Good & Bad Ghost Hunting Equipment
Adventures in Ghost Hunting: Lame and Laudable
A while back, I put out a challenge to ghost investigators to come up with new ideas: new gadgets, protocols and theories to further our understanding of or gather better evidence for the ghost phenomenon. It's a tough challenge when we don't really know what we're dealing with for the most part. Although the inventors weren't responding to my challenge, following are two new ghost-hunting gadgets; one completely laughable (should we say fraudulent?) and one that's interesting and potentially useful to ghost investigators.
THE PARABOT
A guy by the name of Robert Bess from Richmond, Virginia, claims to have built a machine that can capture ghosts and poltergeists. He calls it the Parabot. It's a big glass-walled box on wheels, fitted with colored lights, spark generators and a few electronics of dubious purpose. The thing makes a lot of noise, and apparently Bess can open and close its doors by remote control. Does it capture ghosts? Uh... what do you think? This is one of the silliest things I've seen in this field in quite awhile, but it did get Bess the attention of The Travel Channel, which featured this nonsense on theirGhost Adventures Live cablecast last Halloween. Did he catch ghosts live on the air? Uh... what do you think? Bess further proved himself less than trustworthy on the same show when he was caught on camera throwing an EMF meter across the room and then exclaiming, "Whoa! What was that?!" We really don't need guys like this in paranormal investigation.
EVP FIELD PROCESSOR
On the other hand, we have the EVP Field Processor (EFP) developed by Larry Odien for the American Paranormal Research Association. It's not a huge breakthrough, but certainly could be of benefit to investigators hoping to capture EVP. The EFP is a modified digital audio recorder that provides a real-time visual display of the sounds recorded. So what? The advantage here is that although you still might not be able to hear the EVP voice at the time it is recorded, it might register on the visual display. So when you see an anomalous spike on the visual display when all is silent, you might have captured an EVP. Play it back and find out. This can corroborate evidence, especially when a video camera is focused on the display; then you have a visual recording of the spike when it occurs along with the audio recording. Nice job.
Digital Recorders vs. Analog Tape Recorders
To Buy Or Not To Buy a Digital Recorder – 7 Features to Consider
Analog tape recording devices have been around for decades and still play an important role in dictation and transcription.
In recent years, however, you’ve probably seen more digital recorders in the pockets and on the desks of everyone from students and office assistants to doctors, lawyers, and board chairmen.
Is it worth upgrading from analog microcassettes to digital smart cards? Will you be able to figure out how to use it? And will you be able to afford it?
7 features to consider when considering Digital vs. Analog Recorders
1. PORTABILITY. Technology has advanced to the point where digital recorders are as small and light, if not smaller and lighter, than microcassette recorders, so you’ll be able to take them anywhere you need them. By the way, these digital recorders are great gifts for people on the go.
2. RECORDING MEDIA . Digital recorders use either internal flash memory or smart cards, which can be inserted and ejected like cassettes, to record. Both options give you anywhere from dozens to hundreds of hours of recording time, even on the smallest digital devices. When you’ve run out of recording room, you can simply transfer the files to your computer and erase them from the recorder. If you’re using a recording device with smart cards, you can simply buy a new one, pop it in the recorder and go.
3. DURABILITY. Analog recorders are rugged and long-lasting. Contrary to what you might think, so are digital recorders. In fact, because they have no moving parts, they’re built to last for years with virtually no wear and tear. Same goes for the smart cards which many digital recorders employ. All the information is stored on chips in the smart card, so there’s nothing to rewind or fast-forward when you’re looking for a specific part of the recording. As a result, it’s virtually impossible (pun intended) for a smart card to wear out.
4. STORING AND SHARING RECORDINGS. Digital recorders connect directly to your computer – many of them don’t even require a USB cord – so you can transfer files to your hard drive quickly and easily. This makes it a snap to flexibily organize your files, and it also makes it much easier to send files to multiple users via email. Have a long meeting you want transcribed by more than one person at the same time? Simply transfer the recording from your digital recorder to your computer and send it off to all the transcribers simultaneously. If you want a hard copy, just burn the file/files to a CD.
5. EASE OF USE. Recording digitally makes it easier to find a specific part of your sound file. No more rewinding and fast-forwarding! If you want to hear something that was said half an hour or two hours or five hours into your meeting, you can access it in seconds. You can even extract the important parts of a long recording and make separate files for them. And it’s practically unheard of to mistakenly erase a sound file. Unlike an analog cassette, you can’t simply rewind a digital file and accidentally record over it – erasing it takes deliberate effort.
6. ENGINEERING. It’s nearly impossible to mess up a digital recording. Depending on your budget, you can purchase a recorder which will automatically set recording levels. Many digital recorders can also record only when sound is detected. That way, if you’re recording a seminar or meeting with a lot of long pauses, you won’t have a lot of “dead air” on your recording.
7. PRICE. Analog tape recorders still have a price advantage at the lower end of the market, but as you add bells and whistles, there’s a wide range of digital recorders available at competitive prices. The time has arrived when state-of-the-art digital recording technology is within the reach of everyone from students to executives.
Take a look at our selection of digital voice recorders and see which one is right for your needs and your budget! Or if you are a particular fan of Olympus, see our review of current Olympus recorders.
Electronic Voice Phenomena
EVP or Electronic Voice Phenomena. In the good old days people went to fortune tellers and mediums to talk to their dead loved ones. Today we use a different approach. What if instead of mediums and fortune tellers the dead could talk to us directly? Well they can with the use of recorders,digital and analog devices that record voices. Electronic voice phenomena - or EVP - is a mysterious event in which human-sounding voices from an unknown source are heard on recording tape, in radio station noise and other electronic media. Most often, EVPs have been captured on audiotape. The mysterious voices are not heard at the time of recording; it is only when the tape is played back that the voices are heard. Sometimes amplification and noise filtering is required to hear the voices.
Some EVP is more easily heard and understood than others. And they vary in gender (men and women), age (women and children), tone and emotion. They usually speak in single-words, phrases and short sentences. Sometimes they are just grunts, groans, growling and other vocal noises. EVP has been recorded speaking in various languages.
