[Leica] IR Filters

[henningw at archiphoto.com (Henning Wulff)]

>   Hi
>   
>   I?m going to register the M8 and ask the filters
>   
>   I?m planning in a (long) future to buy the new 
>tri elmar so one of the filters will be for it. 
>(By the way what is the measure of the filter do 
>the tri elmar 16,18,21)
>   
>   I have some other leica lens but I?m not sure 
>in witch it will be more necessary.
>   
>   When is the IR problem more likely to appear? Exterior? Interior?
>   
>   If it?s interior the best option will be for the noctilux (58mm).
>   
>   Any advice?
>   
>   B regards from Portugal
>
>

The magenta cast will come up mainly when there 
is a high proportion of IR to visible light. That 
occurs primarily under incandescent lighting, 
secondly in sunlight.

If you shoot under fluorescent lighting, you 
wont's see it. If you shoot outside on cloudy 
days, the effect is minor.

Since black subjects are supposed to have 'no 
colour', the magenta effect shows up soonest on 
black subjects that reflect IR. It can be 
synthetic clothing, but also cotton t-shirts show 
the effect. Since our perception and 
differentiation of skin colour is quite acute, 
the magenta effect often causes an unpleasant red 
or pink flush to otherwise neutral skin.

If you intend on shooting colour indoors under 
incandescent lighting, get the filters for those 
lenses that you will use under those conditions. 
That's where you will notice the greatest benefit.

-- 
    *            Henning J. Wulff
   /|\      Wulff Photography & Design
  /###\   mailto:henningw@archiphoto.com
  |[ ]|     http://www.archiphoto.com