Re: HIE UV photography.

["David J. Romano" <romano@xxxxxxxx>]

To throw a few cents more into this, consider that the spectral
sensitivity curve of HIE shows that it is about .75 log (5.6x or 2.5
stops) more sensitive to UV than to IR. If you are using a UV short-pass
filter with the same type of curve as your typical IR filter, then the
required exposure will be this much less. This is a practical way to
compare the UV vs IR sensitivity for this film. To compare the UV
sensitivities of this film and the Fuji 400T slide film is another
matter, but I wouldn't begin to try predict it without knowing the
sensitivity to UV light relative to visible light. Fuji 400T slide film
may have UV blocking filters built in.

Dave

Jason Revell wrote:
> 
> Dan,
> 
> Although I have never needed to take these pictures (in B+W), what you are
> saying does of course work quite well.  Transmission of the filter is
> slightly different from what quote (from my info anyway).  Its transmission
> peaks at 360nm (65%) and drop down sharply after that (400nm has only 10%
> trans.).  The filter also allows a small amount of light in the IR part of
> the spectrum (from 700nm and beyond) but this will have little affect on the
> final image unless it's for scientific use (never higher than 20%).
> 
> You may also find that the exposures are quite long.  Last time I used the
> 403 filter I had an exposure of 3 minutes at f4 using Fuji 400T slide film
> (object light with 4x4ft BLB tubes at 3 ft distance).  Although HIE should
> give you a slightly shorter exposure I would guess you would be looking over
> 1 minute.
> 
> Certainly give this a try and let me know if you get any results.
> 
> Jason
> 
>                 -----Original Message-----
>                 From:   Daniel Flather [mailto:pincher@xxxxxxxxxxxxxxx]
>                 Sent:   12 February 2001 22:33
>                 To:     infrared@xxxxx
>                 Subject:        HIE UV photography.
> 
>                 Hi,
> 
>                         Has anyone here ever used a UV Black 403 Glass
> Filter with Kodak HIE?
>                 This filter cuts light above wavelengths longer than 360nm.
> Since HIE
>                 has a spectral sensitivity below 360nm it should be possible
> to get
>                 images of ultra-violet light??  And the elements in a lens
> only cut out
>                 wavelengths below 280nm (I think), this should work.  I
> should be able
>                 to photograph wavelengths from 280nm-360nm with this filter.
> 
>                         Where can I go to see images of this if it has been
> done?
> 
>                 -Dan
>                 Canada.
> 
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