Re: Rollei Infrared Filter Question

["Willem-Jan Markerink" <w.j.markerink@xxxxx>]

On  3 Mar 00 at 16:40, James Bielecki wrote:

> We have an old Rollei Series VI infrared filter that doesn't have
> any reference on it regarding it's IR designation.  I do believe
> it's IR cutoff point is 695nm (from an old book I found) and the
> fi ter is dark red, actually almost opaque.   Can any of you folks
> give me an idea of what factor it is?  89B?  87C?  

Schott 695 or 715, the latter being #89B....I have one such Rollei.
I believe Leica supplied the same color as OEM filter.

More insight in the different IR-color designations can be found in a 
chapter on my homepage, about filter transmission and equivalents:

http://www.a1.nl/phomepag/markerink/irfilter.htm

--                 
Bye,

Willem-Jan Markerink


      The desire to understand 
is sometimes far less intelligent than
     the inability to understand


<w.j.markerink@xxxxx>
[note: 'a-one' & 'en-el'!]
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