Infra Red – The Invisible Light

 

 

Take a good look around you and you’ll see and endless diversity of hues in all the colors of the rainbow: The grass is green, the sky is blue, the roses are red and the future is bright. Now imagine that on top of all the colors you can see, there are other ranges that are normally invisible to us, colors that for us don’t exist but they’re out there and for some animals they are a part of everyday life. I am talking about the Infra-Red (IR) spectrum and in this article I will show it to you. By the way, clicking on the small photos will enlarge them.

 

Content:

 

1.     Introduction

2.     What is Infra-Red?

3.     How can we see it?

a.     Film cameras

b.    Digital cameras

c.     IR filter

4.     What does it do?

5.     Photographing techniques:

a.     White balance

b.    Light metering

c.     Focus

d.    Aperture

e.     Shutter

f.     ND filter

g.    Location location location

6.     Compositions

7.     Post processing:

a.     Switching channels

b.    Adjusting hues

c.     Sharpening

8.     Summary

 

1.   Introduction – To be honest, I feel a little like a magician revealing a trick. I suppose most of you look at the photos and think “hmmm… Is it snow? But it can’t be, it was taken in Israel in the middle of summer, so what is it? Wooow”. In this article you will understand exactly how the technique works, it is one of the less common forms of photography and I think one of the more fascinating ones. Enjoy.

 

2.   Infra-Red – The spectrum of light that is visible to us is only a small portion of an enormous spectrum of short and long electro-magnetic waves. An example of the short-length waves are X rays and Gamma rays that are filled with energy and an example of the long wave-lengths is Microwaves and Radio waves.

 

Infra-Red light is divided into three groups: Near Infra-Red (Near IR) which is in the range of 700-1300 nm; Medium IR which is in the range of 1300-3000 nm and thermal IR which is in the range of 3000-30,000 nm. Thermal Infra-Red light is produced by warm objects while Near IR and Medium IR are reflected off objects just like visible light, which is produced by the sun. When it comes to photography, we will be dealing with the Near IR range.

 

 

3.   How can you see it? Well, you can’t. Seriously, unlike some animals, we can’t see Infra-Red light. But fortunately for us the camera can see it.

 

a.     With film cameras it is best to use a special IR film that is sensitive to that form of light. These kinds of films are used mainly in a special technique of capturing light, and most of them are black and white films and require special refrigeration.

 

b.    With digital cameras (like we love) the sensor is, fortunately, sensitive to Infra-Red light, so what’s the catch? Most cameras and especially the SLR ones contain a filter that blocks IR light and prevents it from ever reaching the sensor. The reason for it is to improve the final quality of the photo. How do I know that my camera is able to capture IR? A wise man taught me a trick: You take the television remote control, aim it at your camera and take a photo while pressing one of the remote control’s buttons. If you can see the remote control’s IR light bulb flash, the camera can capture IR, If not…Well then, I’m sorry. The most sensitive camera will show a sharp bright spot and the less sensitive ones will show a blurry smudged spot. The most IR friendly cameras are Sony’s, Minolta being the most advanced of them, the Nikon D70 (which I am using), Canon G3, G2 and more.

 

c.     So we have a camera, what now? We add the IR filter, whose purpose is to block all visible light except IR light, in front of the lens. The filter will look completely black to our eyes (because we are blind to IR light, remember?). The filters can be categorized according to the wave lengths of visible light that they block, for example Hoya R72 allows IR rays longer than 720 nm, the Hoya R90 (horribly expensive) allows IR rays longer than 900 and so on.

4.   What does it do? Well, so we’ve learned what IR light is, and how we can see it. But what is it good for? Infra-Red photography creates a very special effect of a dreamy photo out of this world because the hues that are shown are entirely different than those we see in reality, the foliage looks snowy white and the sky looks dark or even black. You can see landscapes that you are used to seeing every day in a truly “different light”. That is why I, and many others, like this photographing technique.

 

 

5.   Photographing techniques: “Enough with your babbling Roie, just tell us how to take the picture already…” Oh well, I didn’t know you’re so stressed. So here is how you perform the technique, step by step:

 

a.     White balance – Infra-Red hues are more than red (well duh…), they are so red that their white balance is off the scale of the automatic and preset WB in most cameras. That is why we need to perform manual white balance with a white piece of paper, or an 18% gray card to get the more precise colors, or perform the white balance on a green surface like grass to increase the effect of white foliage. If you think about it, it is better not to photograph with RAW because even with most RAW editing programs you can’t reach a white balance less than 2000 Kelvin degrees while the IR’s is much shorter.

