[Leica] Kodak HIE and Leica lenses

["Jack F. Matlock" <jfmatlo@ibm.net>]

On October 28 Derek wrote:

"I've been experimenting with IR film lately, and have a 
question
regarding IR focus in the lenses"

I, too, have started using HIE when I want special effects on 
landscapes.  I have been using the 35 mm Summicron ASPH on an M6 
and have had no trouble with the focus.  (Normally, I am focused 
on infinity.)

I have used both the Leica IR filter (withdrawn, but available 
used) and the Leica red filter with similar results.  My 
experience has been that the film is a lot faster than the ASA 
25 Kodak recommends.  In any event, it is imperative to bracket 
exposures since the intensity of IR "light" does not vary 
proportionately with visible light. My best negatives in bright 
sunlight have been around 1/250 at f:11.  I develop in HC 110, 
dilution B.

One thing to remember:  it is very important to follow the 
instructions to load and unload the film in total darkness.  I 
recently absent mindedly took the rewound cartridge out in 
daylight and 4 frames were ruined.  If you are loading or 
unloading the camera in the field, take along a changing bag.

Jack