The quality of EVP also varies. Some are difficult to distinguish and are open to interpretation as to what they are saying. Some EVP, however, are quite clear and easy to understand. EVP often has an electronic or mechanical character to it; sometimes it is natural sounding. The quality of EVP is categorized by researchers:Class A: Easily understood by almost anyone with little or no dispute. These are also usually the loudest EVPs.Class B: Usually characterized by warping of the voice in certain syllables. Lower in volume or more distant sounding than Class A. Class B is the most common type of EVP.Class C: Characterized by excessive warping. They are the lowest in volume (often whispering) and are the hardest to understand.The most fascinating aspect of EVP is that the voices sometimes respond directly to the persons making the recording. The researchers will ask a question, for example, and the voice will answer or comment. Again, this response is not heard until later when the tape is played back.An EVP Session is done by turning on your recorder in an area of known activity and asking questions. If you know the name of the spirit who is said to be haunting the area you can ask questions of that spirit. When asking questions always allow a few seconds between each one to give the spirit time to answer.Hope this is helpful to some.
Some EVP is more easily heard and understood than others. And they vary in gender (men and women), age (women and children), tone and emotion. They usually speak in single-words, phrases and short sentences. Sometimes they are just grunts, groans, growling and other vocal noises. EVP has been recorded speaking in various languages.
The quality of EVP also varies. Some are difficult to distinguish and are open to interpretation as to what they are saying. Some EVP, however, are quite clear and easy to understand. EVP often has an electronic or mechanical character to it; sometimes it is natural sounding. The quality of EVP is categorized by researchers:Class A: Easily understood by almost anyone with little or no dispute. These are also usually the loudest EVPs.Class B: Usually characterized by warping of the voice in certain syllables. Lower in volume or more distant sounding than Class A. Class B is the most common type of EVP.Class C: Characterized by excessive warping. They are the lowest in volume (often whispering) and are the hardest to understand.The most fascinating aspect of EVP is that the voices sometimes respond directly to the persons making the recording. The researchers will ask a question, for example, and the voice will answer or comment. Again, this response is not heard until later when the tape is played back.An EVP Session is done by turning on your recorder in an area of known activity and asking questions. If you know the name of the spirit who is said to be haunting the area you can ask questions of that spirit. When asking questions always allow a few seconds between each one to give the spirit time to answer.Hope this is helpful to some.
Franks Box
Does Frank's Box Really Communicate with the Dead?
How one invention may help you communicate with spirits.
Frank Sumption is the original creator of the Ghost Box, otherwise known as the "Franks Box". He created the device as a means of communicating with higher level spirits such as Angles and spirit guides. But the device is being tested by paranormal investigators all around the world and is creating a buzz in the paranormal community.
Frank's box scans AM/FM frequencies in a continuous fashion,creating White Noise , which people believe spirit can use to communicate with.The box is said to be interactive because you can ask questions directly of a spirit and receive reply's from them while talking.
Frank Sumption made the box using radio,electronic.and computer components. He made the first box in 2002,after being prompted to do so from the spirit world. At the time he made less than 3 dozen,and eventually gave out a few of them to selective participants so that they could test them out for themselves to see if the boxes could be used to communicate with spirits from the other side.
Recently, Christopher Moon appeared on Paranormal State featured on A&E and used what he called "the telephone to the dead". Frank Sumption had given Mr. Moon one of the devices to test out,and since then Mr. Moon has begun charging clients who want to communicate with passed over loved ones and other spirits, using his telephone to the dead. Rumor has it that Frank Sumption does not agree with Mr. Moons practices of charging people while using his creation and that it was never intended for such use.
After word got out about the Frank's box, people began to do their own experiments and there are quite a few variations of the original device,including the Radio Shack Hack,which is made by altering an AM/FM radio by cutting the mute pin on the radio so it continuously scans the radio frequencies.
Those who have tested this method say they have gotten results comparable to the original Frank's Box. Until the devices popped up ,the most widely used means of communication with spirits has been through audio tape and digital recorders which can pick up voices of disembodied spirits. The newer methods may allow users to communicate in real time with spirits who have crossed over to the other side.
Thomas Edison said himself someone should create a device to communicate with the spirits. Nobody knows if he ever started work on such a device of his own or not. Whether you are a believer or not such ideas and theories can certainly raise the interest of people and get them to test such methods out for themselves.
Ghost Hunting Tips & Rules
Ghost Hunting Tips & Rules
- Never go ghost hunting alone.
- Always let someone know where you will be.
- Always carry id.
- If you feel uncomfortable, leave!
- Get permission before going onto private property or to be in a cemetery after hours.
- Reschedule your ghost hunt if it is going to snow, rain, or if it is foggy. Also check the pollen count. Moisture and pollen can cause anomalies in photos.
- If you have a large group break up into pairs or smaller groups.
- Carry walkie talkies or cell phones. You never know when you might need them.
- Don't use drugs or alcohol before or during an investigation or hunt.
- Don't smoke near where you will be investigating. Make a designated spot for smoking. You don't want to photograph smoke and think it is an ecto mist or spirit.
- When trying to record evps never whisper. Talk in a normal voice. You won't scare the ghosts if you talk. And you don't want to mistake a human whisper for a spirit.
- Always use new tapes in the recorder.
- Have extra batteries and make sure all equipment is fully charged.
- Wear a watch so you can note times of events.
- Wear clothing suited for the weather and always wear comfortable shoes.
- Don't wear jackets with strings. The strings could get in the way when taking photos and be mistaken for something paranormal, especially if you are shooting downward.
- Don't wear perfume or cologne while ghost hunting. If using an insect repellent make sure it is unscented. Some have noticed scents or smells when there is reported ghost activity. Perfumes may mask these scents.
- Tie back long hair. When a piece of hair gets in front of the camera lens it will look like a vortex.
- Remove camera straps or be aware where they are when taking a photo. Many times straps get in the picture and can be mistaken for a vortex, ecto, moving orb and ghosts.
- Look for things in the way like spiderwebs, wire, ropes, tree limbs. They can appear on photos as something paranormal when they are in close range of the camera lens.
- Always clean camera lenses. Lint, dust specks, smudges and fingerprints can look like ecto mist, orbs, and other ghostly anomalies.
- Be aware of the temperature when photographing outdoors or in an unheated building. Hold your breath while taking a photo and for several seconds afterward. Remember, if you can see it so can the camera.
