Re: E-6 as IR filter ??

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

On 22 Nov 98 at 10:21, Andrew Davidhazy wrote:

> First, the spectral transmission of dye based photographic materials when at
> maximum density leaves a lot to be desired in terms of performance
> particularly as it pertains to minimum density and also in terms loss of
> optical resolution and finally in terms of sharpness of cutoff.

I believe I recently forwarded a message from sci.optics that had 
some density data for this E-6 trick....
 
> None of this negates the possibility that the "look" may be "more IR-ish" but
> those are subjective and not objective terms.
> 
> Finally, as the self-appointed "inventor" of the technique of placing filters
> between the film plane rails of cameras, I would definitely NOT recommend that
> you try placing the E-6 material between the film plane rails of your camera
> since the likelihood of preventing the free movement of the film will probably
> be adversely affected. This is not so much the case when you use very thin
> Wratten filters or similar foil filters but E-6 films are significantly thicker
> (usually). In any case, I would carefully test the procedure first and not
> unduly force the wind and rewind leversin your camera ... and if all you have
> is motor driven advance and rewind ... well, then I'd be even more careful.

No problem in that department....the only polyester #87C foil option I 
*can* offer is a 0.4mm thick quality, and one that has been sitting 
happily inside my EOS-1 for nearly three years now, simply attached 
on the left and right with small strips of clear office tape (single 
sided).

I intend to do the same with my Mamiya RB, and dedicate one
revolving-back unit (not the back itself, but the detacheable
rotating part) for this filter....it requires more complex tinkering
to get the filter inside, but should then work just as charming as
in my EOS-1....there are not that many smart solutions either to
mount opaque filters to the 37mm fisheye....8-)) 

--                 
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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