Re: BTFR-Filters

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

On  5 Sep 99 at 10:24, Oliver Pettenpaul wrote:

> Hi everyone !
> 
> I'm more and more attracted by the idea of mounting an opaque IR-filter-foil
> between the film rails of my trusty Canon-A1 which I use for infrared work
> exclusively. The hassle with my srew-in 87C is just too much for an impatient
> person like me ;)
> So my question to the list:
> Which filter foils are availabe, which do you use and have proven themselves
> suitable ?

I have several colors available as polyester foil, including #8,
#12, #16 & #21 (for EIR), and #25, #29, #89B, #87 and #87C. The
latter only in a 0.4mm thick quality, which makes it less flexible,
but also more resistant against scratches, as well as easier to
clean....all others are 0.1mm thick. All are US$0.50 pro square 
centimeter.
Darker than #87C (#87B and #87A) is only possible in gelatine (not 
from Kodak, they don't make them anymore).

> And to those in the area around Germany: 'Brenner Fotoversand' offers an 
> 'Infrarot-Filter-Folie, extrem dunkelrot... 80mmx80mmm'. Has anyone tried 
> this ? What's the equivalent Wratten# of this foil ?

Many many moons ago, I ordered this particular filter, and was
dissapointed to find out it was still gelatine, and far from
opaque....I still have some sheets left somewhere in my pile of
stuff, but I recall that it was closer to #29 than to #89B. Poor
solution IMO. I think they called it #83 or #82....and AFAIK, this 
isn't even a Wratten code (at least not a matching one)....I think it 
was made by Orwo, so it might use an odd old-German (Agfa?) filter 
code....


 

--                 
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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