When these infrared filters are used together with infrared-sensitive film or sensors, very interesting “in-camera effects” can be obtained; false-color or black-and-white images with a dreamlike or sometimes lurid appearance known as the “Wood Effect.”

The effect is mainly caused by foliage (such as tree leaves and grass) strongly reflecting in the same way visible light is reflected from snow. Chlorophyll is transparent at these wavelengths and so does not block this reflectance (see Red edge). There is a small contribution from chlorophyll fluorescence, but this is extremely small and is not the real cause of the brightness seen in infrared photographs.

Source

Yes, I’m serious, this it’s not a joke. You can build filters for your camera (either digital or film).
And yes, it’s incredible easy.
• homemade infrared filter: a piece of developed unexposed slide film OR a floppy disk !
• homemade blue filter: a piece of exposed developed slide film with methyl blue
• homemade yellow filter: a piece of exposed developed slide film with methyl yellow

IR Filter

For obtaining the home made IR filter you need: piece of developed unexposed slide film or a floppy disk. You must go at the photo store and ask for developing the unexposed film.

The home-made filter typically begins transmission at around 710-730nm. “Congo Blue” theater gels are designed to pass IR light in order to avoid damage from heating.
When combined with red filters which block their visible blue, the combination is reported to pass the shorter wavelengths of infrared up to around 720nm.
A piece of double-side polished silicon works as an infrared filter with a relatively sharp cutoff of about 1050nm.
However, there is something else that works too: making a IR filter out of a floppy disk!
Here are some quick example photos made by a friend of mine. The interesting thing is that he had to use 13 seconds exposure and ISO 100 to get something from the candles. It’s clear that the filter is not a professional one or a useful one but it’s fun to play with it.

For this IR Filter to make “wonders” you need patience, a steady hand or a tripod and a lot of light and eventually not moving objects.
It’s very important to place the filter correct on the camera.

Andrew Davidhazy determined how and why is this infrared method really possible, and you can read his article here. Prof. Davidhazy is a Professor of Imaging and Photographic Technology at RIT, the Rochester Institute of Technology.

Colored Filter

I’m going to explain something I made about 2 years ago. I read about it in an old book my parents had about film photography and start wondering in the town asking anyone for help but they all looked at me like I was crazy.
I had a roll of 120 slide film (it’s bigger than 35mm film, but hard to find today in stores) from my parents who used to photograph with old Russian film cameras. Some frames of it were empty so I cropped them as in the images. So this part was easy.
The next thing, however, not easy anymore: I had to find “methyl blue”, “methyl green” and/or “methyl yellow”. These are chemical substance that I had no idea where should I get them from. In the end, I found out that methyl blue is used for aquariums so I provided myself (very cheap) a little bottle from a pet shop.
Then I mixed it with some water, otherwise the filter would have been very very dark, almost black.
The more water you add, the lighter the color of the filter will be. I placed the film in the prepared substance for about 5 minutes or less (depending on the concentration of the mixture). Then I turned the film on the other side to get a uniform color on both sides.

In conclusion, you can make as many filters as you want, in different tones. The only problem that remains is placing the filter on the camera. All you need to know is that you must put it very close to the lens so that the camera won’t focus on it. The rest it’s all about your imagination.

Tags: infrared filter, IR filter, home made filter, colored filter, blue filter, green filter, yellow filter, cheap fillter, free filter, selfmade filter, self made filter, inprovised filter, camera filter, photo filter, photographic filter, impovised photo filter, improvised infrared filter, improvised IR filter

The other attributes of infrared photographs include very dark skies and penetration of atmospheric haze, caused by reduced Rayleigh scattering and Mie scattering (respectively) in the atmosphere compared to visible light. The dark skies, in turn, result in less infrared light in shadows and dark reflections of those skies from water, and clouds will stand out strongly. These wavelengths also penetrate a few millimeters into skin and give a milky look to portraits, although eyes often look black.

In other words, generally, objects that appear quite dark at visible wavelengths may be very bright in the near IR.

Some cameras are designed to be more infrared sensitive: Minolta Dimage 7 (D7), Nikon CoolPix 950, Oly C-2020Z, Oly C-2000Z, Canon Pro70.
If you are interested in infrared photography on film camera, read this article and take this under consideration too.

Chromasoftware launched their interpretation of a Photoshop IR filter. The plug-in emulates the look of the infra-red film and it’s designed to be usable with the landscape photos as well as portraits. You can download a demo version from Chromasoftware here.

A book about infrared photography.

Tags: IR Filter , Infrared Photography, Chromasoftware, Hoya