On Tue, 4 Nov 2003, Rob Studdert wrote: > On 3 Nov 2003 at 22:35, John Francis wrote: > > Oops. Make that IR and near-IR, not UV. > > > > There is increased sensitivity into the UV, too, but that causes > > things to look more blue, not more red. Proof-read more carefully! > > If the *ist D is like most other cameras it will have a hot mirror (IR cut) > directly in front of the CCD (which may also act as a anti-aliasing diffuser). > I have seen a few web sites that test the effect of IR cut filters and most > showed marginal effects.
The *ist D filter isn't very strong. You can put a near-IR filter onto the camera (such as the Hoya R72) and shoot handheld IR shots. Most digital cameras don't do that and you end up needing to mount them on a tripod for IR shots. If you don't have the filter you can also just point a IR remote at the camera and take a picture and you'll see the IR LEDs lighting up. http://phred.org/~alex/pictures/pentax-ir/reduced/olympics-ir.jpg is an IR shot taken with the *ist D and Hoya R72 filter. I don't have EXIF on there anymore, but by memory it was shot at f4 and 1/60. http://phred.org/~alex/pictures/pentax-ir/ is full of other shots straight out of the camera from when I was playing with this (none have interesting subject matter). alex
