Andy

Yep, great article. I think it would be great also if it was put in the mag as well.

It answered some questions I was wondering about with IR cameras.

Funny that you should mention the magazine. Andy has already consented to letting us run it!

Thanks Andy!

It answered some questions I was wondering about with IR cameras.

Ty Nowhammies, nice to be here!

Hey cool, you found it!

Good to see ya here, and if you get the chance, listen to some of the podcasts. Great work and interviews.

-Andy

Welcome to PUG, AmyLynn. /biggrin.png' class='bbc_emoticon' alt=':blink:' />

Ty Nowhammies, nice to be here!

Hi Andy,

Thanks for posting that article. It actually came at a time that was perfect for us as we are looking into that exact same field of photography.

Welcome to PUG, AmyLynn. /biggrin.png' class='bbc_emoticon' alt=':P' />

Thanks for posting that article. It actually came at a time that was perfect for us as we are looking into that exact same field of photography.

The following is an article I wrote for my group. Since finding this forum and enjoying the input of like-minded researchers, I decided to post it here in case anyone would like to experiment with this exciting form of photography...

Thanks,

Andy

Primer for Introductory Infrared Photography and Paranormal Applications

By Andrew Selfridge

Ghosts and spirits seem to occupy an unseen world that is all around us, interacting with our own at their leisure. What if we were able to see into that unseen world, even if only just a small portion? Would it reveal answers to these mysterious phenomenon or would it merely eliminate yet another small portion of the electromagnetic spectrum as a candidate for spirit observation.

Being able to see in other spectrums of light has often been thought to give the observer an edge when dealing with visually documenting paranormal or supposed paranormal phenomena. One popular area for such study is infrared photography and video. Infrared (IR) refers to the spectrum of light wavelength located between 700 and 1400 nanometers (this figure fluctuates depending on source but that is the core range of the near-infrared). Actually, wavelengths in this range, although commonly referred to as infrared in the industry and where applied to paranormal research, is actually known as the near-infrared (NIR). In the context of paranormal applications, these terms tend to be used interchangeably, and although it is a bit of a misnomer, I will refer to the near infrared spectrum as IR or infrared for the duration of this article.

What is so special about this spectrum of light? Aside from the fact that we can't see it with our naked eyes (actually, dark-adapted eyes can detect near IR at the lower end of the spectrum) it is often thought that spirits can use this spectrum of light to manifest. Perhaps this mentality was borne from the famous infrared photo of "John" the supposed playful spirit that supposedly haunted the Toys-R-Us store in Sunnyvale Ca. in the late seventies. The case received a lot of publicity and controversy, but one thing that came from the case was a grainy, blurry black and white infrared photo showing was people described as the ghost of "John" leaning against an aisle rack. Witnesses reported that there was not anyone standing in the spot where the IR photo showed a person leaning against the rack. Another popular infrared photo was taken at the infamous Bachelor's Grove cemetery in Midlothian IL. The photo, a black and white IR shot, depicts a woman sitting on a bench in a white, flowing gown. The picture was taken during the daylight and witnesses again reported no one present in the shot while it was taken. This shot is commonly referred to as the "Madonna of Bachelor's Grove".

The popularity of the Niteshot™ feature on Sony branded cameras is also a testament to IR popularity in the paranormal field. With this technology becoming cheaper and easier to put in the hands of the average consumer around 1998, total dark infrared videos became a staple in many paranormal investigations. IR video served two purposes for the investigator. It allowed for the complete illumination of total darkness (0 lux) environments while also allowing the investigator to see any infrared video anomalies that might be present during the video. This was an extreme help to investigators everywhere, because the clarity afforded by this system was far better than night vision scopes using image intensifier technology. Prior to these Sony systems, if an investigator wished to film in total darkness, he or she would have to adapt a night-vision scope to their video equipment. The problem with this is that most nightvision scopes that are within the price range of the average investigator were referred to as "generation 1" devices. Generation 1 night vision scopes used a vacuum tube image intensifier to amplify light. This optic system resulted in a very strong fish eye effect, with distortion and chromatic aberration at the outside edge of the field of view. This also resulted in clear, distortion-free viewing only in the center 30 percent of the picture. This is why the Sony systems were welcomed with open arms from investigators everywhere.

