Why you need to use an Infrared filter for 'X ray effect'?

Why you need to use an Infrared filter for 'X ray effect'?

Sony has changed the Nightshot feature a few times during production.
The first Sony camcorders could shoot Nightshot in the day. Then Sony
found that people were using the camcorders to see through some
clothing, so they changed the camcorders to have a fully open aperture
in Nightshot mode. This meant in bright light, the picture is
overexposed. Some of the most recent camcorders from Sony are somewhere
in-between. One recent camcorder we have tested limits the minimum
aperture but still adjusts the aperture wider. Interestingly, the result
is that in Nightshot mode during daylight, the picture is overexposed
without a filter. But, using Nightshot in daylight with an IR filter
works! Perhaps Sony has realized that this feature helps sell cameras. 

All Sony Digital Video Camera with the Nightshot/Nightshot Plus/Super
Nightshot/Super Nightshot Plus feature are capable of achieving the
X-Ray effect when used with the GTS2 Infrared filter. Seeing is
beliveing. This infrared filter will filter out 99% of light seen by
naked eye only allowing infrared light thru. Technically the naked eye
can see 100% black with the help of this filter. Because with the night
shot function on the naked eye cannot pick up the high contrast black.
So with the GTS2 Infrared filter and your night shot function on, it
will help u see title of a book with a piece of cloth place over it thus
the x-ray effect.
  
Available in 25mm, 30mm, 37mm and 58mm GTS2 Infrared filter is made with
High Grade Imported Infrared glass from JAPAN. Specially mounted in a
Silverish Grey ring to match your Sony DV cam. This filter includes a
round/flip open plastic carrying case.

Buy it online at www.infraxfilter.com

 

You can do the same thing by using the Heliopan 1000nm IR filter that
can be ordered from any camera store in all sizes from 19mm to 105mm.