- Always know where your fingers are when taking photos. A thumb or finger can appear to be a ghost when caught in front of the lens. It is a big let down to find out it's not paranormal after all.
- Research the location. If you are going ghost hunting after dark, you should check it out during daylight hours. Make note of any dangers such as holes, broken glass, loose boards etc.
- Be objective of your findings. Rule out any natural causes that may have caused anomalies such as insects, lights in the distance, spider webs, reflections.
http://paraghostal.blogspot.com/search/label/How%20to%27s
How Night Vision Works
by Jeff Tyson
60
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NVDs come in a variety of styles, including ones that can be mounted to cameras.
Photo courtesy of B.E. Meyers Company
Generations
NVDs have been around for more than 40 years. They are categorized by generation. Each substantial change in NVD technology establishes a new generation.
Generation 0 - The original night-vision system created by the United States Army and used in World War II and the Korean War, these NVDs use active infrared. This means that a projection unit, called an IR Illuminator, is attached to the NVD. The unit projects a beam of near-infrared light, similar to the beam of a normal flashlight. Invisible to the naked eye, this beam reflects off objects and bounces back to the lens of the NVD. These systems use an anode in conjunction with the cathode to accelerate the electrons. The problem with that approach is that the acceleration of the electrons distorts the image and greatly decreases the life of the tube. Another major problem with this technology in its original military use was that it was quickly duplicated by hostile nations, which allowed enemy soldiers to use their own NVDs to see the infrared beam projected by the device.
Generation 1 - The next generation of NVDs moved away from active infrared, using passive infraredinstead. Once dubbed Starlight by the U.S. Army, these NVDs use ambient light provided by the moon and stars to augment the normal amounts of reflected infrared in the environment. This means that they did not require a source of projected infrared light. This also means that they do not work very well on cloudy or moonless nights. Generation-1 NVDs use the same image-intensifier tube technology as Generation 0, with both cathode and anode, so image distortion and short tube life are still a problem.
Generation 2 - Major improvements in image-intensifier tubes resulted in Generation-2 NVDs. They offer improved resolution and performance over Generation-1 devices, and are considerably more reliable. The biggest gain in Generation 2 is the ability to see in extremely low light conditions, such as a moonless night. This increased sensitivity is due to the addition of the microchannel plate to the image-intensifier tube. Since the MCP actually increases the number of electrons instead of just accelerating the original ones, the images are significantly less distorted and brighter than earlier-generation NVDs.
Generation 3 - Generation 3 is currently used by the U.S. military. While there are no substantial changes in the underlying technology from Generation 2, these NVDs have even better resolution and sensitivity. This is because the photo cathode is made using gallium arsenide, which is very efficient at converting photons to electrons. Additionally, the MCP is coated with an ion barrier, which dramatically increases the life of the tube.
Generation 4 - What is generally known as Generation 4 or "filmless and gated" technology shows significant overall improvement in both low- and high-level light environments. The removal of the ion barrier from the MCP that was added in Generation 3 technology reduces the background noise and thereby enhances the signal to noise ratio. Removing the ion film actually allows more electrons to reach the amplification stage so that the images are significantly less distorted and brighter. The addition of an automatic gated power supply system allows the photocathode voltage to switch on and off rapidly, thereby enabling the NVD to respond to a fluctuation in lighting conditions in an instant. This capability is a critical advance in NVD systems, in that it allows the NVD user to quickly move from high-light to low-light (or from low-light to high-light) environments without any halting effects. For example, consider the ubiquitous movie scene where an agent using night vision goggles is “sightless” when someone turns on a light nearby. With the new, gated power feature, the change in lighting wouldn’t have the same impact; the improved NVD would respond immediately to the lighting change.
Many of the so-called "bargain" night-vision scopes use Generation-0 or Generation-1 technology, and may be disappointing if you expect the sensitivity of the devices used by professionals. Generation-2, Generation-3 and Generation 4 NVDs are typically expensive to purchase, but they will last if properly cared for. Also, any NVD can benefit from the use of an IR Illuminator in very dark areas where there is almost no ambient light to collect.
A cool thing to note is that every single image-intensifier tube is put through rigorous tests to see if it meets the requirements set forth by the military. Tubes that do are classified as MILSPEC. Tubes that fail to meet military requirements in even a single category are classified as COMSPEC.
EMF measurement
From Wikipedia, the free encyclopedia
Electric field probe FP2000 (range 100 kHz – 2500 MHz)
EMF measurements are measurements of ambient (surrounding) electromagnetic fields that are taken with particular sensors or probes, such as EMF meters. These probes can be generally considered as antennas although with different characteristics. In fact probes should not perturb the electromagnetic field and must prevent coupling and reflection as much possible in order to obtain a precise measure. EMF measurements are nowadays becoming important and widespread in different sectors to assess environmental and human exposure to non-ionizing radiation in many contexts. There are two main EMF measurements types:
broadband measurements performed using a broadband probe, that is a device which senses any signal across a wide range of frequencies and is usually made with three independent diode detectors;
frequency selective measurements in which the measurement system consists of a field antenna and a frequency selective receiver or spectrum analyzer allowing to monitor the frequency range of interest.
EMF probes may respond to fields only on one axis, or may be tri-axial, showing componets of the field in three directions at once. Amplified, active, probes can improve measurement precision and sensitivity but their active components may limit their speed of response.
Contents [hide]
1 Ideal isotropic measurements
2 Meters
2.1 Sensitivity
3 Active and passive sensors
4 Isotropic deviation
5 References
[edit]Ideal isotropic measurements
E-field projections on an orthogonal reference frame
Measurements of the EMF are obtained using an E-field sensor or H-field sensor which can be isotropic or mono-axial, active or passive. A mono-axial, omnidirectional probe is a device which senses the Electric (short dipole) or Magnetic field linearly polarized in a given direction.
Using a mono-axial probe implies the need for three measurements taken with the sensor axis set up along three mutually orthogonal directions, in a X, Y, Z configuration. As an example, it can be used a probe which senses the Electric field component parallel to the direction of its axis of symmetry. In these conditions, where E is the amplitude of incident electric field, and θ is the amplitude of the angle between sensor axis and direction of electric field E, the signal detected is proportional to |E|cos θ (right). This allows to obtain the correct total amplitude of the field in the form of
or, in case of the magnetic field
An isotropic(tri-axial) probe simplifies the measurement procedure because the total field value is determined with three measures taken without changing sensor position: this results from the geometry of the device which is made by three independent broadband sensing elements placed orthogonal to each other. In practice, each element’s output is measured in three consecutive time intervals supposing field components being time stationary .