There are limitations to the Sony Niteshot™ systems that need to be taken into consideration. Despite the fact that their picture quality was far superior to the night vision scope method, their sensitivity to total darkness without some form of infrared illumination was abysmal. These systems required ambient light, in the form of infrared illuminators, to function in 0 lux. Sony addressed this shortcoming with the SuperNiteshot™ feature where the image was brightened by extended exposure. The problem with using this feature in any type of video is that fast moving objects created ghosting artifacts, and usually identifiably benign objects such as bugs or dust took on a Spielberg-like poltergeist visual effect. Sony also introduced the Niteshot™ feature into several models of digital point-and-shoot cameras, allowing for infrared photography. These can also be used for daylight IR photography, but more on this later.

In the past, if you wished to photograph the IR spectrum, it usually meant that you needed a single-lens reflex (SLR) camera and special film. Prior to the advent of digital CCD and CMOS sensors and digital cameras in general, advanced photography required the use of an SLR camera so that exposure times and aperture could be controlled manually. Even after digital photography took off, most consumer based systems were point-and-shoot with limited control over shot variables. This meant that if you were interested in IR photography, you still had to use the SLR camera and IR film. Using infrared film was especially cumbersome due to special handling instructions. Infrared film needed to be kept refrigerated before loading. Loading and handling of the film was to be done in darkness, and developing as well as initial purchase were slightly more expensive than regular film. These factors made using IR film a hassle, and discouraged many folks from trying to use it.

Fast forward a few years and you come to a time where digital photography has revolutionized the way people photographically document paranormal research. One unexpected side-effect of the digital revolution was that the CCD and CMOS image sensors were highly sensitive to the IR range (and ultraviolet as well). Manufacturers noted that this would saturate their images, so they placed a piece of glass coated with a special optic film known as an IR cut filter. Basically it allowed only visible light wavelengths to pass through to the image sensor. This cut filter would stabilize color levels in visible light, but basically makes infrared photography all but impossible. In Sony Niteshot™ products, this filter (sometimes referred to as a hot mirror) is removed from the image sensor and the color values are dropped in favor of that green hue (green is used in most night vision applications because the human eye can distinguish more shades of green in low light than any other color). Early adopters of Sony products also found that with longer exposures and a good infrared filter, certain materials of clothing became transparent in infrared. Afraid of what that would mean for Sony's liability when these cameras were used improperly, the company restricted the camera's aperture and exposure settings when in Niteshot™ mode. With the new camera settings in effect, Niteshot™ mode restricted the user to only taking pictures at night.

Digital camera manufacturers have done a fine job of making sure that their products are used in visible light applications only. Since we know that the image chips are capable of infrared and uv sensitivity and that they are only being blocked by the use of a mechanical cut filter, modifying these cameras for shooting in the infrared. If you removed the cut filter and replaced it with a piece of glass (so as not to change the focus of the optic system) and used a commercially available filter, you could effectively shoot in the infrared spectrum without the use of special films. There are services available for those folks that aren't technically gifted with taking their camera apart and modifying it. They will modify it for a charge (usually pretty expensive) and you can shoot IR at your leisure. It should also be noted that if you modify a digital camera for use with IR photography, that it is a permanent mod. You won't be able to use it for anything other than IR photography again (unless you keep the cut filter and replace it, but that rather defeats the point). If you don't think that you are technically gifted enough to modify a digital camera for IR photography, fear not. At the end of this article I will post a link to a simple IR camera hack that virtually anyone can do in about fifteen minutes to a half hour.

