In article , M-M
wrote:

removing the infrared cut filter turns it into a full spectrum camera,
which covers visible light *and* infrared. you now need an infrared
pass filter on the lens to cut visible light if you want infrared.

Correct.

The old Olympus C2020 never had an IR filter and works well for IR
photography if an R72 is used with it.

for some definition of 'well'. that camera is awful and uses the
completely obsolete smartmedia.

anyway, several old digicams didn't have an infrared cut filter or had
a very weak one. they generally got stronger with every revision.