I just bought on Amazon a look-alike copy of the ET-101 hood (a JJC LH-101) for the RF 800mm f/11. At present, I have a Marumi 95mm filter on the lens to protect it in the absence of a hood. The knock-off filter doesn't fit over the filter. Does the original lens hood fit over such a filter? The diameter of the lens casing looks pretty slim and maybe it is a problem of the knurled ring of this particular filter being on the large side - I have used it with no problems on other 95mm filter lenses, and it doesn't affect IQ, though I tend not to use filters on telephotos and prefer just a lens hood.