With digital cameras, you basically have two methods available to conduct IR photography. Removing the IR cut filter above is the most effective method, producing the best results. Another method is what I like to call the "brute force method". Most all digital cameras are so IR sensitive that there is a little IR bleedthrough even when the cut filter is still in place. You can easily test this by holding up a television remote control to the lens of the camera and pressing a button. If the infrared emitter on the remote control sufficiently lights up in a strobe light pattern, you should be able to use the brute force method with your camera. Basically, with the brute force method, you will place your infrared filter on the outside of the lens and setup the camera for a long-exposure shot. This means that you will have to use a tripod, and this is not optional. With the long exposure shot, you will undoubtedly have to experiment with ISO settings (less ISO, less grainy) and white balance settings (tungsten works best for me). Take the photo trying your best not to nudge the camera when you press the button. A remote is especially helpful here, but if one is not readily available, you may wish to use the timer function on your camera to ensure that you don't touch or vibrate the camera during the exposure. Your photos using this method will be dark, and color shifted. The color channels have no meaning in the IR spectrum, so most will oversaturate with false color. Just desaturate and change to black and white. This is the hardest and least rewarding method of infrared photography, and my least favorite. Remember that the results won't be that great, because the IR cut filter at the sensor is blocking out just about everything but visible light and the IR pass filter that you are using at the aperture of your camera is blocking out all light but infrared. What you are left with is any IR bleedthrough that makes it through during the long exposure.

At this point, I should discuss the piece that is the heart of any good digital IR photography setup. The IR pass filter. This filter is placed over the aperture of the camera either by screwing into the threads of the barrel, or by means of a special adapter placed over the aperture. There are two types of IR pass filter that can be used, commercial and homemade. Commercial filters, made by Hoya, X-Nite, Wratten, and Corkin are the best and most durable. All of these manufacturers produce filters at various peak sensitivities, ensuring you capture the peak wavelength you are looking for. The Hoya R-72, for example, only passes wavelengths above 720 nm and is a good all around performer. The Hoya R-72 is very popular with IR enthusiasts, and is a good starting point. You can usually pick one up for about fifty dollars online, depending on the thread diameter of your camera. You can also augment your setup with other filters at higher wavelengths to experiment and see which ones work best for different environments. If you don't want to shell out the dough for an IR pass filter made of glass, you can get a gel sheet (Wratten 89b) and cut it to fit. The cost for this alternative is substantially cheaper. Another thing to consider if purchasing a filter for your camera is that if you have other IR capable cameras that you wish to use it with, it needs to match the thread diameter of the other cameras, or you will need to purchase adapter rings to fit your other cameras.

Commercially available filters may be too expensive for someone who wished to merely experiment with IR photography. Innovative people have discovered homemade solutions which work very well and can be used in the same fashion. In the homemade IR filter world, there are basically two ways to go. Floppy disk material and exposed film. Since many camera apertures are larger than the biggest single piece of collective material with either film or floppy disk material, what you would want to do with these (if you can) is cut the pieces to fit over the sensor itself and not the aperture of the camera. The first method, floppy disk material, is just as simple as it sounds. Take a 3.5 floppy disk (they are getting kind of rare, though) and open the case. Take out the disk and cut a piece of the dark disk material till you have enough to cover either the aperture of the camera (easy enough for smaller point-and-shoots) or the sensor.

The second homemade method (which I think yields better results) is the exposed film negative method. Here you will take a piece of 35mm film negative that has been exposed and processed (by exposed, I mean only to light, not to pictures). An example of this is the part of the film that is exposed when you load the film canister into the camera. If you don't have any negatives with black portions still lying around the house, you can make your own. Simply purchase a canister of 24 exp. 35mm film from your local Wal-Mart or Walgreen's. Take and open the package, pull out about 4 or 5 inches of film, and wind it back into the film canister. Take it to the developer, and get it developed. Explain to them that you are aware that there are not any pictures on the film, so you do not need any prints. Explain to them that you only need the processed negatives. You may get some funny looks, but you can explain if you wish that you are using the exposed negative filter to make an infrared filter. They might even give you some trimmed black pieces from the beginning of other rolls that have been developed. At any rate, simply cut two pieces of the same size to place over either the aperture or the sensor. The double piece of film filter method will transmit less than three percent of visible light below 600 nm. This method is my favorite and makes a very effective homemade infrared filter.

