I'm still working my way up to ULF (I have an 11x14 but don't use it much). I shoot various large/ultra-large formats because I got into contact-printing alt-process materials and it's the way to have images in the size you want them. I'm working on building a dedicated vertical portrait-format 12x20, which I already have the lens for - a 24" (600mm) Docter Optic Apo-Germinar f9.