High-definition photos come from professional photography, and the cameras are all high-pixel digital cameras or professional-grade traditional cameras, even landlines. The digital photos taken are tens or hundreds of megabytes, or large-size reverse films (positive films, digital photos are obtained through professional scanning). The original file is very large and has been professionally color-corrected, so even if it is reduced to a small photo for online use, it is still very clear because of its good foundation. At present, the production of super-large photos still depends on traditional cameras, because the pixel limit of digital cameras is far from the resolution of traditional photos (especially positive photos). The negative (positive) photos on the super-large billboard on the roof are bigger than the photos we usually see (A4, A5, etc.). Unless you are prepared to take photography as a career, the investment of these professional cameras ranges from tens of thousands to hundreds or even millions, and not everyone can try it at will. High-definition wonderful photos need a lot of investment to support.