Last week I received a question from a reader about shooting IR photos with their digital camera. The question was, do they need to get their camera converted to IR to get good results? The problem is that there aren’t any definitive answers for this one. It’s possible to shoot IR with your unaltered digital camera but it will be a different experience than shooting with a converted camera.
Digital cameras are extremely sensitive to infrared light. The fact is that they are so sensitive that camera manufacturers put an IR blocking filter in front of the sensor to cut down on the effects of IR on your images. This is also known as a hot mirror or IR cut filter. The filter doesn’t completely eliminate all IR light so by using an IR pass filter, you can still achieve a good result but your exposures will be extremely long in duration. For example, take a look at this IR image I shot at Great Falls, VA.
The shot was made on an unaltered digital SLR. Using an 87 IR pass filter, I had to raise the ISO to 640 and shot wide-open at f/2.8 for 30 seconds to get a decent image. The long exposure is a result of the IR blocking filter trying to filter out the IR light. The pass filter, on the other hand, is only letting through IR while blocking visible light. This push and pull is the reason for the extended exposure times. The other problem with this method is that you risk added noise in the image due to the long exposure times.
You other alternative is to get your camera altered by having the blocking filter removed and having a pass filter installed in its place. There are multiple advantages to this option. The first is that, since the filter is installed in front of the sensor, you will be able to see perfectly through the viewfinder when shooting. If you are using a filter in front of your lens on a non-converted camera, you will have to set up the shot and focus prior to putting on the filter. This is because the IR filter is so dark that you won’t be able to see through it. Another advantage to using the converted camera is that it let’s you use fairly normal exposure times and settings, much like you would with a regular DSLR. In the example below made with a converted camera, the ISO was set to 200 and the camera was set to f/16 at 1/60 of a second. This makes it possible to shoot IR images without the trouble of lugging around a tripod.
The problem with the converted camera is that you can’t use it for regular photography. Once it’s converted you will only be able to use it for shooting IR images, which is why so many photographers have their spare cameras converted. If you choose to use a filter on your unaltered camera, you can always use your camera to take regular images by just removing the filter.
So how much will it cost to start shooting IR? Well, a filter like the 87, 89B, or the R72 will run anywhere from $85 to $150, depending on the size of the filter (you need to get one that will fit the thread diameter for the lens you want to use). If you want to go with the converted camera, you will pay around $350 for the filter and conversion service (prices are dependent on the type of camera you are getting converted). Conversion isn’t just for DSLR cameras either. You can have older point-n-shoot cameras altered as well. My choice for conversions is Life Pixel but there are others out there that are doing the same type of work.
Which ever method you choose, I am sure that once you start shooting in the IR spectrum, you will be forever hooked.