Ultraviolet photography sensor will pick up reflected infrared radiation as well as ultraviolet, which may obscure the details that would be resolved by ultraviolet alone. Most types of glass will allow longwave UV to pass, but absorb all the other UV wavelengths, usually from about 350 nm and below. For UV photography it is necessary to use specially developed lenses having elements made from fused quartz or quartz and fluorite. Lenses based purely on quartz show a distinct focus shift between visible and UV light, whereas the fluorite/quartz lenses can be fully corrected between visible and ultraviolet light without focus shift. Examples
In the House of Stone and Light (album) As stated in the EPK, "Shape the Invisible" is Page's favorite on his debut album. As described by him in his video EPK: "My favorite song is 'Shape the Invisible', purely because of what the lyrics say. I was reading a book about Leonardo DaVinci and he mentioned that this shape the invisible in a sentence, and I thought what a great title. And at the time I wrote the song, there is as there always is trouble in the world, and I really wrote it as a wish song." Also stated in the EPK by Page, about the song