Wed Jan 18, 2012 9:39 pm by Violaetor
I have a D40 with an R72 IR filter, the D40 has a very 'poor' low pass filter over the CCD which blocks only about 85-90% of infrared, and the IR filter in that range blocks about 95% of natural light, so net you are left with 5-10% infrared. The D40X has a much better ccd filter and leaves next to no IR spectrum in (if you have one don't waste the money on a filter).
Also there are real filters usually $50-150, and ALOT of just red glass, if it seems to good to be true, it probably is.
True infrared photography is only Black and white, never color... ever. Colored IR photos are a by-product of the most used technique to convert digital IR to the proper tonal range, which most people find appealing (peach/lavender/baby blue tones) so they leave it that way.
Also quite interesting is that the focal range of infrared light is about 8-12 inches closer to you than visible spectrum. So if you have your subject in focus and take a picture in infrared it will always be out of focus, which adds to the true ethereal feel of IR photography.
Think about that for a while, the infrared version of someone is standing closer to you than the real person...
Also as far as the whole x-ray thing goes, its pseudo accurate, but the more reflective an object is the more it will show in IR photos, so clothes which are more light absorbent/porus will allow the IR light to pass through to the more reflective skin/underwear which has a tighter "knit". Making it more visible under the right conditions, mainly VERY bright days with no cloud cover.
The best way to test your IR filter/camera is to go into a completely dark room, set your F/1.4-3.5 , SS to 10 seconds , then take a picture of your self going mental with your TV remote or similar pointed at the camera (pushing buttons obviously) observe the results, black image? you've been hornswaggled! crazy lines and dots of light? you got yourself a functioning IR camera!