Oof! Until now I have never owned any lens longer than 135mm so I had no idea that 100 yards was such a long distance for taking a picture. In Hawaii I have visited surfing beaches where the surfers were quite some distance offshore. There were photographers there on the beach, making movies. I later viewed one of the movies and the surfer was very up close and we viewed his ride all the way in. It was amazing. I remembered that the lenses looked long to me that day at the beach, but not so long as to make me say Wow!

No rule of thumb for doing distance-to-MM estimates was offered so I suppose that none exists. I had hoped to photograph surfers but I see that doing so won't be practical for now. That is.... from the comments here, it seems my idea of shooting close-ups of people at distance would mandate use of a lens that would (a) give me a hernia using it, and (b) empty my billfold for quite a while.

Even so, this is an interesting thread. I learned from it. I am going to look into acquiring the Tamron 150-600 suggested by Drive-By. If I can afford it, I will likely buy it. Otherwise I will start dropping hints at family get-togethers ... I have a birthday in a few months.
Yes, I have. I had end zone tickets for an Alabama vs Texas U game. In the first half, I was at the 'Bama end of the field, so much of the best action was at the other end zone. So I was watching stuff mostly about a hundred yards distant. The second half was visually better because 'Bama was scoring right in front of us. Obviously, TU got smashed.

Oof! Until now I have never owned any lens longer than 135mm so I had no idea that 100 yards was such a long distance for taking a picture. In Hawaii I have visited surfing beaches where the surfers were quite some distance offshore. There were photographers there on the beach, making movies. I later viewed one of the movies and the surfer was very up close and we viewed his ride all the way in. It was amazing. I remembered that the lenses looked long to me that day at the beach, but not so long as to make me say Wow!

No rule of thumb for doing distance-to-MM estimates was offered so I suppose that none exists. I had hoped to photograph surfers but I see that doing so won't be practical for now. That is.... from the comments here, it seems my idea of shooting close-ups of people at distance would mandate use of a lens that would (a) give me a hernia using it, and (b) empty my billfold for quite a while.

Even so, this is an interesting thread. I learned from it. I am going to look into acquiring the Tamron 150-600 suggested by Drive-By. If I can afford it, I will likely buy it. Otherwise I will start dropping hints at family get-togethers ... I have a birthday in a few months.
Yes, I have. I had end zone tickets for an Alabama vs Texas U game. In the first half, I was at the 'Bama end of the field, so much of the best action was at the other end zone. So I was watching stuff mostly about a hundred yards distant. The second half was visually better because 'Bama was scoring right in front of us. Obviously, TU got smashed.