Night lights with an Infrared filter

I have had a lot of fun recently doing night photography. I became intrigued with the prospect of doing the classical car light trails, but using long exposures through an IRĀ filterĀ (Hoya R72 Infrared). At night, there are of course not many sources of scattered IR light, but I was curious about the results.

Los Angeles freeway traffic capture in Infrared I
Los Angeles freeway traffic capture in Infrared II

The images in my Los Angeles gallery on PBase speak for themselves. Interestingly, the results are somewhat soft, probably through diffusion of IR light, compared to the same view seen without an IR filter. This provides an ethereal feel to the image, which I like. I have not tried very long exposures yet (i.e. longer than the 30 seconds limit of my digital camera), but I will soon.

The only challenge with IR photography when using an IR filters in front of a lens is the need to prefocus without the filter on, and then make sure that screwing the filter back does not disturb the lens’ focus. I used Canon’s excellent 85 mm f/1.8 prime lens for this work (58 mm filter size), but any other lens would be fine. These filters can be expensive, so if you are trying this technique for the first time, it is a good idea to rent the filter, or purchase one of the smaller filter sizes like I did.