I did not know that!Yes, it was a nostalgic read for me today. I am a bit surprised that no one picked up on why I was confused about the aperture not corresponding with the range on the dial.
It is because I had the lens focussed right in close, and I couldn't achieve f2.8, I think it was noted that the aperture range was shifting 2 stops. I now know that this is a characteristic of all macro lenses.
And the learning keeps on coming!
Hence, another reason why a long macro is preferable to a short?