on other things.

Interlaced / Progressive

We all see the following specifications from time to time; 1080p, 720p, 1080i, etc. We know what the 1080 and 720 mean, namely the resolution of the image , but what do those ‘p’ and ‘i’ actually mean?

We have already discussed above what the number of Hz means – how often the image is refreshed per second. The content you watch on your TV is recorded with a certain number of Hz. Now there are two different techniques for refreshing the image of this content. First, there is interlacing(e.g. 1080i). This means that an image of, for example, 50Hz (standard for HD broadcasts) is refreshed 50 times per second, in two different parts: first one for the odd picture lines and then one for all even picture lines. However, this technique has a major disadvantage; the larger the picture, the clearer the different picture lines. Moreover, when an image moves quickly, the time difference will cause the image with the even lines to be projected at a different location. This can cause artifacting ; Strange shapes in the image where especially the edges of objects are distorted. de-interlacing,a technique that is present on new TVs or peripherals such as Blu-ray players can solve this problem. With this technique, the even and odd lines are fully displayed on the screen in one go by means of software, which makes the image sharper and smoother looking. The more modern name for this technique is progressive scan . Newer films (especially Blu-ray films) and HD TV broadcasts often already use progressive scan in the recordings, so that de-interlacing no longer has to take place in your TV and the image, without the intervention of software or other techniques. , is displayed all at once on your TV.

In short, with progressive video all picture lines are built up at once. This is in contrast to interlaced video, where the even lines are displayed first and then the odd lines. But what is actually better? Perhaps the difference between interlaced and progressive is not that big, but in general progressive gives a calmer picture. With faster movement of the image, there is the possibility that you will see artifacts with interlaced, but this is especially a problem at lower refresh rates of around 25Hz. You will hardly see this phenomenon at 50Hz or 100Hz.

Explanation TV terms- Crosstalk

Crosstalk is a problem that you can sometimes encounter with new 3D TVs. When images for the left and right eye are not properly separated from each other, you can sometimes see ghost images (crosstalk). One eye then sees part of the image for the other eye. This gives a reduced 3D effect. Until now, this problem has mainly been observed with LCD / LED TVs and it must be said that this is not always the case, but can occur in certain scenes or light conditions.

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