Filming X-Ray Without a Filter
This is largely considered to be impossible but recent testing has proved it can be done.
I am aware this appears to contradict what I say elsewhere but please note that all other x-ray filming discussed refers to filming under sunlight.
Testing here was done with a Sony Handycam.
When filming under certain lighting conditions, such as darkness illuminated with the NightShot illuminators (or other infrared light) or light emitted by most standard tungsten filament light bulbs (such as ordinary household lights) there is a great deal more infrared light present than visible.
This has a similar effect to using a filter in daylight - the level of visible light is low but the level of infrared light is high.
The results vary drastically, but I have done some testing with a subject in a dark area outside illuminated with the NightShot lights in the camera and found it worked quite well. Fitting any filter simply made the picture darker by varying degrees (depending which filter).
The same subject standing under a standard light-bulb showed a less impressive, but still apparent, level of x-ray. The NightShot lights hardly made any difference in this setting. Fitting a filter made only a slight improvement. A Wratten 87C and a B&W #093 produced a very slight improvement but a Hoya RM100 made the picture too dark (the RM100 is best suited to bright sunlight).
Under fluorescent lighting, no effect was seen at all and fitting any filter made the picture almost black.
Placing the infrared filter on the camera showed that the fluorescent light gave off almost no infrared at all (which explains why they burn so much cooler), while the standard light bulb glowed very brightly indeed.
Don't expect fantastic results using this method. It does not compare with a subject illuminated by sunlight and filmed with a good filter such as the B&W 093 or the Hoya RM90.
This method of filming could be used to confirm the effect to yourself before buying an expensive filter if you are having doubts though.