Hi all
Though it was cloudy I got out the 850Nm infra red pass filter on my modded 350D F5.6, 1/90sec iso 200 hand held. Had to focus by trial and error.
I used Iris to process the image, decoding the raw image then converting the cfa back to a colour image, and made an interesting discovery. As it came up a perfect grey, that is no colour cast at all, it proves that the coloured dyes in the red green and blue pixels are all equally transparent to infra red light, so the camera effectively behaves like a monochrome sensor.
Thanks. Yes its amazing how well vegetation reflects IR light. I find it generally doesnt pick up heat from cars as it has to be fairly short wavelentgh IR light to be detected, eg almost glowing, perhaps the exhaust of a car thats been on a reasonable drive might show up. I should take a normal pic from the same position as a comparison.
Scott
Thanks
Heres the same scene, at night!
57 seconds (I just kept the shutter open for what I guess would be long enough) 50mm f1.8 @f1.8 ISO200
Totally overcast, windy and the rain had not long stopped.
Scott
I use to play with Kodak IR transparency fim back in the mid-70's and when
processed it produced funky false-color results which suited that era.
Did part of your camera's mod include removing the internal IR blocking filter?
It's interesting that the image ended up being monochromatic rather than
the CCD pixels with the red filtering being more sensitive than the blue and
green ones.
Looks better than the infra red ones of your street that you posted last year, Scott. Sort of clearer
It a wonder that the car didn't glow near the hot engine and exhaust area.
I think the camera has to be cooled alot to see the heat signature.
When they commissioned the Police Helicopter IR camera over here quite a few years back, they found this out the hard way, especially with a Nightsun Illuminator next door.
I use to play with Kodak IR transparency fim back in the mid-70's and when
processed it produced funky false-color results which suited that era.
Did part of your camera's mod include removing the internal IR blocking filter?
It's interesting that the image ended up being monochromatic rather than
the CCD pixels with the red filtering being more sensitive than the blue and
green ones.
Best regards
Gary
Yes, I bought the camera through Hutech. They remove the IR blocking filter and replace it with clear antireflection coated glass of equal thickness, that way autofocus si still accurate and the chip can recieve unfiltered IR light. It can "see" a hotplate before it gets to red heat.
For normal astroimaging I use an IDAS uv/ir filter where I dont want IR light coming through
Scott
