Infrared filters

[Morph]

Just been leafing through a website of camera bits and bobs and came across infrared filters, what are these used for ?

[nytecam]

Originally Posted by Morph

Just been leafing through a website of camera bits and bobs and came across infrared filters, what are these used for ?

Well it all depends Although you can have red, green and blue filters 'cos that's their colour, infra-red [IR] filters come in two varieties eg IR transmitting [for creating fake snowy lansdscapes] and IR block filters that kill IR from sensors to retain 'good' or acceptable colour balance in imaging. Although IR is invisible to the human eye, CCD imaging sensors are very sensitive to IR [~1/3 of overall sensitivity] and most colour camera have an IR block filter over the sensor.

For what it's worth use, I use for maximum sensitivity a monochrome CCD [no red/green/blue or IR block filtration] for imaging the nightsky and find my camera is maybe x3 'faster' than a comparable colour camera and this counts when exposures can be 15-30minutes long [or 45m - 90m for colour]

[Morph]

Thank you, very informative.