- Sep 2, 2001
- Stillwater, America
You really can. Dichroic filters are particularly easy to discern from regular tint when looking at a bulb or lens such treated.You can't look at a bulb and determine what type of filtering the blue on the bulbs are doing.
Removing light does not make a bulb brighter. Not even if the word brighter is in quotes.Most high quality bulbs use that blue as an interference style filter as to actually remove the blue wavelengths thus making the bulb "brighter" by only projecting desirable wavelengths.
The blue coating on the bulbs discussed in this thread is a simple filter, not a dichroic coating.
*thenIf what you're saying is true, than the light would be perfectly white, which it's not.
Light output from a properly-fed halogen filament is already almost "perfectly white" in the first place.