Isotropic antenna AT3000 (passive probe, 20 MHz – 3000 MHz)
[edit]Meters
An EMF meter is a scientific instrument for measuring electromagnetic fields (abbreviated as EMF). Most meters measure the electromagnetic radiationflux density (DC fields) or the change in an electromagnetic field over time (AC fields), essentially the same as a radio antenna, but with quite different detection characteristics.
The two largest categories are single axis and tri-axis. Single axis meters are cheaper than a tri-axis meters, but take longer to complete a survey because the meter only measures one dimension of the field. Single axis instruments have to be tilted and turned on all three axes to obtain a full measurement. A tri-axis meter measures all three axes simultaneously, but these models tend to be more expensive.
Electromagnetic fields can be generated by AC or DC currents. An EMF meter can measure AC electromagnetic fields, which are usually emitted from man-made sources such as electrical wiring, while gaussmeters or magnetometers measure DC fields, which occur naturally in Earth's geomagnetic field and are emitted from other sources where direct current is present.
An example of an EMF meter.
[edit]Sensitivity
As most electromagnetic fields encountered in everyday situation are those generated by household or industrial appliances, the majority of EMF meters available are calibrated to measure 50 and 60 Hz alternating fields (the frequency of US and European mains electricity). There are other meters which can measure fields alternating at as low as 20 Hz, however these tend to be much more expensive and are only used for specific research purposes.
[edit]Active and passive sensors
Active sensors are sensing devices which contain active components; usually this solution allows for a more precise measurement with respect to passive components. In fact, a passive receiving antenna collects energy from the electromagnetic field being measured and makes it available at a RF cable connector. This signal then goes to the spectrum analyzer but the field characteristics can be someway modified by the presence of the cable, especially in near-field conditions.
On the other hand an effective solution is to transfer on an optical carrier, the electric (or magnetic) field component sensed with an active probe. The basic components of the system are a receiving electro-optical antenna which is able to transfer, on an optical carrier, the individual electric (or magnetic) field component picked up and to return it in the form of an electrical signal at the output port of an opto-electric converter.
The modulated optical carrier is transferred by means of a fiber-optic link to a converter which extracts the modulating signal and converts it back to an electrical signal. The electrical signal thus obtained can be then sent to a spectrum analyzer with a 50 Ω common RF cable.
[edit]Isotropic deviation
Short dipole radiation pattern
Isotropic deviation, in EMF measurements, is a parameter that describes the accuracy in measuring field intensities irrespective of the probe’s orientation. If the field is obtained by three measurements in an orthogonal X, Y, Z configuration in the form:
a sufficient condition for the expression to be true for every three orthogonal coordinates (X,Y,Z) is for the probe radiation patternto be as close as possible to ideal short dipole pattern, called sin θ:
,
where A is function of frequency. The difference between ideal dipole radiation pattern and real probe pattern is called isotropic deviation.
Full-spectrum photography
Full-spectrum photography is a subset of multispectral imaging, defined among photography enthusiasts as imaging with consumer cameras the full, broad spectrum of a film or camera sensor bandwidth. In practice, specialized broadband/full-spectrum film captures visible and near infrared light, commonly referred to as the "VNIR".[1]
Modified digital cameras can detect some ultraviolet, all of the visible and much of the near infrared spectrum, as most digital imaging sensors are sensitive from about 350 nm to 1000 nm. An off-the-shelf digital camera contains an infrared hot mirror filter that blocks most of the infrared and a bit of the ultraviolet that would otherwise be detected by the sensor, narrowing the accepted range from about 400 nm to 700 nm.[2] Replacing a hot mirror or infrared blocking filter with an infrared pass or a wide spectrally transmitting filter allows the camera to detect the wider spectrum light at greater sensitivity. Without the hot-mirror, the red, green and blue (or cyan, yellow and magenta) elements of the color filter array placed over the sensor elements pass varying amounts of ultraviolet and infrared which may be recorded in any of the red, green or blue channels depending on the particular sensor in use and on the dyes used in the Bayer filter. A converted full-spectrum camera can be used for ultraviolet photography or infrared photography with the appropriate filters.
Uses of full-spectrum photography include fine art photography, geology, forensics & law enforcement, and even some claimed use inghost hunting.
Full-spectrum photography has its roots in spectral imaging, both multispectral and hyperspectral imaging, which began as early as the late 1950s and early 1960s as means for geological and military remote sensing. Wideband panchromatic film has been available in various forms since the 1920s, when some UV and IR sensitivity remained in commercially available emulsions. The earliest color films sometimes included wider band color than recent commercial photographic emulsions, and can be recognized by the more reddish and or limited color tones of early color prints (not to be confused with print fading).
In the late 1990s enthusiastic photographers began shooting infrared with digital cameras, necessitating either long exposures or the removal of the internal hot mirror. Most replaced the hot mirror with an infrared pass filter of the same optical thickness (to retain focus) and pass only infrared light to achieve results seen with infrared B&W film. Around 2000, electro-optical engineer David Twede, already engaged in VNIR and infrared spectral remote sensing, ventured into Full-spectrum photography art, using a modified digital camera to explore broader spectral imaging and developing art around it. Around 2003, forensics photographers using engineered cameras for specific purposes began modifying off-the-shelf digital cameras to acquire less expensive tools. Full-spectrum photography is used by enthusiasts of ghost hunting, though no claims of actually photographing psychic phenomenon with Full-spectrum or infrared photography have been substantiated.
Today, there are a few places that will modify digital cameras to pass broad, full-spectrum light for full spectral imaging. A few DSLR cameras such as the Fujifilm FinePix IS Pro are purpose-designed for full spectrum use and respond from approximately 1000 nm (IR) to 380 nm (UV).
Full-spectrum photography has its roots in spectral imaging, both multispectral and hyperspectral imaging, which began as early as the late 1950s and early 1960s as means for geological and military remote sensing. Wideband panchromatic film has been available in various forms since the 1920s, when some UV and IR sensitivity remained in commercially available emulsions. The earliest color films sometimes included wider band color than recent commercial photographic emulsions, and can be recognized by the more reddish and or limited color tones of early color prints (not to be confused with print fading).