A few considerations for the application of both commercial and homemade IR pass filters.

1.) When making a homemade filter (film or floppy disk material) for the aperture of the camera, make sure that you construct a housing that allows no light leakage. This will ruin your pictures

2.) When constructing a homemade filter housing to go over the expanding focus tubes of modern point and shoot digital cameras, make sure that it does not fit too snugly over the tube. If it binds, it can destroy the focusing motor and you will be left with a camera that will only serve as a paperweight.

3.) When using a commercial or homemade filter with a camera supporting the Niteshot™ feature, remember to use either a polarizing filter or neutral-density filter in addition to the IR pass filter. Remember with the restricted camera settings of the Sony Niteshot™ mode, it is designed only to be used a night. Daylight use can damage the system unless you take it down a few F-stops with the use of polarized or neutral density filters. This is the best system for non-modified IR setups and it is not permanent since you can still use your Sony in normal shooting modes. I have the DSC-V1 used in this configuration and I love it.

4.) Remember that if you choose one filter with a thread diameter for a specific camera and you want to use it with another camera that has a different barrel thread diameter; you will need to buy the appropriate adapter rings.

5.) Optically, homemade filters never match the clarity of a commercially available filter.

6.) If shooting at night, you will still need a strong IR light source.

7.) Finally, despite what you may read elsewhere, you do not need a separate IR filter for the flash of your camera. The aperture filter will filter out any visible light components of your flash. Odds are that it won't work anyway, as you will need a strong light source for the autofocus system to work anyway.

So if you want to try your hand at digital infrared photography, you can either modify the camera with good results, use a Sony camera with Niteshot™ and a good IR filter (and neutral density filter for daylight) for a turn-key solution, or use the brute force method and pray for good results. Personally I like the Sony solution, offers the best in autofocus and clarity. I did promise earlier that I would include information for a camera that was very easy to modify and would produce great results. The camera is the AIPTEK DV-4100M (available for 19.00 on AIPTEK.COM). It utilized a compact flash card and is capable of still photography and video shorts. The camera isn't exactly cutting edge technology, but it is highly IR sensitive and makes it a great (and easily affordable) candidate for modification. I learned of this modification at http://www.deadscience.com (vidcast #49) and owe Rob Fitzgerald my gratitude for posting this information. Basically you will need one piece of exposed film (not two as mentioned above, one works fine for this camera) and a little bit of patience. You will disassemble the camera, remove a sticker containing the IR cut filter, and replace it with the exposed film filter material. Reassemble and you are good to go. I also put together a blog with photos and step-by-step sequence for doing this mod. It can be found at

http://blogs.myspace.com/index.....fm?fuseact...logId=475779825

Here are some internet resources for infrared digital photography:

General IR Photography:

http://dpfwiw.com/ir.htm

http://infrareddreams.com/how_.....oot_ir.htm

http://www.paranormalghost.com.....t_tech.htm

http://en.wikipedia.org/wiki/I.....hotography

http://www.wrotniak.net/photo/infrared/

http://www.cocam.co.uk/CoCamWS.....FRARED.HTM

http://www.echeng.com/photo/infrared/

http://www.apogeephoto.com/may.....2003.shtml

http://diglloyd.com/diglloyd/f...../Infrared/

Homemade Filters:

http://www.instructables.com/i.....A-better-d...stunning-digit/

http://www.photoaxe.com/how-to.....ake-your-o...graphy-filters/

http://www.metacafe.com/watch/.....5292/take_...digital_camera/

http://www.diyphotography.net/.....ke_infrare...amera_ir_filter

Commercial Filter Comparisons:

http://homepage.mac.com/scho/M.....rcomp.html

http://www.beyondvisible.com/B.....ilter.html

http://www.photographyreview.c...../cat/lense...42_3133crx.aspx

http://diglloyd.com/diglloyd/f.....e/CoastalO...4/spectral.html

As applied to paranormal:

http://www.ustream.tv/channel/.....adscience2

http://www.lowcountryparanorma......com/index....ed_photography/

http://www.ghostsrus.com/Scott.....fared.html

Some famous (or infamous) IR ghost photos:

http://www.graveyards.com/IL/C.....ghost.html

http://images.google.com/imgre.....imgurl=htt...sa%3DN%26um%3D1

Great writeup, Andy. Thanks for posting that.

