Claire et al.
I don't have the coated condensors. I spoke with Jensen sometime ago in regard to UV transmission of the regular Durst condensors and he did say that they were largely transparent to UVA with a loss of perhaps 1/3 stop. This may not address their performance when used with a point light source however.
I recognize that the opal lamps are semi diffuse and with the improvement I have seen over a pure diffusion light source, I would be very prone to move to a pure point light source at some point.
Do you have the conversion that Jensen has for their replacement lamp? I wonder because their transformer for that lamp also has voltage adjustment.
If that is the case, Jensen told me that the transformer output voltage for their lamp was 82 volts with a 1200 watt lamp.