you really don't need to use film to do IR photography - if you already have an IR filter you can use it on your K20 without modifying it - though be prepared for some long exposures.
the left side of this image is a glass of coke shot under visible light, the IR image is on the right. Due to the law of forbidden transmission the coke in the glass looks like plain soda water when seen in IR wavelengths.
On the left: the visible light image was captured at 1/500th ISO100 f/8. On the right the IR image was 25s ISO100 f/8 and I used the Hoya R72 filter [which transmits approximately 100% of the light at 720Nm and beyond]
Last edited by Digitalis; 01-28-2015 at 12:36 AM.