Pork Pie, that was a Nikon F2 with a 500 mm mirror. The 500 was the first long lens that I purchased. It was small as compared to a conventional telephoto and easy to carry but it has the hot spot in the middle of the image because of the "folding mirror" that allowed the lens to be short.
Then I bought a Nikon 400 that was a conventional telephoto. These were both manual focus lenses. I could not use the 400 to do professional basket ball, too long an too hard to follow focus. Then I bought the Internal focus Nikkor f2.8 300 mm. That was OK to use at the basketball games because it was so bright and focusing was effortless. After I bought that lens was when I moved up close to the course and I was even able to shoot sequences if I needed to.
I think the 300 was the most enjoyable long lens I have ever owned. I have an auto focus auto exposure 300 for the Nikon and it is very convenient but it doesn't feel the same to shoot it as did the manual focus, extra low dispersion glass lens.
FREUD