High Speed Infrared film?
Peter Tkacz
infrared film. I have shot black and white, as well as color neg and
positive film, but never infrared before. The film isn't cheap, and I would
hate to waste it. I did today purchase two rolls of film and a Iford SFX
Cokin "P" filter. If I can get some answers, I hope to maybe get some
interesting photographs. Who knows, if things go good, it might be an
interesting film to add to my list of films that I like to use.
The package it reads KODAK High Speed Infrared Film, but the inside of the
box reads ISO 80 with no filter??? I'm assuming that because it's really
sensitive to heat, so that's where the word high comes from.
So why is a film that is rated ISO 80 refered to as high speed???
As for the Ilford SFX cokin "P" filter, it is an awefuly dark red color, and
the package states that it is rated at a filter factor of 16. What does
this filter factor mean/indicate?
I did take an incident meter reading with sunlight falling directly on the
meter and got a reading of f 2.8 at 1/3000s, but when taking a reading with
the filter in front, I got a reading of f 2.8 at 1/180s. Doing some math, I
find there being a 4 stop difference between both readings, a factor of 16
times. Does one stop translate to a filter factor of 4?
The gentleman at the camera store stated to do alot of braketing, the film
canister box states to bracket extensively, but given what is known, should
one be able to not bracket as much and get good overall results?
When taking photographs, how should I best determine a correct exposure for
an image? I assume that I should probably set my film speed to ISO 40 or
ISO 80, and meter through the lens, or increase my exposure by 4 stops after
taking a meter reading with an incident meter?
Has anyone had good experience with this film?
Joshua Putnam
ptk...@cogeco.ca writes:
>The package it reads KODAK High Speed Infrared Film, but the inside of the
>box reads ISO 80 with no filter??? I'm assuming that because it's really
>sensitive to heat, so that's where the word high comes from.
>So why is a film that is rated ISO 80 refered to as high speed???
Because it replaced Kodak Infrared Film, which was much slower.
It's still the fastest common infrared film, much faster than
Konica 750 or Maco.
No infrared film is particularly sensitive to heat for recording
images, though they're somewhat more sensitive to heat when it
comes to fogging. The images recorded by Kodak's HIE are well
above the heat spectrum -- an object has to be close to 1000 F
before it starts getting very bright in HIE's spectrum.
>The gentleman at the camera store stated to do alot of braketing, the film
>canister box states to bracket extensively, but given what is known, should
>one be able to not bracket as much and get good overall results?
>
>When taking photographs, how should I best determine a correct exposure for
>an image?
Personally, I use Sunny 16 and skip the meter for most of my IR
work. I don't use that particular filter, so I don't know what
base exposure I would use for it. Here are the exposures I use
with no.25 red and no.87 opaque filters:
HIE w/25 Red Filter
Direct Sun 1/125 @ 16
Hazy Sun 1/60 @ 16
Light Cloud 1/60 @ 11
Moderate Rain 1/30 @ 8
Thunderstorm 1/15 @ 5.6
HIE w/87 Gel Filter
Direct Sun 1/60 @ 16
Hazy Sun 1/30 @ 16
Light Cloud 1/30 @ 11
Moderate Rain 1/15 @ 8
Thunderstorm 1/8 @ 5.6
--
jo...@phred.org is Joshua Putnam
<http://www.phred.org/~josh/>
Updated Infrared Photography Gallery:
<http://www.phred.org/~josh/photo/ir.html>
Hank Scorpio
http://www.a1.nl/phomepag/markerink/mainpage.htm
"Peter Tkacz" <ptk...@cogeco.ca> wrote in message
news:FEl09.106206$Yt.40...@read1.cgocable.net...