The higher quality the Ultraviolet (UV) source, the better fluorescent minerals look. Critical factors include; filtration (Hoya glass vs Plastic filter or lens), lamp wattage, bulb composition, lamp construction, wave length and distance of lamp to specimen. For best results with any UV source, observe against a black, non-fluorescent, non-reflective background, in complete darkness with eyes adapted. To dark adapt your eye's, you must be in complete darkness for approximately seven (7) minutes. The photos here were taken using a Shortwave (SW), Midwave (MW) or Longwave (LW) lamps, metered and exposed to show fluorescent response to its best advantage. The more powerful the ultraviolet lamp, the brighter the fluorescent response. Low cost ultraviolet lamps that purport to provide shortwave and/or longwave will not adequately fluoresce most minerals. Neither will very low wattage shortwave lamps. The filter is the most expensive component of a lamp and for a low price it will not be a quality filter - it will either permit too much visible light to pass through or not enough ultraviolet light. The second most expensive component is a high quality (UV) bulb. Cheap out on these two critical items and you will become disappointed with collecting fluorescent minerals.  I will indicate which wavelength is appropriate for the particular specimen being offered at auction and wavelength (SW/MW,LW) used as well as the wattage of UV lamp used for photography. I use a 9 watt WTC lamp to illuminate most specimens.