using black glass and infra red filters

[tlc]

can these be used on digital cameras? if so, what types of results would you get?

or is this just a squirrley idea? :p

[mcminty]

Without any research or authority on the subject, and just going on what I can remember:


I believe you can use IR filters on digital cameras, although most sensors have a filter in front of the sensor itself. Unlike the filter you are thinking of, this filter removes IR waves from the incoming light. This means that the cameras, for the most part, are very insensitive to IR light.

Filters such as the Hoya 72R can get results on DSLRs, although long shutter times are required (as the cameras are insensitive to IR light). There are some modifications that can be carried out on DSLRs, although these would certianly void the warranty.

It should be noted that many lenses have a 'hotspot' produced when recording IR. It usually looks like a circle of lighter colour, like some lens flare.


Some digicams are known for their ability to record IR light. I am not sure of the names of these cameras...



That's about all I know on the subject. If I got anything wrong... whoops :D

Andrew.

[Dchemist]

I tried this filter on my 24-105 and 20D: B+W 77mm Dark Red 092 (89B) Infrared Glass Filter and it seemed to work fine. The camera has sufficient light to focus in daylight (confirming Bryan Peterson comments in his book on Exposure) and you get a dark red image in your raw file. You can convert it to black and white in PS. In the end I did not see much difference between using the filter and simply using only the red channel from the normal readout... Dennis

[tlc]

well i dont think i will be wasting my money then. thanks for the help.

[Dchemist]

I did not mention that with these filters the image in the viewfinder is quite dim... you would need a bright subject. Good luck with it.