Tuesday, August 11, 2009

Digital Adventures In Infrared

IR Test (River Pano 50%)
Test image taken with my Canon G10 using an 850nm IR filter, coloured in PS during post.

Infrared photography has always intrigued me, there is something about white trees and dark skies that brings a surreal nature to the images. With the dawn of digital cameras came the apparent dusk of IR photography, IR blocking filters that are installed on the sensors almost rule out IR photography entirely. There are still a few methods left and that is what this post is about.

The IR blocking filters, sometimes referred to as "hot mirrors" apparently are not all created equal. Here is a website that lists various camera's sensitivity to the infrared spectrum, unfortunately it appears to be a little dated but you can see the variance between cameras.

One quick way to see how sensitive your camera is to IR is to point your TV remote at the lens and see if you can see the IR LED light up when you press buttons on your remote. This is only the first step however, even if you see some light it still may not be sensitive enough but its a good start!

Assuming your camera has some sensitivity to the IR spectrum you can try what I did, purchase an IR pass filter for your camera. This filter blocks the visible spectrum and lets the IR light in. Filters are available in various wavelengths, in my case I used an 850nm IR pass filter.

Since we're blocking out quite a bit of the spectrum with the IR pass filter and since our internal filter is blocking a lot of the IR our exposure times will suffer. The image at the top of this article took 4 seconds at F2.8 with an ISO of 200 in the midday sun. Other cameras and filter combinations may yield different results but you should bank on having to bring a tripod, hand holding is simply not an option.

Another, more dramatic option, exists to enable your camera to take IR photos. There are companies which will take your camera and remove the IR filter or hot mirror from the digital sensor. This method has its pros and cons, it will reduce your exposure times greatly but can also limit your camera to only being able to take IR photos. It has also been noted that most cameras will have problems with their auto focus mechanisms due to the change in thickness of the filter over the sensor. Personally I'm not that big an enthusiast that I'll be sending in my 5DMKII any time soon.

Bez Infrared Cropped small
IR image faked in Photoshop

If you don't like either of these options you can always try to fake it using an image editing program like Photoshop or Gimp etc. While the results vary as much as the methods and the fact that it can be very time intensive it can yield some interesting images and give you another avenue if other options are not possible.

My Gear
I've been buying more and more stuff from this great Hong Kong based site, the other day I read an article that claimed people had success using IR filters on their G10 by use of a special adapter. I quickly checked out my Hong Kong connection and sure enough I found a 58mm filter adapter for $8 and a cheap IR filter for $19. So for approx $30 I was willing to take a gamble and it appears to have paid off!

Good luck!

1 comment:

Jay said...

You answered my remaining questions about IR photography. I had an interest, realized the commitment required in the digital age, added to that my waning interest in scenery photography (not that it is your only option for IR, but a common one, no question) and I decided to pass. The gift cards burning a hole in my pocket were saved a put toward Pocket Wizards. A wise choice over IR IMHO, but that doesn't mean I don't enjoy looking at the images and the different viewpoint they provide.

I've faked it with a few PS actions, but it isn't the real thing.