Friday, October 8, 2010

I Read Another Article That Was Wrong About Infrared.

I just saw another article about infrared photography where the author said the first thing you “must” do is have you DSLR converted to be able to do infrared work.  Rubbish, balderdash, phooey, and baloney.  I won’t go so far as to say it’s a scam, but removing the filter covering the sensor isn’t necessary.  It’s convenient, it makes hand held infrared possible and creates grab and go possibilities for the work, but your “normal” camera should be able to do infrared if you have a tripod and some patience.  Today’s image is a straight B&W infrared shot.  As originally shot it had a decidedly red cast to it.  There’s a reason for that.  It’s that Hoya R72 Infrared filter on the front of the lens.  It’s like looking through a welders mask.  You can’t see a darn thing through it.  An alternate use for it might be watching solar eclipses.  It’s dark enough to lower you light gathering power by about 3.5 Stops .  The reason I can be that specific is that I was shooting both Infrared and color shots of the same scene.  The technique is fairly simple.  To find out more about how to shoot both and why you’d want to shoot both, hot the “read more”.
The how is easy. I screwed the filter on by about a half a thread. That sealed any extraneous light out and allowed me to remove it quickly to take the color image that was the companion shot to the infrared. On, off, on, off for the whole time shooting in the state park I was visiting. Anyone passing by might have thought I was somewhat obsessive compulsive, doing the same thing over and over. What was actually going on is bracketing of exposures. I could figure out the exposure for the color shots. At least I could see through the eyepiece and compose the shot. The infrared shots were a crapshoot. I shot anything from .5 seconds to 10 seconds. To tell the truth, any of the infrared shots between 2 seconds and seven or eight seconds are pretty usable. So, the routine was: 1. Setup the shot without the filter in place. 2. Put the filter on. 3. Shoot. 4. Take the filter off. 5. Change the camera settings. 6. Shoot the color shot. 7. Change the Shutter speed higher or lower. 8. Put the IR filter back on and repeat the sequence. The reason for taking the color shot between each IR shot was due to clouds in some of the shots. There had to be the most minimal time differential between the IR and color shots to keep the clouds as closely aligned as possible. That brings us to the why of shooting both IR and color.

The image here shows the why. At times I wanted to be able to play with combined IR and color images. This isn’t new. You can find several (or many) articles about it by doing a Google search. It just gives an interesting look it the image and it’s something different. It hasn’t become as popular as HDR. It’s a niche technique and it’s something to keep in you hip pocket just in case a client is looking for “something different”.


黄清华 Wong Ching Wah said...

Beautifully photographed.
Have a good coming weekend.