I've been wondering what I'd see with a FLIR Thermography camera, but I don't feel too safe borrowing the one from work to haul around on investigations. Something tells me the boss wouldn't look too favorably on the idea.

Thanks,

Andy

Primer for Introductory Infrared Photography and Paranormal Applications

By Andrew Selfridge

Ghosts and spirits seem to occupy an unseen world that is all around us, interacting with our own at their leisure. What if we were able to see into that unseen world, even if only just a small portion? Would it reveal answers to these mysterious phenomenon or would it merely eliminate yet another small portion of the electromagnetic spectrum as a candidate for spirit observation.

Being able to see in other spectrums of light has often been thought to give the observer an edge when dealing with visually documenting paranormal or supposed paranormal phenomena. One popular area for such study is infrared photography and video. Infrared (IR) refers to the spectrum of light wavelength located between 700 and 1400 nanometers (this figure fluctuates depending on source but that is the core range of the near-infrared). Actually, wavelengths in this range, although commonly referred to as infrared in the industry and where applied to paranormal research, is actually known as the near-infrared (NIR). In the context of paranormal applications, these terms tend to be used interchangeably, and although it is a bit of a misnomer, I will refer to the near infrared spectrum as IR or infrared for the duration of this article.

What is so special about this spectrum of light? Aside from the fact that we can't see it with our naked eyes (actually, dark-adapted eyes can detect near IR at the lower end of the spectrum) it is often thought that spirits can use this spectrum of light to manifest. Perhaps this mentality was borne from the famous infrared photo of "John" the supposed playful spirit that supposedly haunted the Toys-R-Us store in Sunnyvale Ca. in the late seventies. The case received a lot of publicity and controversy, but one thing that came from the case was a grainy, blurry black and white infrared photo showing was people described as the ghost of "John" leaning against an aisle rack. Witnesses reported that there was not anyone standing in the spot where the IR photo showed a person leaning against the rack. Another popular infrared photo was taken at the infamous Bachelor's Grove cemetery in Midlothian IL. The photo, a black and white IR shot, depicts a woman sitting on a bench in a white, flowing gown. The picture was taken during the daylight and witnesses again reported no one present in the shot while it was taken. This shot is commonly referred to as the "Madonna of Bachelor's Grove".

The popularity of the Niteshot™ feature on Sony branded cameras is also a testament to IR popularity in the paranormal field. With this technology becoming cheaper and easier to put in the hands of the average consumer around 1998, total dark infrared videos became a staple in many paranormal investigations. IR video served two purposes for the investigator. It allowed for the complete illumination of total darkness (0 lux) environments while also allowing the investigator to see any infrared video anomalies that might be present during the video. This was an extreme help to investigators everywhere, because the clarity afforded by this system was far better than night vision scopes using image intensifier technology. Prior to these Sony systems, if an investigator wished to film in total darkness, he or she would have to adapt a night-vision scope to their video equipment. The problem with this is that most nightvision scopes that are within the price range of the average investigator were referred to as "generation 1" devices. Generation 1 night vision scopes used a vacuum tube image intensifier to amplify light. This optic system resulted in a very strong fish eye effect, with distortion and chromatic aberration at the outside edge of the field of view. This also resulted in clear, distortion-free viewing only in the center 30 percent of the picture. This is why the Sony systems were welcomed with open arms from investigators everywhere.

