The cost has dropped to several hundred dollars per unit, but the benefits are many particularly during development by inspection (DBI).

I have not encountered any specific adverse effects John with using these devices, but the engineer in me seems to want to make damn sure that the base fog does not kick up even slightly. I realize that even a low wattage green safelight could have the same effect with the conventional methodology. Assumning a conclusion has its risks and with the cost of ULF film I just want to eliminate any operating variable to the degree possible.

Guess I will run a few sheets of 4x5 with and without and do some density measurements.

The next alternative I will try is to leave the battery power off of the light gatherer and the IR source completely and use an external panel IR source. The monocle works just fine with this external source of IR.

Cheers!