>>1540762An art lens is a non-standard camera lens intended to give photos special effects, like the "The Lomogon 2.5/32 Art Lens" or "The Lomography Daguerreotype Achromat 2.9/64 Art Lens," or even DIY art lens like what I use. They can be used for lomography or standard non-lomography photos, it just depends on the special effects. There are also "Art Lens" branding by companies that just label some of their best normal lenses as "art lenses" to get extra consumer bux.
Here's an example of what one of my more extreme art lenses can do. They are difficult lenses to use correctly so getting images considered "good," in an artistic sense, takes a lot of practice and luck.