Re: Hie At Night

[Eckhard Stephan <eckhard.stephan@xxxxxxxxxxx>]

Rolland Elliott wrote:
> 
> > >kodak hie at night? i will be taking photos of lit
> buildings and> >such
> > >like.....will be using an R25 filter.
> 
>  1) There is relatively little IR light at night.
> Therefore IR film will give
>  you pictures similar to a regular black and white
> film. To obtain that  IR
>  look lean towards overexposure to give you halos
> around your light sources.
> 
As Andy Finney pointed out, it actually depends on what kind of
illumination is used for the buildings. I haven't done too much HIE
night shots yet (7 or 8 rolls). My experience is that normal street
lights as well as some (of course not all) of the spotlights used for
buildings emit a CONSIDERABLE amount of IR radiation. Electric bulbs
("Tungsten lights" in photographic jargon) actually emit more IR light
than visible light (you can find some information on the spectra of
different light sources in Laurie white's Infrared book). Therefore you
might well have to use HIGHER film speed settings for a Tungsten-lit
night scene than you would choose on a sunny day. 
For my night photographs I used a Wratten #25. It may not be necessary
to use any other than a UV-blocking filter (Skylight, yellow, ...), but
I got pleasant results with the red filter, so I will stay with it... I
took the Kodak HIE Data sheet as a first guideline. They recommend ISO
125 (metering WITHOUT !!! the filter) for Tungsten light, using a
Wratten #25. The pics I got using this combination were in general o.k.,
although some of them seemed a bit overexposed to me (very bright
halos). From what I've seen so far, I'd rather shoot HIE at ISO 250
(metering WITHOUT the filter !!!) with a Wratten #25. But especially in
this case, it's all a matter of personal taste. Maybe you'd like to have
more halos than I do. So, just BRACKET (+/- 2 stops on your first roll!)
- and see, which pictures you like best. BTW, if you print your negs
yourself, you can - to a certain degree -  "burn" away too exaggerated
halos by long exposure...

HAppy shooting,

Eckhard
-- 
========================================
*          Eckhard Stephan             * 
*          Freiburg (Germany)          *
*     eckhard.stephan@xxxxxxxxxxx      *	
*   http://www.eckhards-photobox.de    *   
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