To see a Color Infrared Ektachrome image of this same species of butterfly click here: Color IR Fritillary

The "Action Infrared" method (see Davidhazy below) was used by placing a Wratten #87 filter gel behind the shutter but in front of the film plane. This method allows you to see the image via the SLR's mirror.
I don't know how that spiral artifact came about, but it might have been by scanning the negative on a flat bed scanner. I may try to remove it with Paint Shop Pro 7 one of these days.
This photo is hyperlinked to the color hummingbird section. Click on the photo to jump over to the color hummingbird photos.
Olympus OM1n camera on tripod with the mirror locked up, 1/500th second exposure, f8
Upper Newport Bay (Back Bay), Newport Beach, California
The anti-halation layer of normal films prevents photons from bouncing through the film emulsion layer repeatedly.
The vertebrate retina has the pigment epithelium (P.E.) which uses melanin pigment to accomplish the absorption of stray photons. In dark adaptation the pigment epithelium retracts allowing the scant photons to maximize their effect on the retinal receptors (Rods & Cones).
In a sense the P.E. is the "antihalation layer" of the retina.
For even greater nocturnal sensitivity many animals including cats and dogs have a special reflective layer called the tapetum lucidum behind the retina. It is often apparent at night when the animal's PE (pigment epithelium) is retracted and light from a flashlight is cast back at an observer or photographer. As far as I know, humans do not have a tapetum lucidum. Many of us; however, are familiar with the photographic phenomenon known as "Red-Eye". It is similar except that the red color is actually due to the blood in vessels behind the retina and PE, and is usually only seen with direct photo-flash, close to the camera's lens.
While I've always thought that I wanted a shift lens for architectural photography, I think this photo is better without one.
The hands are holding tiny adult frogs that live in the Mojave desert. Were water plentiful, I am told, one frog would be more than a handful. Metamorphosis in tadpoles can be accelerated artificially with the hormone thyroxin resulting in similar size reduction in the adult frog -- so it is fun to speculate; however, the frogs in this photo are tiny adults and their small size I've been told, is an adaptation for the short rainy season.

This graph was scanned from a dot matrix printout that I made using a Beckman DU 64 spectrophotometer. I simply positioned the filter gel in the light beam and made a full spectrum.
This view was made with the same 28mm lens and camera as in the two buildings view shown previously.
The "pits" are the dark spots in front of and below both eyes and enable stereo infrared vision. Pit Vipers like this "Mojave Green" (Crotalus scutulatus) evolved a natural "forward looking infrared" system. It allows them to strike with deadly accuracy in what would otherwise be absolute darkness.
Infrared Tailed Hawk:
An Action Infrared Photo of a Red Tailed Hawk flying overhead. Photographed
with my Olympus OM1n with a 500 mm "Mirror Lens" with the Kodak Wratten #87 filter behind the mirror
but in front of the shutter. This technique makes infrared photography such a "snap" !
High Speed Infrared film must be dark loaded, unloaded and developed in total darkness ( hint: use a film changing bag), and it is often difficult to determine the proper exposure; however, the results are often worth the extra effort !
Infrared Self Portrait :
Photographed with my Fuji FinePix S5000 + Hoya R72 filter + Olympus IS/L 0.8X Wide Angle converter lens. This image was made in bright sunshine on a cold Winter day. My jacket is red and
the sweatshirt is a dark burgundy color. In normal visible light the dark mountain climber sunglasses would be much more opaque. This image was processed with Adobe Photoshop compression and Auto Levels.