Infrared Photography




Photographing light in the infrared end of the spectrum can produce some striking and beautiful images and it's something that you can have a go at quite easily.

Equipment

The method I use for infrared (IR) photography requires the following:

1 – A digital camera capable of detecting light at infrared wavelengths*
2 – A tripod (For those long exposures)
3 – Infrared filter (I use a Hoya R72) check eBay, expect to pay between £15 - £30

*See the following web page for a list of various cameras to check if yours will work:

http://www.jr-worldwi.de/photo/index.html?ir_comparisons.html

Locations

Infrared photography relies on reflected IR light; it therefore works best on sunny days. I try to photograph with the sun behind me illuminating what’s in front of the camera. For me, the draw of IR is the white glow it gives to green foliage so I like to photograph trees and other plants. Skies and water are reproduced dark and buildings take on a ‘greyish’ tone. Anywhere that buildings and foliage/water/sky come together should produce interesting results. Clear blue skies with a few clouds look the best as too many clouds can wash out your image. Locations to consider include graveyards, castles and forests.

Exposure

The IR filter blocks too much of the visible light spectrum for your camera to automatically set the WB. If your camera has a ‘one touch white balance’ setting, make sure to use it. Take a WB reading from a patch of grass in direct sunlight (with the IR filter attached) this lets the camera correctly balance the colour of your shot.

You’re going to need to use quite long exposures to get your picture which is why you’ll need a tripod. Depending on my location I’ll use between 2 seconds to 15 seconds. I also prefer to use as long a depth of field as possible so with a small aperture that’s going to increase the shutter speed needed. Experiment to find out what works best for your location.

Focus

Focus can be tricky in IR but with the R72 filter, I find that just enough visible light is allowed through for the auto focus to cope. Using your LCD display becomes difficult in IR so you’ll have to rely on your viewfinder for composition and trial and error to achieve the correct focus. Experiment, experiment, experiment.

Post processing

I process all my IR shots in Photoshop. Curves, auto levels and channel mixer are my tools of choice. In the channel mixer, with ‘red’ in the drop down menu, set the red slider to ‘ZERO’ and the blue slider to ‘100’. Now with ‘blue’ in the drop down menu, set the red slider to ‘100’ and the blue slider to ‘ZERO’. This swaps the red and blue channels.
Fiddle with these setting to your hearts content to find results pleasing to you.



Further things to try

You can now buy cameras that have been specially modified to take infared photos. These cameras allow shorter shutter speeds and smaller apertures and can produce incredibly sharp images. Such cameras are unable to take visible light photos properly though so you have to be sure you can justify the expense to take purely IR images.

I welcome any questions and discussion.

High Dynamic Range

I'm going to start this blog with one of the most recent things I've been having fun with... HDR. That is, High Dynamic Range imaging. I'm going to approach this from the point of view that most readers have either never heard about HDR or haven't had much luck with it in the past. If you fall into the former category, to put it simply, an HDR image helps us obtain evenly exposed photographs. I'm no expert but the following will outline what I've learned.

Step 1 - You're goin to need at least two differently exposed images from your digital camera one for the higlights and one for the shadows. A midtone shot would be nice but the example I'm going to look at uses only one.

Step 2 - You'll need some imaging software capable of HDR processing. I use Photomatix Pro but Adobe Photoshop CS2 is perfectly acceptable too.

Step 3 - A willingness to experiment and tinker with settings is a must for this operation :)

Ok so to start off, select your two images. I'm using two shots taken in Glencoe, Scotland.

This shot is clearly over exposed as we have lost all the sky detail and the top of the mountain is even affected. The rocks in the foreground however are clear and detailed.

In this shot I have used a slower shutter speed to get that lovely sky nicely
exposed but at the cost sacrificing detail in the foreground.

We need to combine these in Photomatix. This is easiy done by dragging the files into the Photomatix workspace or opening them from within the program itself an then selcting HDR>Generate. Untill recently, I had stopped at this step because it produces the following rather unpleasing result:

Not very nice. We've now lost nearly all of the foreground to ugly darknes and have some horrible banding in the sky. On top of that we're now encouraged to give up. But wait! The next step makes all the difference.

Select HDR>Tone mapping to open a whole lot of new options. The problem with HDR is that it contains far too much information for our monitors to display. Tone mapping helps to regulate what information is shown. Have a play around with the new options to find something that pleases you. It will vary from photo to photo so don't be scared to change things till you get an image you like.

Fiddling around with the Tone mapping options has given us a nice lovely sky and crisp clear foreground. A lot of HDR images that I've seen tend to over do the effect and create a false looking 'posterised' look. If you're aiming for that look it's not a problem but I prefer the image to look natural.

If there are any questions please ask :)

-Dave-