There are limitations to the Sony Niteshot™ systems that need to be taken into consideration. Despite the fact that their picture quality was far superior to the night vision scope method, their sensitivity to total darkness without some form of infrared illumination was abysmal. These systems required ambient light, in the form of infrared illuminators, to function in 0 lux. Sony addressed this shortcoming with the SuperNiteshot™ feature where the image was brightened by extended exposure. The problem with using this feature in any type of video is that fast moving objects created ghosting artifacts, and usually identifiably benign objects such as bugs or dust took on a Spielberg-like poltergeist visual effect. Sony also introduced the Niteshot™ feature into several models of digital point-and-shoot cameras, allowing for infrared photography. These can also be used for daylight IR photography, but more on this later.

In the past, if you wished to photograph the IR spectrum, it usually meant that you needed a single-lens reflex (SLR) camera and special film. Prior to the advent of digital CCD and CMOS sensors and digital cameras in general, advanced photography required the use of an SLR camera so that exposure times and aperture could be controlled manually. Even after digital photography took off, most consumer based systems were point-and-shoot with limited control over shot variables. This meant that if you were interested in IR photography, you still had to use the SLR camera and IR film. Using infrared film was especially cumbersome due to special handling instructions. Infrared film needed to be kept refrigerated before loading. Loading and handling of the film was to be done in darkness, and developing as well as initial purchase were slightly more expensive than regular film. These factors made using IR film a hassle, and discouraged many folks from trying to use it.

Fast forward a few years and you come to a time where digital photography has revolutionized the way people photographically document paranormal research. One unexpected side-effect of the digital revolution was that the CCD and CMOS image sensors were highly sensitive to the IR range (and ultraviolet as well). Manufacturers noted that this would saturate their images, so they placed a piece of glass coated with a special optic film known as an IR cut filter. Basically it allowed only visible light wavelengths to pass through to the image sensor. This cut filter would stabilize color levels in visible light, but basically makes infrared photography all but impossible. In Sony Niteshot™ products, this filter (sometimes referred to as a hot mirror) is removed from the image sensor and the color values are dropped in favor of that green hue (green is used in most night vision applications because the human eye can distinguish more shades of green in low light than any other color). Early adopters of Sony products also found that with longer exposures and a good infrared filter, certain materials of clothing became transparent in infrared. Afraid of what that would mean for Sony's liability when these cameras were used improperly, the company restricted the camera's aperture and exposure settings when in Niteshot™ mode. With the new camera settings in effect, Niteshot™ mode restricted the user to only taking pictures at night.

Digital camera manufacturers have done a fine job of making sure that their products are used in visible light applications only. Since we know that the image chips are capable of infrared and uv sensitivity and that they are only being blocked by the use of a mechanical cut filter, modifying these cameras for shooting in the infrared. If you removed the cut filter and replaced it with a piece of glass (so as not to change the focus of the optic system) and used a commercially available filter, you could effectively shoot in the infrared spectrum without the use of special films. There are services available for those folks that aren't technically gifted with taking their camera apart and modifying it. They will modify it for a charge (usually pretty expensive) and you can shoot IR at your leisure. It should also be noted that if you modify a digital camera for use with IR photography, that it is a permanent mod. You won't be able to use it for anything other than IR photography again (unless you keep the cut filter and replace it, but that rather defeats the point). If you don't think that you are technically gifted enough to modify a digital camera for IR photography, fear not. At the end of this article I will post a link to a simple IR camera hack that virtually anyone can do in about fifteen minutes to a half hour.

