We test the Pentax K100D digital camera for its suitability for infrared photography.
1/8 second at f3.5 and 200ISO
2 seconds at f16 and 200ISO
What we found when we put a Hoya R72 filter on the camera was that the new Pentax K100D has a fairly weak infrared blocking filter. So exposure times are not so very long as many recent digital cameras have.
Here is the image straight from the camera without a custom white balance:
This exposure was 0.3 second at f8 and 200ISO
The histogram (PS CS3):
And the individual color channels:
200ISO – 0.3 sec f8
400ISO 1/8 sec f8
800ISO 1/10 sec f8
1600ISO 1/30 sec f8
3200ISO 1/60 sec f8
So the Pentax K100D is quite a capable infrared camera unconverted, just the exposures are out of the handheld range except at wide apertures and higher ISO settings. But at least the exposures are not so long that you have issues with common moving objects.
So if you have a Pentax K100D, go ahead and get a Hoya R72 filter or similar and go get some shooting done.