In the late 1990s enthusiastic photographers began shooting infrared with digital cameras, necessitating either long exposures or the removal of the internal hot mirror. Most replaced the hot mirror with an infrared pass filter of the same optical thickness (to retain focus) and pass only infrared light to achieve results seen with infrared B&W film. Around 2000, electro-optical engineer David Twede, already engaged in VNIR and infrared spectral remote sensing, ventured into Full-spectrum photography art, using a modified digital camera to explore broader spectral imaging and developing art around it. Around 2003, forensics photographers using engineered cameras for specific purposes began modifying off-the-shelf digital cameras to acquire less expensive tools. Full-spectrum photography is used by enthusiasts of ghost hunting, though no claims of actually photographing psychic phenomenon with Full-spectrum or infrared photography have been substantiated.
Today, there are a few places that will modify digital cameras to pass broad, full-spectrum light for full spectral imaging. A few DSLR cameras such as the Fujifilm FinePix IS Pro are purpose-designed for full spectrum use and respond from approximately 1000 nm (IR) to 380 nm (UV).
Full-spectrum photography has its roots in spectral imaging, both multispectral and hyperspectral imaging, which began as early as the late 1950s and early 1960s as means for geological and military remote sensing. Wideband panchromatic film has been available in various forms since the 1920s, when some UV and IR sensitivity remained in commercially available emulsions. The earliest color films sometimes included wider band color than recent commercial photographic emulsions, and can be recognized by the more reddish and or limited color tones of early color prints (not to be confused with print fading).
In the late 1990s enthusiastic photographers began shooting infrared with digital cameras, necessitating either long exposures or the removal of the internal hot mirror. Most replaced the hot mirror with an infrared pass filter of the same optical thickness (to retain focus) and pass only infrared light to achieve results seen with infrared B&W film. Around 2000, electro-optical engineer David Twede, already engaged in VNIR and infrared spectral remote sensing, ventured into Full-spectrum photography art, using a modified digital camera to explore broader spectral imaging and developing art around it. Around 2003, forensics photographers using engineered cameras for specific purposes began modifying off-the-shelf digital cameras to acquire less expensive tools. Full-spectrum photography is used by enthusiasts of ghost hunting, though no claims of actually photographing psychic phenomenon with Full-spectrum or infrared photography have been substantiated.
Today, there are a few places that will modify digital cameras to pass broad, full-spectrum light for full spectral imaging. A few DSLR cameras such as the Fujifilm FinePix IS Pro are purpose-designed for full spectrum use and respond from approximately 1000 nm (IR) to 380 nm (UV).
Basics
Digital sensors and photographic films can be made to record non-visible ultraviolet (UV) and infrared (IR) radiation. In each case, they generally require special equipment: converted digital cameras, specific filters, highly transmitting lenses, etc. For example, most photographic lenses are made of glass and will filter out most ultraviolet light. Instead, expensive lenses made of quartz must be used. Infrared films may be shot in standard cameras using an infrared pass filters, although focus must compensate for the infrared focal point.
A converted digital camera usually requires that the infrared hot mirror be removed and replaced by a wideband, spectrally flat glass of the same optical path length.[3] Typical glass types used include Schott WG-280[4] and BK-7,[5] which transmit as much as 90% from around 300 nm to past 1000 nm. Removing the hot mirror is tedious and may require special tools and clean rooms.[6]
Once the camera is sensitive to the full-spectrum, external filters can be used to selectively filter portions of the UV, visible and infrared to achieve various effects.[7] For example, a standard red #25a can be used to include red light and infrared light together, yielding particularly strong two-toned color images of a reddish nature except where the infrared is high and shows as cyan.[8] Another example, using UV/IR filters such as the 18A or U-330 yield a two or three toned image in which blues and yellows dominate.[9] Less common filters have been claimed to give a variety of color effects ranging from diverse pastel foliage and deep blue skies to surrealistic effects of the sky and ground,[10] though digital image processing is likely required to achieve the full effects. One issue with Full-spectrum photography in either film or digital photogrqaphy is the chromatic aberration produced by the wideband information. That is, different spectra, including the ultraviolet and infrared, will focus at different focal points, yielding blurry images and color edge effects, depending on the focal length used. There are specialized lenses such as the Nikon 105mm f4.5 UV-Nikkor which are designed to eliminate this chromatic aberration.
It is important to note that while the converted camera sensor is capable of recording in both the ultraviolet and infrared region, when mixed light hits the sensor it will be the longer infrared waves that will predominate in the recording. Little or no shortwave ultraviolet light may be recorded unless selective filtering is applied to cut some or all of the infrared light. The longwave infrared light may also wash out a considerable amount of the visible light in the blue and green areas in a full spectrum photograph. Similarly if infrared light is entirely blocked, the visible light can overwhelm the recording of the ultraviolet light. So there is no truly full-spectrum photograph that can be made.
Full-spectrum photography achieves various effects and surrealistic colors from the interaction of reflectivity (UV, visible, IR) of nature and man made materials and the specific spectral transmission of the red, green and blue filters on the camera.[10] The addition of external filters will reduce and emphasize different interactions, yielding different effects.[7]
[edit]Applications
[edit]Art
Full-spectrum Photography is being used for art photography and can yield colors similar to visible color film, but with a brightness and tonality of infrared photographs. Most full-spectrum art is of landscapes. A movement is also building for artistic human photography with Full-spectrum photography, that captures a real person interacting with a surreal landscape. Full-spectrum photography art is displayed at galleries in Colorado and Florida.
[edit]Science hobbyists
Hyperspectral and most multispectral cameras are expensive and difficult to operate, requiring a computer acquisition and laborious post-processing. Modified digital cameras with the proper filtering avail some limited spectral sensing for geology/mineralogy, agriculture and oceanographic purposes. Most consumer cameras retain the red, green and blue micro-filters, thus limiting their usefulness in scientific imaging.
[edit]Forensics
Forensics imaging often uses Full-spectrum cameras to emphasize non-visible materials which have more diverse reflectivities in the ultraviolet and infrared. Applications include non-visible inks (uv & ir), disturbed soil (uv & ir), gunshot residue (ir), body fluids (uv), fibers, etc. Analogous to forensics, Full-spectrum cameras are being explored to enhance photographic recordings of archeological findings.