With digital cameras, you basically have two methods available to conduct IR photography. Removing the IR cut filter above is the most effective method, producing the best results. Another method is what I like to call the "brute force method". Most all digital cameras are so IR sensitive that there is a little IR bleedthrough even when the cut filter is still in place. You can easily test this by holding up a television remote control to the lens of the camera and pressing a button. If the infrared emitter on the remote control sufficiently lights up in a strobe light pattern, you should be able to use the brute force method with your camera. Basically, with the brute force method, you will place your infrared filter on the outside of the lens and setup the camera for a long-exposure shot. This means that you will have to use a tripod, and this is not optional. With the long exposure shot, you will undoubtedly have to experiment with ISO settings (less ISO, less grainy) and white balance settings (tungsten works best for me). Take the photo trying your best not to nudge the camera when you press the button. A remote is especially helpful here, but if one is not readily available, you may wish to use the timer function on your camera to ensure that you don't touch or vibrate the camera during the exposure. Your photos using this method will be dark, and color shifted. The color channels have no meaning in the IR spectrum, so most will oversaturate with false color. Just desaturate and change to black and white. This is the hardest and least rewarding method of infrared photography, and my least favorite. Remember that the results won't be that great, because the IR cut filter at the sensor is blocking out just about everything but visible light and the IR pass filter that you are using at the aperture of your camera is blocking out all light but infrared. What you are left with is any IR bleedthrough that makes it through during the long exposure.

At this point, I should discuss the piece that is the heart of any good digital IR photography setup. The IR pass filter. This filter is placed over the aperture of the camera either by screwing into the threads of the barrel, or by means of a special adapter placed over the aperture. There are two types of IR pass filter that can be used, commercial and homemade. Commercial filters, made by Hoya, X-Nite, Wratten, and Corkin are the best and most durable. All of these manufacturers produce filters at various peak sensitivities, ensuring you capture the peak wavelength you are looking for. The Hoya R-72, for example, only passes wavelengths above 720 nm and is a good all around performer. The Hoya R-72 is very popular with IR enthusiasts, and is a good starting point. You can usually pick one up for about fifty dollars online, depending on the thread diameter of your camera. You can also augment your setup with other filters at higher wavelengths to experiment and see which ones work best for different environments. If you don't want to shell out the dough for an IR pass filter made of glass, you can get a gel sheet (Wratten 89b) and cut it to fit. The cost for this alternative is substantially cheaper. Another thing to consider if purchasing a filter for your camera is that if you have other IR capable cameras that you wish to use it with, it needs to match the thread diameter of the other cameras, or you will need to purchase adapter rings to fit your other cameras.

Commercially available filters may be too expensive for someone who wished to merely experiment with IR photography. Innovative people have discovered homemade solutions which work very well and can be used in the same fashion. In the homemade IR filter world, there are basically two ways to go. Floppy disk material and exposed film. Since many camera apertures are larger than the biggest single piece of collective material with either film or floppy disk material, what you would want to do with these (if you can) is cut the pieces to fit over the sensor itself and not the aperture of the camera. The first method, floppy disk material, is just as simple as it sounds. Take a 3.5 floppy disk (they are getting kind of rare, though) and open the case. Take out the disk and cut a piece of the dark disk material till you have enough to cover either the aperture of the camera (easy enough for smaller point-and-shoots) or the sensor.

The second homemade method (which I think yields better results) is the exposed film negative method. Here you will take a piece of 35mm film negative that has been exposed and processed (by exposed, I mean only to light, not to pictures). An example of this is the part of the film that is exposed when you load the film canister into the camera. If you don't have any negatives with black portions still lying around the house, you can make your own. Simply purchase a canister of 24 exp. 35mm film from your local Wal-Mart or Walgreen's. Take and open the package, pull out about 4 or 5 inches of film, and wind it back into the film canister. Take it to the developer, and get it developed. Explain to them that you are aware that there are not any pictures on the film, so you do not need any prints. Explain to them that you only need the processed negatives. You may get some funny looks, but you can explain if you wish that you are using the exposed negative filter to make an infrared filter. They might even give you some trimmed black pieces from the beginning of other rolls that have been developed. At any rate, simply cut two pieces of the same size to place over either the aperture or the sensor. The double piece of film filter method will transmit less than three percent of visible light below 600 nm. This method is my favorite and makes a very effective homemade infrared filter.

A few considerations for the application of both commercial and homemade IR pass filters.

1.) When making a homemade filter (film or floppy disk material) for the aperture of the camera, make sure that you construct a housing that allows no light leakage. This will ruin your pictures

2.) When constructing a homemade filter housing to go over the expanding focus tubes of modern point and shoot digital cameras, make sure that it does not fit too snugly over the tube. If it binds, it can destroy the focusing motor and you will be left with a camera that will only serve as a paperweight.

