Re: >>> Taichi Kato <tkato@kusastro.kyoto-u.ac.jp> 09/16 10:33 AM >>> Re: UV visibility (Re: [vsnet-chat 1284] Re: V3885 Sgr, this season) Once in my career in physics experiment course, I could visually measure a number of violet lines through a visual spectrometer, but don't remember their exact wavelengths. // Dear Taichi, I bet you were looking at Hg lines around 404.7, 407.8 and 435.8 nm. They are violet to violet/blue and supposed to be visible. I use them a lot to calibrate wavelength functions for monochromators.. I did some superficial testing yesterday and discovered that quite a number of materials fluoresce under UV -A light, not just paper.. and perhaps that's why UV seemed visible at the time. It's not straightforward to cut out a narrow bandpass with interference filters only because of the 'long' tails they have. With my powerful UV source I might add a monochromator to do that. Later more on that, hopefully... Regards, Berto