K2 mod.
Lazer Grid
No night vision,no problem
IR lights
Camera tricks and tips
http://paraghostal.blogspot.com/search/label/How%20to%27s
How Night Vision Works
by Jeff Tyson
60
Page
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NVDs come in a variety of styles, including ones that can be mounted to cameras.
Photo courtesy of B.E. Meyers Company
Generations
NVDs have been around for more than 40 years. They are categorized by generation. Each substantial change in NVD technology establishes a new generation.
Generation 0 - The original night-vision system created by the United States Army and used in World War II and the Korean War, these NVDs use active infrared. This means that a projection unit, called an IR Illuminator, is attached to the NVD. The unit projects a beam of near-infrared light, similar to the beam of a normal flashlight. Invisible to the naked eye, this beam reflects off objects and bounces back to the lens of the NVD. These systems use an anode in conjunction with the cathode to accelerate the electrons. The problem with that approach is that the acceleration of the electrons distorts the image and greatly decreases the life of the tube. Another major problem with this technology in its original military use was that it was quickly duplicated by hostile nations, which allowed enemy soldiers to use their own NVDs to see the infrared beam projected by the device.
Generation 1 - The next generation of NVDs moved away from active infrared, using passive infraredinstead. Once dubbed Starlight by the U.S. Army, these NVDs use ambient light provided by the moon and stars to augment the normal amounts of reflected infrared in the environment. This means that they did not require a source of projected infrared light. This also means that they do not work very well on cloudy or moonless nights. Generation-1 NVDs use the same image-intensifier tube technology as Generation 0, with both cathode and anode, so image distortion and short tube life are still a problem.
Generation 2 - Major improvements in image-intensifier tubes resulted in Generation-2 NVDs. They offer improved resolution and performance over Generation-1 devices, and are considerably more reliable. The biggest gain in Generation 2 is the ability to see in extremely low light conditions, such as a moonless night. This increased sensitivity is due to the addition of the microchannel plate to the image-intensifier tube. Since the MCP actually increases the number of electrons instead of just accelerating the original ones, the images are significantly less distorted and brighter than earlier-generation NVDs.
Generation 3 - Generation 3 is currently used by the U.S. military. While there are no substantial changes in the underlying technology from Generation 2, these NVDs have even better resolution and sensitivity. This is because the photo cathode is made using gallium arsenide, which is very efficient at converting photons to electrons. Additionally, the MCP is coated with an ion barrier, which dramatically increases the life of the tube.
Generation 4 - What is generally known as Generation 4 or "filmless and gated" technology shows significant overall improvement in both low- and high-level light environments. The removal of the ion barrier from the MCP that was added in Generation 3 technology reduces the background noise and thereby enhances the signal to noise ratio. Removing the ion film actually allows more electrons to reach the amplification stage so that the images are significantly less distorted and brighter. The addition of an automatic gated power supply system allows the photocathode voltage to switch on and off rapidly, thereby enabling the NVD to respond to a fluctuation in lighting conditions in an instant. This capability is a critical advance in NVD systems, in that it allows the NVD user to quickly move from high-light to low-light (or from low-light to high-light) environments without any halting effects. For example, consider the ubiquitous movie scene where an agent using night vision goggles is “sightless” when someone turns on a light nearby. With the new, gated power feature, the change in lighting wouldn’t have the same impact; the improved NVD would respond immediately to the lighting change.
Many of the so-called "bargain" night-vision scopes use Generation-0 or Generation-1 technology, and may be disappointing if you expect the sensitivity of the devices used by professionals. Generation-2, Generation-3 and Generation 4 NVDs are typically expensive to purchase, but they will last if properly cared for. Also, any NVD can benefit from the use of an IR Illuminator in very dark areas where there is almost no ambient light to collect.
A cool thing to note is that every single image-intensifier tube is put through rigorous tests to see if it meets the requirements set forth by the military. Tubes that do are classified as MILSPEC. Tubes that fail to meet military requirements in even a single category are classified as COMSPEC.
EMF measurement
From Wikipedia, the free encyclopedia
Electric field probe FP2000 (range 100 kHz – 2500 MHz)EMF measurements are measurements of ambient (surrounding) electromagnetic fields that are taken with particular sensors or probes, such as EMF meters. These probes can be generally considered as antennas although with different characteristics. In fact probes should not perturb the electromagnetic field and must prevent coupling and reflection as much possible in order to obtain a precise measure. EMF measurements are nowadays becoming important and widespread in different sectors to assess environmental and human exposure to non-ionizing radiation in many contexts. There are two main EMF measurements types:
broadband measurements performed using a broadband probe, that is a device which senses any signal across a wide range of frequencies and is usually made with three independent diode detectors;
frequency selective measurements in which the measurement system consists of a field antenna and a frequency selective receiver or spectrum analyzer allowing to monitor the frequency range of interest.
EMF probes may respond to fields only on one axis, or may be tri-axial, showing componets of the field in three directions at once. Amplified, active, probes can improve measurement precision and sensitivity but their active components may limit their speed of response.
Contents [hide]
1 Ideal isotropic measurements
2 Meters
2.1 Sensitivity
3 Active and passive sensors
4 Isotropic deviation
5 References
[edit]Ideal isotropic measurements
E-field projections on an orthogonal reference frameMeasurements of the EMF are obtained using an E-field sensor or H-field sensor which can be isotropic or mono-axial, active or passive. A mono-axial, omnidirectional probe is a device which senses the Electric (short dipole) or Magnetic field linearly polarized in a given direction.
Using a mono-axial probe implies the need for three measurements taken with the sensor axis set up along three mutually orthogonal directions, in a X, Y, Z configuration. As an example, it can be used a probe which senses the Electric field component parallel to the direction of its axis of symmetry. In these conditions, where E is the amplitude of incident electric field, and θ is the amplitude of the angle between sensor axis and direction of electric field E, the signal detected is proportional to |E|cos θ (right). This allows to obtain the correct total amplitude of the field in the form of
or, in case of the magnetic field
An isotropic(tri-axial) probe simplifies the measurement procedure because the total field value is determined with three measures taken without changing sensor position: this results from the geometry of the device which is made by three independent broadband sensing elements placed orthogonal to each other. In practice, each element’s output is measured in three consecutive time intervals supposing field components being time stationary .
