[Leica] IR Filters

[red735i at earthlink.net (Frank Filippone)]

As I understand the problem... it occurs when there is a piece of black 
synthetic clothing present.  The IR reflection off the
synthetic part of the cloth is enough to be recorded by the sensor in an 
erroneous way ( to our eyes), giving a magenta cast to the
black sweater.

As far as I can tell, the effect is "available" anywhere.  It is the source 
of light plus the type of material that makes it go
astray.  It is not an "indoor" or "outdoor" effect.  You need filters all 
the time to ensure there willnot nbe a problem.

The other part of the question, in my mind,  has to do with the color of the 
clothing... is it black only or is the effect most
obvious with black, but always present, in less obvious amounts,  
otherwise..... 

All of which is why I think the addition of a filter in front of the lens is 
a solution that is not-consumer friendly.  The filter
should be included in the coating on the sensor cover plate.

Question... I remember wedding photographers having trouble with certain 
situations where the color of the white dress did not work
on certain films.... something to do with optical brighteners in the cloth 
of the dress.....   Can someone comment on this old
phenomenon and its solution?  

Frank Filippone
red735i@earthlink.net