3.) When using a commercial or homemade filter with a camera supporting the Niteshot™ feature, remember to use either a polarizing filter or neutral-density filter in addition to the IR pass filter. Remember with the restricted camera settings of the Sony Niteshot™ mode, it is designed only to be used a night. Daylight use can damage the system unless you take it down a few F-stops with the use of polarized or neutral density filters. This is the best system for non-modified IR setups and it is not permanent since you can still use your Sony in normal shooting modes. I have the DSC-V1 used in this configuration and I love it.

4.) Remember that if you choose one filter with a thread diameter for a specific camera and you want to use it with another camera that has a different barrel thread diameter; you will need to buy the appropriate adapter rings.

5.) Optically, homemade filters never match the clarity of a commercially available filter.

6.) If shooting at night, you will still need a strong IR light source.

7.) Finally, despite what you may read elsewhere, you do not need a separate IR filter for the flash of your camera. The aperture filter will filter out any visible light components of your flash. Odds are that it won't work anyway, as you will need a strong light source for the autofocus system to work anyway.

So if you want to try your hand at digital infrared photography, you can either modify the camera with good results, use a Sony camera with Niteshot™ and a good IR filter (and neutral density filter for daylight) for a turn-key solution, or use the brute force method and pray for good results. Personally I like the Sony solution, offers the best in autofocus and clarity. I did promise earlier that I would include information for a camera that was very easy to modify and would produce great results. The camera is the AIPTEK DV-4100M (available for 19.00 on AIPTEK.COM). It utilized a compact flash card and is capable of still photography and video shorts. The camera isn't exactly cutting edge technology, but it is highly IR sensitive and makes it a great (and easily affordable) candidate for modification. I learned of this modification at http://www.deadscience.com (vidcast #49) and owe Rob Fitzgerald my gratitude for posting this information. Basically you will need one piece of exposed film (not two as mentioned above, one works fine for this camera) and a little bit of patience. You will disassemble the camera, remove a sticker containing the IR cut filter, and replace it with the exposed film filter material. Reassemble and you are good to go. I also put together a blog with photos and step-by-step sequence for doing this mod. It can be found at

http://blogs.myspace.com/index.....fm?fuseact...logId=475779825

Here are some internet resources for infrared digital photography:

General IR Photography:

http://dpfwiw.com/ir.htm

http://infrareddreams.com/how_.....oot_ir.htm

http://www.paranormalghost.com.....t_tech.htm

http://en.wikipedia.org/wiki/I.....hotography

http://www.wrotniak.net/photo/infrared/

http://www.cocam.co.uk/CoCamWS.....FRARED.HTM

http://www.echeng.com/photo/infrared/

http://www.apogeephoto.com/may.....2003.shtml

http://diglloyd.com/diglloyd/f...../Infrared/

Homemade Filters:

http://www.instructables.com/i.....A-better-d...stunning-digit/

http://www.photoaxe.com/how-to.....ake-your-o...graphy-filters/

http://www.metacafe.com/watch/.....5292/take_...digital_camera/

http://www.diyphotography.net/.....ke_infrare...amera_ir_filter

Commercial Filter Comparisons:

http://homepage.mac.com/scho/M.....rcomp.html

http://www.beyondvisible.com/B.....ilter.html

http://www.photographyreview.c...../cat/lense...42_3133crx.aspx

http://diglloyd.com/diglloyd/f.....e/CoastalO...4/spectral.html

As applied to paranormal:

http://www.ustream.tv/channel/.....adscience2

http://www.lowcountryparanorma......com/index....ed_photography/

http://www.ghostsrus.com/Scott.....fared.html

Some famous (or infamous) IR ghost photos:

http://www.graveyards.com/IL/C.....ghost.html

http://images.google.com/imgre.....imgurl=htt...sa%3DN%26um%3D1