Isotropic antenna AT3000 (passive probe, 20 MHz – 3000 MHz)[edit]Meters
An EMF meter is a scientific instrument for measuring electromagnetic fields (abbreviated as EMF). Most meters measure the electromagnetic radiationflux density (DC fields) or the change in an electromagnetic field over time (AC fields), essentially the same as a radio antenna, but with quite different detection characteristics.
The two largest categories are single axis and tri-axis. Single axis meters are cheaper than a tri-axis meters, but take longer to complete a survey because the meter only measures one dimension of the field. Single axis instruments have to be tilted and turned on all three axes to obtain a full measurement. A tri-axis meter measures all three axes simultaneously, but these models tend to be more expensive.
Electromagnetic fields can be generated by AC or DC currents. An EMF meter can measure AC electromagnetic fields, which are usually emitted from man-made sources such as electrical wiring, while gaussmeters or magnetometers measure DC fields, which occur naturally in Earth's geomagnetic field and are emitted from other sources where direct current is present.
An example of an EMF meter.[edit]Sensitivity
As most electromagnetic fields encountered in everyday situation are those generated by household or industrial appliances, the majority of EMF meters available are calibrated to measure 50 and 60 Hz alternating fields (the frequency of US and European mains electricity). There are other meters which can measure fields alternating at as low as 20 Hz, however these tend to be much more expensive and are only used for specific research purposes.
[edit]Active and passive sensors
Active sensors are sensing devices which contain active components; usually this solution allows for a more precise measurement with respect to passive components. In fact, a passive receiving antenna collects energy from the electromagnetic field being measured and makes it available at a RF cable connector. This signal then goes to the spectrum analyzer but the field characteristics can be someway modified by the presence of the cable, especially in near-field conditions.
On the other hand an effective solution is to transfer on an optical carrier, the electric (or magnetic) field component sensed with an active probe. The basic components of the system are a receiving electro-optical antenna which is able to transfer, on an optical carrier, the individual electric (or magnetic) field component picked up and to return it in the form of an electrical signal at the output port of an opto-electric converter.
The modulated optical carrier is transferred by means of a fiber-optic link to a converter which extracts the modulating signal and converts it back to an electrical signal. The electrical signal thus obtained can be then sent to a spectrum analyzer with a 50 Ω common RF cable.
[edit]Isotropic deviation
Short dipole radiation patternIsotropic deviation, in EMF measurements, is a parameter that describes the accuracy in measuring field intensities irrespective of the probe’s orientation. If the field is obtained by three measurements in an orthogonal X, Y, Z configuration in the form:
a sufficient condition for the expression to be true for every three orthogonal coordinates (X,Y,Z) is for the probe radiation patternto be as close as possible to ideal short dipole pattern, called sin θ:
,where A is function of frequency. The difference between ideal dipole radiation pattern and real probe pattern is called isotropic deviation.
Full-spectrum photography
Full-spectrum photography is a subset of multispectral imaging, defined among photography enthusiasts as imaging with consumer cameras the full, broad spectrum of a film or camera sensor bandwidth. In practice, specialized broadband/full-spectrum film captures visible and near infrared light, commonly referred to as the "VNIR".[1]
Modified digital cameras can detect some ultraviolet, all of the visible and much of the near infrared spectrum, as most digital imaging sensors are sensitive from about 350 nm to 1000 nm. An off-the-shelf digital camera contains an infrared hot mirror filter that blocks most of the infrared and a bit of the ultraviolet that would otherwise be detected by the sensor, narrowing the accepted range from about 400 nm to 700 nm.[2] Replacing a hot mirror or infrared blocking filter with an infrared pass or a wide spectrally transmitting filter allows the camera to detect the wider spectrum light at greater sensitivity. Without the hot-mirror, the red, green and blue (or cyan, yellow and magenta) elements of the color filter array placed over the sensor elements pass varying amounts of ultraviolet and infrared which may be recorded in any of the red, green or blue channels depending on the particular sensor in use and on the dyes used in the Bayer filter. A converted full-spectrum camera can be used for ultraviolet photography or infrared photography with the appropriate filters.
Uses of full-spectrum photography include fine art photography, geology, forensics & law enforcement, and even some claimed use inghost hunting.
Full-spectrum photography has its roots in spectral imaging, both multispectral and hyperspectral imaging, which began as early as the late 1950s and early 1960s as means for geological and military remote sensing. Wideband panchromatic film has been available in various forms since the 1920s, when some UV and IR sensitivity remained in commercially available emulsions. The earliest color films sometimes included wider band color than recent commercial photographic emulsions, and can be recognized by the more reddish and or limited color tones of early color prints (not to be confused with print fading).
In the late 1990s enthusiastic photographers began shooting infrared with digital cameras, necessitating either long exposures or the removal of the internal hot mirror. Most replaced the hot mirror with an infrared pass filter of the same optical thickness (to retain focus) and pass only infrared light to achieve results seen with infrared B&W film. Around 2000, electro-optical engineer David Twede, already engaged in VNIR and infrared spectral remote sensing, ventured into Full-spectrum photography art, using a modified digital camera to explore broader spectral imaging and developing art around it. Around 2003, forensics photographers using engineered cameras for specific purposes began modifying off-the-shelf digital cameras to acquire less expensive tools. Full-spectrum photography is used by enthusiasts of ghost hunting, though no claims of actually photographing psychic phenomenon with Full-spectrum or infrared photography have been substantiated.
Today, there are a few places that will modify digital cameras to pass broad, full-spectrum light for full spectral imaging. A few DSLR cameras such as the Fujifilm FinePix IS Pro are purpose-designed for full spectrum use and respond from approximately 1000 nm (IR) to 380 nm (UV).
Full-spectrum photography has its roots in spectral imaging, both multispectral and hyperspectral imaging, which began as early as the late 1950s and early 1960s as means for geological and military remote sensing. Wideband panchromatic film has been available in various forms since the 1920s, when some UV and IR sensitivity remained in commercially available emulsions. The earliest color films sometimes included wider band color than recent commercial photographic emulsions, and can be recognized by the more reddish and or limited color tones of early color prints (not to be confused with print fading).
