I bought a infra red pass filter (says its 850nm passband) with a view of doing IR daytime photography, however I couldnt resist the urge to try deep sky imaging through it with my modded 350d. Heres a shot of the Lagoon Nebula, 30 mins imaging (6x5 mins ISO 1600). Its a 52mm diameter filter but with hi tech materials (cardboard and stickytape), I was able to temporarily hold it inside my focusser.
I didnt think Id get any nebulosity at all, but apparently the nebula does emit a small amount of infra red light. Absoloutely no visible light can be seen through it, even in bright daylight.
Scott
Yes I might see if I can come up with some sort of mapped colour image, all I need to do now is image it in 0III, but not tonight as the moon will be near it and reflections into the scope will be a problem
