November 29th, 2010, 10:05 AM
Hi, I shot some near infrared material with my (unmodified) HV20 and an infrared filter over the weekend..
YouTube - ir test 1 0 (http://www.youtube.com/watch?v=qAzSh20eDWk)
November 30th, 2010, 10:33 PM
Could you tell us what filter name and model number you used ?
What you did to the footage after it left the camera, (ie., did you desaturate the colours) ?
My understanding of IR and near-IR filters is that they remove unwanted IR or near IR that the camera sensor remains sensitive to. Your unmodified camera will not see more IR with one of these filters in place but will see less and your normal colour imaging, especially with added ND filtering will be improved.
If you are adding a filter which removes natural light (like a very heavy neutral density filter or welding glass eye protection) but allows IR or near-IR to pass, then open the lens iris wider, then gain up the camera to raise the level of IR which is breaking through the camera's own IR or near-IR filter, you would create a near-IR image.
I may be misunderstanding what you are doing. If so, then please forgive my assumptions. I also do not know if your camera has the "night shot" function built-in. On some consumer cams, this apparently is a switchable near IR filter, which when selected off and supplemental IR or near-IR lighting used, will yield genuine near-IR images. For daylight near-IR, people are selecting the night-shot function and adding very heavy ND filtering or welding glass elements to remove the visible light.
If you are related to John Seale ACS, ask him. He will give you far better information that I can on this topic, otherwise, posts by Chris Barcellos and Charles Papert are good to look up.
December 1st, 2010, 03:07 AM
Hi, its a hoya r72, the hv20 does not have a night shot mode but if you test it with a remote control, you can see that it the 'invisible' IR light from the remote is recorded by the camera.
Filming in full sunlight with a slow shutter speed, then making the image black and white in post will give the same effect as the video.
I dont think I am related to John Seale but I would dearly love to talk to him about his work anyway!