Non-4K content may appear less clear on a 4K TV compared to a regular HDTV due to the difference in resolution. 4K TVs have a higher resolution than regular HDTVs, meaning they have more pixels on the screen. When non-4K content is displayed on a 4K TV, the TV has to upscale the image to match the higher resolution of the screen. This process can result in a loss of detail and clarity, making the image appear less sharp and clear than it would on a regular HDTV.
However, it's important to note that not all 4K TVs are created equal. Some 4K TVs have better upscaling technology than others, which can help to improve the clarity of non-4K content on the screen. Additionally, some 4K TVs have features like high dynamic range (HDR) that can enhance the overall viewing experience, even with non-4K content. So while non-4K content may appear less clear on a 4K TV compared to a regular HDTV, the extent of this difference can vary depending on the specific TV and its features.