I have this really old camera (Sony DCR PC9) which can detect ir light. Does that mean it has no filters and just needs the one to block normal light?

I have found this filter which might work:

http://cgi.ebay.co.uk/58mm-58-mm-850nm-850-Infrared-IR-Pass-X-Ray-Filter_W0QQitemZ250289030182QQcmdZViewItem?hash=item250289030182&_trkparms=72:12|39:1|66:2|65:12|240:1318&_trksid=p3286.c0.m14

It says 850nm and my IRs are 850nm so it should work!