[Пряник]

Oleg Nazarov, thanks!
I was reading about infrared film. And about the filters too.
Difference between the imager and infrared film is not seen, because both allow you to transfer thermal radiation in the visible spectrum.
The imager this function is performed by the lens of Germany and the matrix.
It may be that prolonged exposure and this is a fundamental difference. The imager there is no such function.
I ask You to tell which side is the source of infrared radiation: from the front (on reflection) or reverse (on clearance).
I get that a clearer picture is first uniformly warm side of the canvas to a temperature of 40-60 degrees Celsius and then put it aside and watch the cooling thermogram picturesque layer from the front side.
Sincerely,