Saturday, March 27, 2010

Infrared Games - First take with a new filter

Well, I recieved my infrared filter and decided to see how it worked.  It worked better than I expected.  Though exposure times were somewhat longer through the filter, they were not too long.  I could see hand holding the camera for these exposures in the future (though in this case, I used one of those little flexible tripods).  I figured I would post a few pictures to show about what I am seeing.  Note, very little work has been done to optimize these (standard camera settings in most cases, I did not really try to lower the ISO for noise etc).  I will post more pictures in a more controlled environment using a few more cameras (and a better subject than this one). 

As it was easy, I used my Canon Powershot SD1100IS and Autumn's Panasonic Lumix DMC-FS3.  Note I am not listing the exposure parameters here (that will be for the more thorough test).  Note, none of these cameras are designed to do infrared photography, so the results might be less than optimal, but buying a camera designed for this is outside the scope (and price).  Most cameras try to limit infrared energy from hitting the sensor (to protect the normal image) making this a little tricky. 

The picture above is from the Powershot.  Notice the hazy section in the middle.  I have come to find (from a few online resources) that this is a comon problem using Canon for infrared.  Note - since Infrared is outside normal visible light, this is not affecting the normal image quality.  However it is something to note for infrared use.  You will see below that it is not as big of a deal as it is here. 

The picture above if from the Lumix.  This looks much lighter, and if there is a haze in the middle, it is not nearly as pronounced (it looks it here, but not when editing them).  Note, I am not sure if the lightness is a result of the exposure settings or something else (but will find out when I run a more thorough test). 

After looking at outputs from multilple sources online, the color cast does seem to change from camera to camera.  Technically there should be no color cast (as there is no color in the infrared spectrum), but since the filter does let a very small amount of visible light through (using a Hoya R72) that would tend to fool the camera to red.  Obviously, this is not the final output.  To remove the color cast, one would change this to a black and white image.  The reason to record in color, is to allow the best flexibility in making this change (using the color sliders in photoshop to change the contrast and darkness of the final image).  You will see what I mean in the next image.

Here is the final from the Powershot.  Notice the haze in the middle appears to be gone.  In reality, the haze ends up being a bit of a blueish region.  So when converting to Black and white, I get the image to the contrast I want using the red and magenta sliders, and then match the middle with the blue slider (and when done, a nice black and white infrared image).

Here is the Lumix image.  It is again a bit brighter (not sure if it is due to infrared sensitivity or just the exposure, this will be investigated in the future).  You can see the infrared affect really well here (the green trees come out white). 

So this is the first cut at a few pictures.  I want to test out a few other cameras, and do them in a better test environment (I want to go down to the lake, get some water in the picture, and some sky and have trees with leaves on them - this best shows the overall affect and will be the best for comparison).  As I may have a few week wait on the leaves, I may play some other games in the mean time. 

I figure while I work this out, I will post a little primer on infrared photography next.  Though this can be found on many other websites, I will try and break it down into some simple discussion (might have to borrow a few others pictures while I do this.  I will go over my setup (which is a nice cheap first cut - if it works well, might try something a little better).

Let me know what you think. 

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