I was planning on sending my 300D away to get the IR filter removed so it would be more sensitive to the Hydrogen alpha light. The inbuilt IR filter is pretty severe in the red spectrum. I'm not sure what the IR filter excludes in regard to its overlap into the red spectrum for the Nikon 70 and I not heard of anyone modding one. I wouldn't worry too much about it though, you'll still be able to great photos with it, ..............until you convert to a canon