Re: Kodak High Speed IR film

leban (HLEBANPHOT@compuserve.com)
Tue, 07 Oct 1997 07:18:54 -0400

Chris Fox wrote:

>I really like the look of IR photos, but I've had much more success with
35mm
>than with larger formats.

>I bought a box of larger format film, and found that
>a) I had no way of working out where to focus (on 35mm I can use the red
dot >for
>IR on the lens). With large format cameras with long lenses, the focussing
can
>be very critical
>b) With a 35mm camera you can shoot off a range of exposures to make sure
>that
>you've got the right exposure for IR. This is less easy with large format,
>although I'm sure that with experience you start to know what the correct
>exposure will probably be

>If anyone has suggestions for ways round this, please let me know (I've
still
>got quite a few sheets left to use)

>- Chris Fox

Chris

IR-Photography is a very sensitive Medium but with the the right discipline
you can control it.

for the focusing : I think on the film data sheet you can find a formula to
get the right focus difference also with long lenses.

In my case I spread the focusing 1-2% of the focal lengh (e.g. 240mm lens -
I give 2-5mm more = quarter turn of my focusing knob ) f-stop is normally
22-32
Try it .

for the exposure:
Film speed and exposure depend from the developer and the process you use.
For my alt-photo work I developed the HIE 4x5" in a self made reversal
process to get slides for enlarged negatives. The advantage of this process
is tuning of film speed to stunning 1600-6400ASA (metered through a WR25
filter ).

If you want negatives you can reach 400-1200 ASA in diverse developers.
But you have allways to be sure what (IR)-situation you have and what your
lightmeter can see and with this two terms you should come to a success .

In the appendix you can look about my reversal process and how to recognize
the (IR)-light situation.

Greetings

Harald Leban
hlebanphot@compuserve.com

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