This restriction poses a problem for daytime IR UFO spotting, so with the aid of an infrared pass filter that restricts visible light and infrared light up to a required frequency, the exposure levels can be controlled again, allowing the nightshot feature to be used in bright sunny conditions. This method of filming in infrared is the preferred and most popular of choices, but still poses a couple of issues. The first and pretty obvious issue is that you are unable to quickly revert back to the visible spectrum if a possible 'cloaked' UFO is spotted as the visible spectrum is blocked. One of the aspirations of an infrared UFO hunter is to prove the UFO that they themselves have captured wasn't visible to the naked eye. It can be done with the IR pass filter method, but it's a time consuming, fumbling task. And if your lucky enough to have spotted a potential UFO, capturing some quality footage is of the up most importance, the last thing you want to do is ruin it by fumbling around removing lenses and flicking nightshot switches, it just takes too long.
The second and most important issue with using the IR pass filter method is not only the visible spectrum be being blocked, but also the all important near infrared light is too, infrared light wavelengths up to whatever the lens is rated at . If a Sony camcorder is using a 920nm IR pass filter to control exposure levels, all visible light and infrared light up to 920nm are refused entry into the camcorder, purely for exposure reasons. The problem with this is, your relying on a UFO that isn't reflecting visible light to reflect IR light wavelengths higher than the 920nm IR pass filter used to be seen. This will make way for a lot of theories that suggest UFOs can sometimes just disappear or even appear from out of nowhere.
One way to get around the issue that IR pass filters pose is to use neutral density filters. These filters can control exposures levels without blocking specific wavelengths of light. Acting like how sunglasses work, they dampen down exposure levels, but without effecting colour or restricting IR light. Using these filters that come in a variety of strengths including ND2, ND4, ND8, etc, allow a camcorder using IR nightshot to be used in daylight conditions, but with the added bonus of switching back and using the normal visible spectrum.
On 17th May 2010, 7pm, I was filming the skies in infrared using Sony's nightshot mode and a ND4 filter in place. The UFO that I capture clearly reflects light, also shows no signs of a conventional craft. What I was able to do using this ND filter method, is promtly switch over to the visible spectrum, just to see whether the bright object that I had captured in infrared would also remain in the visible spectrum too. As you will see by watching the footage, the UFO vanishes in the visible spectrum. Please watch in the best possible quality format and full screen...