Originally Posted by Al Downie
That's nuts. It contains no optical elements - it's just a flippin' lens cap!
As a rough guide anything that encroaches into the path of either lens is banned, by all means if you are only using it as a lens cap cut off the triangles that encroach into the eyebell lenses path then you'd be able to use it in a UKAHFT natioanl.
However if we start allowing one device that encroaches where do we then draw the line, would we have to then limit the type & amount of encroachment. If that every happened we would then be unfair to the person who came outside those limits..