Ilford SFX 200 is
an extended red sensitivity film. It's not a true infra red film but
shares characteristics with those films.
I made a very deep red filter out of a red filter and a blue filter for
the photo to the left. Exposure was about 90 seconds at f22 in
bright sunlight.
This was done with
a red filter. Exposure was one second at f22.
Two minutes at f22. Very deep red filter.
Red filter. One
second at f16.
Very deep red
filter. About 90 seconds f22.
Red filter. One
second at f22.
Graflex Crown Graphic 23 with 90mm Optar.
10 minutes in HC110(b.)