After finding out that the 990 has different internal features many users were disappointed that their old IR filters didn't work with the 990, Cory Shubert a regular reader and contributor to our forums sent me a note pointing out his webpages covering the use of 89B IR filters on the 990 and some of his results (which look rather good).
 

Click here for Cory's Pixelagogo Coolpix 990 Infrared pages