Hello All,
I'm looking to make a UV-pass filter for a miniHID (Mag D Host). It's been done before, but rather than resurrect an ancient thread, I thought I'd post a new one.
Other CPFers have used UV photography filters (49mm) that fit nicely into the Mag D Accessories filter holder. Since those filters have increased greatly in price over the last few years, and I'd be plunking down some cash anyway, I thought I'd go a little further. Rather than fit a commercial filter into the rubber filter holder, I thought I'd try to make my own window from UV-transmissive glass and use it in place of the normal boro miniHID window. One other member that I could find had done the same, and the thread is here: http://www.candlepowerforums.com/vb/showthread.php?103682-UV-lens-for-Mini-HID
Most filters I've found available are made using Schott UG-1 (spectral properties here: http://www.schott.com/advanced_optics/english/download/schott_uv_bandpass_ug1_2008_e.pdf)
But Hoya glass seems to be a bit more specific to the UV region of the spectrum, and absorb more violet and red (so hopefully a true UV only source). Hoya offers both U340 and U360. Looks like U340 gives adequate transmittance in the 365nm region, but does a better job of blocking visible light (and so, is the better glass). U340 spectrum is here: http://www.hoyaoptics.com/pdf/U340.pdf
I guess the questions I still have are these:
1. U340 is sold in a 2" by 2" square -- will that be large enough to round into a Mag D window? Anyone know the definite dimensions?
2. The U340 square is 2.5 mm thick. I know that's thicker than the Borofloat Mag D window, but does anyone know by how much? Will that 2.5 mm allow the bezel to screw down?
3. Any tips or suggestions on filing/shaping/rounding glass?
4. Did I miss anything obvious here? The U340 is really pricey, so I want to make sure I get it right the first time.
Thank you much for the help!
I'm looking to make a UV-pass filter for a miniHID (Mag D Host). It's been done before, but rather than resurrect an ancient thread, I thought I'd post a new one.
Other CPFers have used UV photography filters (49mm) that fit nicely into the Mag D Accessories filter holder. Since those filters have increased greatly in price over the last few years, and I'd be plunking down some cash anyway, I thought I'd go a little further. Rather than fit a commercial filter into the rubber filter holder, I thought I'd try to make my own window from UV-transmissive glass and use it in place of the normal boro miniHID window. One other member that I could find had done the same, and the thread is here: http://www.candlepowerforums.com/vb/showthread.php?103682-UV-lens-for-Mini-HID
Most filters I've found available are made using Schott UG-1 (spectral properties here: http://www.schott.com/advanced_optics/english/download/schott_uv_bandpass_ug1_2008_e.pdf)
But Hoya glass seems to be a bit more specific to the UV region of the spectrum, and absorb more violet and red (so hopefully a true UV only source). Hoya offers both U340 and U360. Looks like U340 gives adequate transmittance in the 365nm region, but does a better job of blocking visible light (and so, is the better glass). U340 spectrum is here: http://www.hoyaoptics.com/pdf/U340.pdf
I guess the questions I still have are these:
1. U340 is sold in a 2" by 2" square -- will that be large enough to round into a Mag D window? Anyone know the definite dimensions?
2. The U340 square is 2.5 mm thick. I know that's thicker than the Borofloat Mag D window, but does anyone know by how much? Will that 2.5 mm allow the bezel to screw down?
3. Any tips or suggestions on filing/shaping/rounding glass?
4. Did I miss anything obvious here? The U340 is really pricey, so I want to make sure I get it right the first time.
Thank you much for the help!
