Vignetting using such filter will depends on the lens used. If like me using DX lens it may not help.
tomcat said:What filter system is this filter compatible with? The 3"x3" Lee filter system? In any case, unless the DSLR is a full frame one like the 1Ds, the multiplication factor of 1.5-1.6x would ensure that there is no vignetting when this filter is used on a 77mm lens.
The other alternative is to get the Cokin P007 Infrared filter. That will fit a 77mm lens with the 77mm adapter ring. I know because I have one and it fits properly on my 77mm lens. CP is selling this filter at $36.20 but unfortunately they have no stock at the moment (I bought the last one). Do note that this filter though it is rated at the same Wratten 89B as the Hoya R72 filter, is not completely opaque and may not work well for those DSLRs with long exposure time requirements for IR photography.