 

b.    Light Metering – Light Metering should be performed with the camera in an evaluative metering mode, and don’t worry too much, in most cases the metering will turn out fine. You should watch out for burnt areas because in IR they turn out blue the more you get near them. If it’s necessary, you should apply some negative exposure compensation and then adjust levels in photoshop, but most importantly avoid burnt areas. It is highly recommended to switch to manual mode (M) to get the most accurate exposures with the best control.

 

c.     Focus – You should perform the focus before adding the IR filter to make sure that you focus correctly and switch to manual mode to maintain the focus. If you are lazy, you can use manual focus and estimate the distance (in that case automatic is better).

 

d.    Aperture – It’s recommended to photograph with relatively small apertures and avoid open ones. This is because we lose a little sharpness in IR photography and shutting the aperture helps a lot in that way. In compact cameras an aperture of F/5.6 and in DSLRs and aperture of F/11 should do the trick.

 

e.     Shutter – Due to two reasons, a small aperture and low IR sensitivity, we are forced to use slow shutter speeds, for better and for worst. Why better? Because a special effect is produced over water and clouds in very long exposures. Why worse? Because you need a tripod and it’s difficult to capture moving objects (people, animals etc.).

 

f.     ND filter – Sometimes it’s better to photograph with an ND filter that reduces the amount of light entering the camera even more in order to achieve longer exposures and improve the effect.

 

g.    Location – It’s best to shoot from a shaded place. First and foremost, because it's hot to stand in the sun, and second because the camera loves shooting from shaded places. In addition, I would recommend blocking the viewfinder in DSLR to prevent light for leaking into the system.

 

 

6.   Compositions – It’s possible to achieve very special images, but we can also use special compositions to get better effects. The following rules are only additions to the known laws of composition.

a.     Sky – the sky turns out dark and the clouds turn out bright. This creates an excellent and dramatic contrast that can contribute greatly to the photo.

b.    Foliage – we should attempt to capture special structures of foliage that can be interesting when we should keep in mind that all foliage will turn out completely white.

c.     Water – because of the long exposure water will appear with a very unique silky texture. This can be used and improved with reflection games.

d.    Structures – It’s very nice to photograph familiar structures with foliage around them and create a very dramatic photo that people will be awe-struck when viewing it for the first time.

e.     People – It’s pretty hard to incorporate people in the photo, and if you do try and photo them, it’s better not to show faces (unless the purpose is to spook). If you incorporate people or animals, then you should open the aperture a bit to shorten the exposure time.

 

 

7.   Post processing: After taking the photo, the job is far from over. We shall now switch to Photoshop to see how we improve the frame to a special and appealing look. I take it that you are familiar with the basics of Photoshop.

 

a.     Switching channels – When first opening the photo, we will see a photo like in the example attached, in brownish-red hues (depending on what type of white balance we used). This photo can be useful, but I also want to show you a result that is more soothing to the eye. We open the Image menu > Adjustments > Channel mixer and choose the later. A window will open like in the attached example. Under the red channel you should reduce the red from 100% to 0% and increase the blue from 0% to 100%, and on the blue channel do the opposite – decrease blue from 100% to 0% and increase red to 100%. There you have it, the channels are switched (as simple as with the TV…). (It is recommended to click on the images to enlarge them)

 

 

b.    Adjusting Levels – It might be that the photo is still not with the hues that we desire it to have and that is why we will adjust the levels properly (Ctrl+L) and adjust the color balance (Ctrl+B) to achieve colors that are more suitable to us, in the shadows, midtones and highlights.

 

c.     Sharpening – Because there is a certain degree of fuzziness, it is recommended to perform sharpening with Unsharp mask as necessary (reminder – Filter > Sharpen > Unsharp mask). I used the following parameters: Threshhold: 1, Radius: 2.0, amount: 80%.

 

d.    After the processing is done you should have a result similar to this. But of course you can perform different processings including the incorporation of a regular photo and an IR photo in two layers etc.etc. The sky’s the limit.

 

e.     Naturally, it's possible to present the photo in black and white with all the techniques of turning it black and white and not in color. The results are very interesting as well.

 

8.   Summary:

As we see, Infra-Red isn’t a very simple technique but despite that any one can use it (with the right equipment). I personally love this technique and I know that you can undoubtedly reach incredible results with it. I hope that this guide was clear and I hope you learned something new and enjoyed it.

Best Regards,
Roie Galitz
www.galitz.co.il

 

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