Infrared film senses heat.

Colour infrared provides a slide that gives a colour shift. (It has been years since I used that film, because there are maybe three labs in North America that will process it at a reasonable price).

Where the heat is on black and white film is where the print will show darkest. It can be used to take a picture of yer house so you can see where your main areas of heat loss are. As an incidental thing.

On the lens of the camera you should see a curved line that goes fron the camera body to the end of the lens. That line is the black and white correction line for focussing b and w infrared film. You focus the camera normally--that is, look through your 'lens' and focus. Hold fairly still. Take the lens and without changing the positioning of the camera, turn the lens so that the curve line meets with the 'notch' line on the camrea. That will have focussed you for the shot. When you look through the lensd to take the picture, it woill appear to be out of focus. It would be with any other film but b and w infrared.

I realize my explanation of the curved line thing leaves lots to be desired. If yer gonna shoot infrared, ask at the camera store. Someone there should help you.

BM