In the late 1990s enthusiastic photographers began shooting infrared with digital cameras, necessitating either long exposures or the removal of the internal hot mirror. Most replaced the hot mirror with an infrared pass filter of the same optical thickness (to retain focus) and pass only infrared light to achieve results seen with infrared B&W film. Around 2000, electro-optical engineer David Twede, already engaged in VNIR and infrared spectral remote sensing, ventured into Full-spectrum photography art, using a modified digital camera to explore broader spectral imaging and developing art around it. Around 2003, forensics photographers using engineered cameras for specific purposes began modifying off-the-shelf digital cameras to acquire less expensive tools. Full-spectrum photography is used by enthusiasts of ghost hunting, though no claims of actually photographing psychic phenomenon with Full-spectrum or infrared photography have been substantiated.
Today, there are a few places that will modify digital cameras to pass broad, full-spectrum light for full spectral imaging. A few DSLR cameras such as the Fujifilm FinePix IS Pro are purpose-designed for full spectrum use and respond from approximately 1000 nm (IR) to 380 nm (UV).
Full-spectrum photography has its roots in spectral imaging, both multispectral and hyperspectral imaging, which began as early as the late 1950s and early 1960s as means for geological and military remote sensing. Wideband panchromatic film has been available in various forms since the 1920s, when some UV and IR sensitivity remained in commercially available emulsions. The earliest color films sometimes included wider band color than recent commercial photographic emulsions, and can be recognized by the more reddish and or limited color tones of early color prints (not to be confused with print fading).
In the late 1990s enthusiastic photographers began shooting infrared with digital cameras, necessitating either long exposures or the removal of the internal hot mirror. Most replaced the hot mirror with an infrared pass filter of the same optical thickness (to retain focus) and pass only infrared light to achieve results seen with infrared B&W film. Around 2000, electro-optical engineer David Twede, already engaged in VNIR and infrared spectral remote sensing, ventured into Full-spectrum photography art, using a modified digital camera to explore broader spectral imaging and developing art around it. Around 2003, forensics photographers using engineered cameras for specific purposes began modifying off-the-shelf digital cameras to acquire less expensive tools. Full-spectrum photography is used by enthusiasts of ghost hunting, though no claims of actually photographing psychic phenomenon with Full-spectrum or infrared photography have been substantiated.
Today, there are a few places that will modify digital cameras to pass broad, full-spectrum light for full spectral imaging. A few DSLR cameras such as the Fujifilm FinePix IS Pro are purpose-designed for full spectrum use and respond from approximately 1000 nm (IR) to 380 nm (UV).
Basics
Digital sensors and photographic films can be made to record non-visible ultraviolet (UV) and infrared (IR) radiation. In each case, they generally require special equipment: converted digital cameras, specific filters, highly transmitting lenses, etc. For example, most photographic lenses are made of glass and will filter out most ultraviolet light. Instead, expensive lenses made of quartz must be used. Infrared films may be shot in standard cameras using an infrared pass filters, although focus must compensate for the infrared focal point.
A converted digital camera usually requires that the infrared hot mirror be removed and replaced by a wideband, spectrally flat glass of the same optical path length.[3] Typical glass types used include Schott WG-280[4] and BK-7,[5] which transmit as much as 90% from around 300 nm to past 1000 nm. Removing the hot mirror is tedious and may require special tools and clean rooms.[6]
Once the camera is sensitive to the full-spectrum, external filters can be used to selectively filter portions of the UV, visible and infrared to achieve various effects.[7] For example, a standard red #25a can be used to include red light and infrared light together, yielding particularly strong two-toned color images of a reddish nature except where the infrared is high and shows as cyan.[8] Another example, using UV/IR filters such as the 18A or U-330 yield a two or three toned image in which blues and yellows dominate.[9] Less common filters have been claimed to give a variety of color effects ranging from diverse pastel foliage and deep blue skies to surrealistic effects of the sky and ground,[10] though digital image processing is likely required to achieve the full effects. One issue with Full-spectrum photography in either film or digital photogrqaphy is the chromatic aberration produced by the wideband information. That is, different spectra, including the ultraviolet and infrared, will focus at different focal points, yielding blurry images and color edge effects, depending on the focal length used. There are specialized lenses such as the Nikon 105mm f4.5 UV-Nikkor which are designed to eliminate this chromatic aberration.
It is important to note that while the converted camera sensor is capable of recording in both the ultraviolet and infrared region, when mixed light hits the sensor it will be the longer infrared waves that will predominate in the recording. Little or no shortwave ultraviolet light may be recorded unless selective filtering is applied to cut some or all of the infrared light. The longwave infrared light may also wash out a considerable amount of the visible light in the blue and green areas in a full spectrum photograph. Similarly if infrared light is entirely blocked, the visible light can overwhelm the recording of the ultraviolet light. So there is no truly full-spectrum photograph that can be made.
Full-spectrum photography achieves various effects and surrealistic colors from the interaction of reflectivity (UV, visible, IR) of nature and man made materials and the specific spectral transmission of the red, green and blue filters on the camera.[10] The addition of external filters will reduce and emphasize different interactions, yielding different effects.[7]
[edit]Applications
[edit]Art
Full-spectrum Photography is being used for art photography and can yield colors similar to visible color film, but with a brightness and tonality of infrared photographs. Most full-spectrum art is of landscapes. A movement is also building for artistic human photography with Full-spectrum photography, that captures a real person interacting with a surreal landscape. Full-spectrum photography art is displayed at galleries in Colorado and Florida.
[edit]Science hobbyists
Hyperspectral and most multispectral cameras are expensive and difficult to operate, requiring a computer acquisition and laborious post-processing. Modified digital cameras with the proper filtering avail some limited spectral sensing for geology/mineralogy, agriculture and oceanographic purposes. Most consumer cameras retain the red, green and blue micro-filters, thus limiting their usefulness in scientific imaging.
[edit]Forensics
Forensics imaging often uses Full-spectrum cameras to emphasize non-visible materials which have more diverse reflectivities in the ultraviolet and infrared. Applications include non-visible inks (uv & ir), disturbed soil (uv & ir), gunshot residue (ir), body fluids (uv), fibers, etc. Analogous to forensics, Full-spectrum cameras are being explored to enhance photographic recordings of archeological findings.
K2 mod.
Lazer Grid
No night vision,no problem
IR lights
Camera tricks and tips
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