Question 1

What is chroma subsampling, and why does text look bad over HDMI?

Accepted Answer

A compression technique that stores **colour information at lower resolution than brightness**, exploiting the fact that human vision is far more sensitive to brightness detail than to colour detail. It is invisible in video and destructive for text.

**The mechanism.** An image is separated into **luma** (brightness) and **chroma** (colour). Luma is kept at full resolution; chroma is sampled less often and shared between adjacent pixels.

**The notation** describes how much: **4:4:4** is no subsampling, full colour resolution. **4:2:2** halves colour resolution horizontally. **4:2:0** halves it both horizontally and vertically, storing a quarter of the colour information.

**Why it works for video.** The eye's colour resolution genuinely is much lower than its brightness resolution, so discarding colour detail in moving photographic images is close to imperceptible while saving an enormous amount of data. **Virtually all video you watch is 4:2:0** — broadcast, streaming, Blu-ray.

**Why it destroys text.** Text is **high-contrast, thin, and coloured**. Red text on a black background, or coloured syntax highlighting, consists of fine detail that exists precisely in the colour channel. Subsampling smears it, producing fringing, blurred edges and unreadable small type.

**This is why a television used as a monitor frequently shows poor text.** The set is applying 4:2:0 processing appropriate for video, and the text suffers.

**How to fix it:**

**Enable the television's PC or Game mode**, which on many sets switches to 4:4:4 and disables processing.

**Check the HDMI input setting.** Many televisions have a per-input option — frequently called Enhanced, Deep Colour or HDMI UHD Colour — that must be enabled for full bandwidth. Without it, the set falls back to subsampling.

**Check bandwidth.** At high resolutions and refresh rates, 4:4:4 requires more bandwidth than the cable or port supports, so the source reduces chroma automatically. A better-specified cable or a lower refresh rate can restore it.

**Label the input as PC** on sets that behave differently by label.

**For photographic content it makes no visible difference**, which is why it goes unnoticed until text appears.

Question 2

Should I use a TV as a computer monitor?

Accepted Answer

You can, and for some uses it works well — but several differences make a TV a poor desk monitor and a good living-room display, and they are not obvious from the specifications. Where TVs fall

Question 3

What is bitrate, and why does it matter more than resolution?

Accepted Answer

Bitrate is how much data is used per second of video — and it frequently determines picture quality more than resolution does, which is why a 4K stream can look worse than a Blu-ray at 1080p. The

Question 4

How does a camera sensor capture colour?

Accepted Answer

It does not, directly — sensor pixels only measure brightness. Colour is produced by placing tiny coloured filters over them and then reconstructing the missing information computationally. The Bayer

Question 5

How does a TV upscale content?

Accepted Answer

By inventing pixels that were never captured — a lower-resolution image has to be expanded to fill a higher-resolution panel, and how convincingly that is done is one of the biggest differences

Question 6

Can you actually see the difference between 4K and 8K?

Accepted Answer

It depends almost entirely on screen size and viewing distance, and for most living rooms the honest answer for 8K is no. The terms first. 4K in consumer televisions means UHD, 3840 × 2160 — four

Question 7

What is HDR on a television and do I actually need it?

Accepted Answer

HDR expands the range between the darkest and brightest parts of an image, and widens the range of colours available. It is a more meaningful improvement than resolution for most content, because the

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