Infra Red photographs are taken using only infra red light. Since human eyes cannot see infra red light we are then taking photos with invisible light. The first question that occurs is "How do we do that?". Before digital photography it was done with specially created infra red film. Because the film was sensitive to invisible light we had to load the film into our cameras in total darkness. I carried a light proof bag with sleeves for my arms. The camera and film were zipped into the bag, then I would insert my arms into the sleeves, open the camera, and load the film by feel.
With digital cameras it is both easier and more difficult to create infra red images but before that description let's take a look at the result. The first image shows the basic idea of what you get. First the image is usually a black & white or monochrome image. In film days that was the only possibility. The chlorophyll in green plants reflects a lot of infra red light and the blue sky shows very little therefore, as you see, the sky is nearly black and the trees appear to be snow covered. White clouds also reflect infra red and they appear very bright. The overall effect is a high contrast dramatic image.
So, how do we do this with a digital camera? Well working on our side is the fact that digital sensors are very sensitive to infra red light. This creates a problem for camera manufacturers because the sensors are so sensitive to infra red light that the camera's photos would not be good at all, so the maker has to put a filter in front of the sensor to block infra red light. This is great for regular photography but not for us if we want to take infra red (let's say IR from now on) images, so what do we do?
We need to purchase an IR filter which allows IR light to pass through and blocks almost all visible light. I can take my IR filter and hold it in front of my eye on a bright sunny summer day and I see nothing at all. It is completely black. If I look directly at the sun (very briefly please) I can see the sun but that is all. IR filters vary widely in price depending on quality and upon exactly which areas of the IR light are blocked and which are allowed through. Here my advice is to start with a less expensive one since you may find it works better for you than a very expensive one. That is difficult to explain but still true. My first digital IR images were created using a Kodak gelatin filter that I got for about $30.
With the filter on your camera you can see nothing through the viewfinder or the live view screen so you will have to focus first (oh, you MUST have a tripod). Once you have focused and put the filter in place you will have to experiment with exposure. My first shots using a small point-and-shoot camera were about 30 seconds long on a bright sunny day. The blocking filters on cameras have gotten better so you may have to go 45 to 60 sec. Your first test exposures are a "crap shoot" strictly a guess. If it's dark go longer if it's too light go shorter. In a few minutes you should have a decent shot.
Now here comes a surprise. The photo is not black & white. Since we are using a camera that separates red, green, and blue, the infra RED light we are using exposes the red pixels more than the green and blue so we have a very pink image.
Before we go any further I'll mention another way to create IR images. My first digital camera was a Nikon D100. When I upgraded to a D200 I kept my 100 as a backup and found I didn't use it. It laid in my camera case but never came out. An internet search revealed that there were quite a few companies and individuals out there who would convert digital cameras to IR cameras. They remove the IR blocking filter from the sensor and replace it with a filter that blocks visible light (similar to the one you use in front of the lens). Now that the blocking filter is removed your exposures are almost the same as a normal color camera and you no longer need a tripod and extremely long exposures. Remember you cannot take normal color photos with this camera any longer; it's IR only. Another warning: your meter will work but it will not necessarily be as correct as it used to be and you will find yourself compensating for images too dark and too light as you go. I found the cost of this conversion ranged from $100 to $400 and I advise you to research the provider before you send off your valuable camera and money. I would highly recommend the guy who did mine but he no longer does the modifications so you are on your own there.
Back to pink images. because infra red is closer to red than green or blue there is an over all pink cast to the images. There is more exposure to the red pixels than the green or blue BUT the green and blue get some exposure also and you can leverage this to create "false color" images. This is way beyond this post but fun to do.
Any photo editor will allow you to reduce saturation and create a black & white image. In Lightroom I adjust contrast highlights, shadows, blacks, and clarity, but in any editor you will be able to create a decent monochrome image. I chose the image you see here for a couple of reasons. First you can see that IR does not penetrate fog and by shooting this particular image in IR the grass and the sky are both light and the dark slacks and hair on my model stand out clearly.
If you like the effect, give it a try. There are many websites devoted to IR photography with detailed advice on how to get 'er done. As usual comments and questions are welcome. I promise to read and answer but I am sometimes slow so please excuse me if I seem unresponsive.
'Til next post: Keep Shooting.
Jim
No comments:
Post a Comment