Valve’s 3D artist, Karen Laur, has shared numerous original texture sources and photo references for the first classic Half-Life. This texture reference pack is 510MB in size, and you can find below some download links for it.
In theory, modders can use this pack in order to overhaul a lot of the game’s blurry textures. Truth be told, we’ve already gotten an AI-enhanced HD Texture Pack for Half-Life Source and the original Half-Life. By having access to the reference photos, though, modders could further improve the game’s textures.